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  • Tips &amp; Tricks: How to crawl a SSL enabled Oracle E-Business Suite

    - by Rajesh Ghosh
    Oracle E-Business Suite can be integrated with Oracle Secure Enterprise Search for a superior end user experience and enhanced data retrieval capabilities. Before end-users can perform search operations, data has to be crawled and indexed into Oracle SES server. However if the Oracle E-Business Suite instance is on SSL, some additional configurations are needed in Oracle SES server as well as in Oracle Search Modeler, before a search object can be deployed and crawled. The process involves the following steps: Step 1: Export the SSL certificate of Oracle E-Business Suite Access the Oracle E-business Suite instance from a web browser. You should be able to locate a security or certificate icon somewhere in the browser toolbar or status bar, depending on which browser you are using. Click on it and you should be able to view the certificate as well as export it to a local file. While exporting make sure that you use “DER encoded” format. Step 2: Import the SSL certificate into Oracle Secure Enterprise server’s java key-store Oracle SES (10.1.8.4) by default ships a JDK under $ORACLE_HOME. The Oracle SES mid-tier uses this jdk to start the oc4j container services. In this step the Oracle E-Business Suite’s SSL certificate which has been exported in step #1, has to be imported into the Oracle SES server’s java key store. Perform the following: Copy the certificate file onto the server where Oracle SES server is running; under $ORACLE_HOME/jdk/jre/lib/security/cacerts. “ORACLE_HOME” points to the Oracle SES oracle home. Set the JAVA_HOME environment variable to $ORACLE_HOME/jdk. Append $JAVA_HOME/bin to the PATH environment variable Issue the command :  “keytool -import -keystore keystore.jks -trustcacerts -alias myOHS –file ebs.crt” . Please substitute “ebs.crt” with the name of the certificate file you copied in step #2.1. The default key-store password “changeit”. Enter the same when prompted. If successful this process will end with a message saying “certificate successfully imported”. Step 3: Import the SSL certificate into Search Modeler java key-store Unlike Oracle SES, Search Modeler is not shipped with a bundled JDK. If you are using standalone OC4J, then you actually use an external JDK to start the oc4j container services. If you are using IAS instance then the JDK comes bundled with the IAS installation. Perform the following: Copy the certificate file onto the server where Search Modeler application is running; under $JDK_HOME/jre/lib/security/cacerts. “JDK_HOME” points to the JDK directory depending on whether you are using external JDK or a bundled one. Set the JAVA_HOME environment variable to JDK directory. Append $JAVA_HOME/bin to the PATH environment variable Issue the command :  “keytool -import -keystore keystore.jks -trustcacerts -alias myOHS –file ebs.crt” . Please substitute “ebs.crt” with the name of the certificate file you copied in step #3.1. The default key-store password “changeit”. Enter the same when prompted. If successful this process will end with a message saying “certificate successfully imported”. Once you have completed the above steps successfully, you can deploy the search objects using Search Modeler and then start crawling them as well.

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  • Handling null values and missing object properties in Silverlight 4

    - by PeterTweed
    Before Silverlight 4 to bind a data object to the UI and display a message associated with either a null value or if the binding path was wrong, you would need to write a Converter.  In Silverlight 4 we find the addition of the markup extensions TargetNullValue and FallbackValue that allows us to display a value when a null value is found in the bound to property and display a value when the property being bound to is not found. This post will show you how to use both markup extensions. Steps: 1. Create a new Silverlight 4 application 2. In the body of the MainPage.xaml.cs file replace the MainPage class with the following code:     public partial class MainPage : UserControl     {         public MainPage()         {             InitializeComponent();             this.Loaded += new RoutedEventHandler(MainPage_Loaded);         }           void MainPage_Loaded(object sender, RoutedEventArgs e)         {             person p = new person() { NameValue = "Peter Tweed" };             this.DataContext = p;         }     }       public class person     {         public string NameValue { get; set; }         public string TitleValue { get; set; }     } This code defines a class called person with two properties.  A new instance of the class is created, only defining the value for one of the properties and bound to the DataContext of the page. 3.  In the MainPage.xaml file copy the following XAML into the LayoutRoot grid:         <Grid.RowDefinitions>             <RowDefinition Height="60*" />             <RowDefinition Height="28*" />             <RowDefinition Height="28*" />             <RowDefinition Height="30*" />             <RowDefinition Height="154*" />         </Grid.RowDefinitions>         <Grid.ColumnDefinitions>             <ColumnDefinition Width="86*" />             <ColumnDefinition Width="314*" />         </Grid.ColumnDefinitions>         <TextBlock Grid.Row="1" Height="23" HorizontalAlignment="Left" Margin="32,0,0,0" Name="textBlock1" Text="Name Value:" VerticalAlignment="Top" />         <TextBlock Grid.Row="2" Height="23" HorizontalAlignment="Left" Margin="32,0,0,0" Name="textBlock2" Text="Title Value:" VerticalAlignment="Top" />         <TextBlock Grid.Row="3" Height="23" HorizontalAlignment="Left" Margin="32,0,0,0" Name="textBlock3" Text="Non Existant Value:" VerticalAlignment="Top" />         <TextBlock Grid.Column="1" Grid.Row="1" Height="23" HorizontalAlignment="Left" Name="textBlock4" Text="{Binding NameValue, TargetNullValue='No Name!!!!!!!'}" VerticalAlignment="Top" Margin="6,0,0,0" />         <TextBlock Grid.Column="1" Grid.Row="2" Height="23" HorizontalAlignment="Left" Name="textBlock5" Text="{Binding TitleValue, TargetNullValue='No Title!!!!!!!'}" VerticalAlignment="Top" Margin="6,0,0,0" />         <TextBlock Grid.Column="1" Grid.Row="3" Height="23" HorizontalAlignment="Left" Margin="6,0,0,0" Name="textBlock6" Text="{Binding AgeValue, FallbackValue='No such property!'}" VerticalAlignment="Top" />    This XAML defines three textblocks – two of which use the TargetNull and one that uses the FallbackValue markup extensions.  4. Run the application and see the person name displayed as defined for the person object, the expected string displayed for the TargetNullValue when no value exists for the boudn property and the expected string displayed for the FallbackValue when the property bound to is not found on the bound object. It's that easy!

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  • Framework 4 Features: Login Id Support

    - by Anthony Shorten
    Given that Oracle Utilities Application Framework 4 is available as part of Mobile Work Force Management and other product progressively I am preparing a number of short but sweet blog entries highlighting some of the new functionality that has been implemented. This is the first entry and it is on a new security feature called Login Id. In past releases of the Oracle Utilities Application Framework, the userid used for authentication and authorization was limited to eight (8) characters in length. This mirrored what the market required in the past with LAN userids and even legacy userids being that length. The technology market has since progressed to longer userid lengths. It is very common to hear that email addresses are being used as credentials for production systems. To achieve this in past versions of the Oracle Utilities Application Framework, sites had to introduce a short userid (8 characters in length) as an alias in your preferred security store. You then configured your J2EE Web Application Server to use the alias as credentials. This sometimes was a standard feaure of the security store and/or the J2EE Web Application Server, if you were lucky. If not, some java code has to be written to implement the solution. In Oracle Utilities Application Framework 4 we introduced a new attribute on the user object called Login Id. The Login Id can be up to 256 characters in length and is an alternative to the existing userid stored on the user object. This means the Oracle Utilities Application Framework can support both long and short userids. For backward compatibility we use the Login Id for authentication but the short userid for authorization and auditing. The user object within the Oracle Utilities Application Framework holds the translation. Backward compatibility is always a consideration in any of our designs for future or changed functionality. You will see reference to this fact in the blog entries I will be composing over the next few months. We have also thought about the flexibility in implementing this feature. The Login Id can be the same value of the Userid (the default for backward compatibility) or can be different. Both the Login Id and Userid have to be unique. This avoids sharing of credentials and is also backward compatible. You can manually enter the Login Id or provision it from Oracle Identity Manager (or other tool). If you use the Login Id only, then we will not autogenerate a short userid automatically as the rules for this can vary from site to site. You have a number of options there. Most Identity provisioning tools can generate a short userid at user creation time and this can be used. If you do not use provisioning tools, then you can write a class extension using the SDK to autoegenerate the userid based upon your sites preference. When we designed the feature there were lots of styles of generating userids (random, initial and surname, numbers etc). We could not really see a clear winner in that respect so we just allowed the extension to be inserted in if necessary. Most customers indicated to us that identity provisioning was the preferred way. This is why we released an Oracle Identity Manager integration with the framework. The Login id is case sensitive now which was not supported under userid. The introduction of the Login Id allows the product to offer flexible options when configuring security whilst maintaining backward compatibility.

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  • Big Data – Operational Databases Supporting Big Data – Columnar, Graph and Spatial Database – Day 14 of 21

    - by Pinal Dave
    In yesterday’s blog post we learned the importance of the Key-Value Pair Databases and Document Databases in the Big Data Story. In this article we will understand the role of Columnar, Graph and Spatial Database supporting Big Data Story. Now we will see a few of the examples of the operational databases. Relational Databases (The day before yesterday’s post) NoSQL Databases (The day before yesterday’s post) Key-Value Pair Databases (Yesterday’s post) Document Databases (Yesterday’s post) Columnar Databases (Tomorrow’s post) Graph Databases (Today’s post) Spatial Databases (Today’s post) Columnar Databases  Relational Database is a row store database or a row oriented database. Columnar databases are column oriented or column store databases. As we discussed earlier in Big Data we have different kinds of data and we need to store different kinds of data in the database. When we have columnar database it is very easy to do so as we can just add a new column to the columnar database. HBase is one of the most popular columnar databases. It uses Hadoop file system and MapReduce for its core data storage. However, remember this is not a good solution for every application. This is particularly good for the database where there is high volume incremental data is gathered and processed. Graph Databases For a highly interconnected data it is suitable to use Graph Database. This database has node relationship structure. Nodes and relationships contain a Key Value Pair where data is stored. The major advantage of this database is that it supports faster navigation among various relationships. For example, Facebook uses a graph database to list and demonstrate various relationships between users. Neo4J is one of the most popular open source graph database. One of the major dis-advantage of the Graph Database is that it is not possible to self-reference (self joins in the RDBMS terms) and there might be real world scenarios where this might be required and graph database does not support it. Spatial Databases  We all use Foursquare, Google+ as well Facebook Check-ins for location aware check-ins. All the location aware applications figure out the position of the phone with the help of Global Positioning System (GPS). Think about it, so many different users at different location in the world and checking-in all together. Additionally, the applications now feature reach and users are demanding more and more information from them, for example like movies, coffee shop or places see. They are all running with the help of Spatial Databases. Spatial data are standardize by the Open Geospatial Consortium known as OGC. Spatial data helps answering many interesting questions like “Distance between two locations, area of interesting places etc.” When we think of it, it is very clear that handing spatial data and returning meaningful result is one big task when there are millions of users moving dynamically from one place to another place & requesting various spatial information. PostGIS/OpenGIS suite is very popular spatial database. It runs as a layer implementation on the RDBMS PostgreSQL. This makes it totally unique as it offers best from both the worlds. Courtesy: mushroom network Tomorrow In tomorrow’s blog post we will discuss about very important components of the Big Data Ecosystem – Hive. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Big Data, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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  • jtreg update, December 2012

    - by jjg
    There is a new version of jtreg available. The primary new feature is support for tests that have been written for use with TestNG, the popular open source testing framework. TestNG is supported by a variety of tools and plugins, which means that it is now possible to develop tests for OpenJDK using those tools, while still retaining the ability to have the tests be part of the OpenJDK test suite, and run with a single test harness, jtreg. jtreg can be downloaded from the OpenJDK jtreg page: http://openjdk.java.net/jtreg. TestNG support jtreg supports both single TestNG tests, which can be freely intermixed with other types of jtreg tests, and groups of TestNG tests. A single TestNG test class can be compiled and run by providing a test description using the new action tag: @run testng classname The test will be executed by using org.testng.TestNG. No main method is required. A group of TestNG tests organized in a standard package hierarchy can also be compiled and run by jtreg. Any such group must be identified by specifying the root directory of the package hierarchy. You can either do this in the top level TEST.ROOT file, or in a TEST.properties file in any subdirectory enclosing the group of tests. In either case, add a line to the file of the form: TestNG.dirs = dir ... Directories beginning with '/' are evaluated relative to the root directory of the test suite; otherwise they are evaluated relative to the directory containing the declaring file. In particular, note that you can simply use "TestNG.dirs = ." in a TEST.properties file in the root directory of the test group's package hierarchy. No additional test descriptions are necessary, but test descriptions containing information tags, such as @bug, @summary, etc are permitted. All the Java source files in the group will be compiled if necessary, before any of the tests in the group are run. The selected tests within the group will be run, one at a time, using org.testng.TestNG. Library classes The specification for the @library tag has been extended so that any paths beginning with '/' will be evaluated relative to the root directory of the test suite. In addition, some bugs have been fixed that prevented sharing the compiled versions of library classes between tests in different directories. Note: This has uncovered some issues in tests that use a combination of @build and @library tags, such that some tests may fail unexpectedly with ClassNotFoundException. The workaround for now is to ensure that library classes are listed before the test classes in any @build tags. To specify one or more library directories for a group of TestNG tests, add a line of the following form to the TEST.properties file in the root directory of the group's package hierarchy: lib.dirs = dir ... As before, directories beginning with '/' are evaluated relative to the root directory of the test suite; otherwise they are evaluated relative to the directory containing the declaring file. The libraries will be available to all classes in the group; you cannot specify different libraries for different tests within the group. Coming soon ... From this point on, jtreg development will be using the new jtreg repository in the OpenJDK code-tools project. There is a new email alias jtreg-dev at openjdk.java.net for discussions about jtreg development. The existing alias jtreg-use at openjdk.java.net will continue to be available for questions about using jtreg. For more information ... An updated version of the jtreg Tag Language Specification is being prepared, and will be made available when it is ready. In the meantime, you can find more information about the support for TestNG by executing the following command: $ jtreg -onlinehelp TestNG For more information on TestNG itself, visit testng.org.

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  • A proposal for #DAX Code Formatting #ssas #powerpivot #tabular

    - by Marco Russo (SQLBI)
    I recently published a set of rules for DAX code formatting. The following is an example of what I obtain: CALCULATE (     SUMX (         Orders,         Orders[Amount]     ),     FILTER (         ALL ( Customers ),         CALCULATE (             COUNTROWS ( Sales ),             ALL ( Calendar[Date] )         ) > 42 + 8 – 25 * ( 3 - 1 )             + 2 – 1 + 2 – 1             + CALCULATE (                   2 + 2 – 2                   + 2 - 2               )             – CALCULATE ( 4 )     ) ) The goal is to improve code readability and I look forward to implement a code formatting feature in DAX Studio. The DAX Editor already supports the rules described in the article. I am also considering whether to add a rule specific for ADDCOLUMNS / SUMMARIZE because I would like to see the “pairs” of arguments to define a column in the same row or with a special indentation rule (DAX expression for a column is indented in the line following the column name). EVALUATE CALCULATETABLE (        CALCULATETABLE (         SUMMARIZE (             Audience,             'Date'[Year],             Individuals[Gender],             Individuals[AgeRange],             "Num of Rows", FORMAT (COUNTROWS (Audience), "#,#"),             "Weighted Mean Age",                 SUMX (Audience, Audience[Weight] * Audience[Age]) / SUM (Audience[Weight])         ),         SUMMARIZE (             BridgeIndividualsTargets,             Individuals[ID_Individual]         ),         Audience[Weight] > 0        ),        Targets[Target] = "Maschi",     'Date'[Year] = 2010,     'Date'[MonthName] = "January" ) I would like to get feedback for that – you can use comments here or comments in original article. Thanks!

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  • SQL SERVER – Curious Case of Disappearing Rows – ON UPDATE CASCADE and ON DELETE CASCADE – T-SQL Example – Part 2 of 2

    - by pinaldave
    Yesterday I wrote a real world story of how a friend who thought they have an issue with intrusion or virus whereas the issue was really in the code. I strongly suggest you read my earlier blog post Curious Case of Disappearing Rows – ON UPDATE CASCADE and ON DELETE CASCADE – Part 1 of 2 before continuing this blog post as this is second part of the first blog post. Let me reproduce the simple scenario in T-SQL. Building Sample Data USE [TestDB] GO -- Creating Table Products CREATE TABLE [dbo].[Products]( [ProductID] [int] NOT NULL, [ProductDesc] [varchar](50) NOT NULL, CONSTRAINT [PK_Products] PRIMARY KEY CLUSTERED ( [ProductID] ASC )) ON [PRIMARY] GO -- Creating Table ProductDetails CREATE TABLE [dbo].[ProductDetails]( [ProductDetailID] [int] NOT NULL, [ProductID] [int] NOT NULL, [Total] [int] NOT NULL, CONSTRAINT [PK_ProductDetails] PRIMARY KEY CLUSTERED ( [ProductDetailID] ASC )) ON [PRIMARY] GO ALTER TABLE [dbo].[ProductDetails] WITH CHECK ADD CONSTRAINT [FK_ProductDetails_Products] FOREIGN KEY([ProductID]) REFERENCES [dbo].[Products] ([ProductID]) ON UPDATE CASCADE ON DELETE CASCADE GO -- Insert Data into Table USE TestDB GO INSERT INTO Products (ProductID, ProductDesc) SELECT 1, 'Bike' UNION ALL SELECT 2, 'Car' UNION ALL SELECT 3, 'Books' GO INSERT INTO ProductDetails ([ProductDetailID],[ProductID],[Total]) SELECT 1, 1, 200 UNION ALL SELECT 2, 1, 100 UNION ALL SELECT 3, 1, 111 UNION ALL SELECT 4, 2, 200 UNION ALL SELECT 5, 3, 100 UNION ALL SELECT 6, 3, 100 UNION ALL SELECT 7, 3, 200 GO Select Data from Tables -- Selecting Data SELECT * FROM Products SELECT * FROM ProductDetails GO Delete Data from Products Table -- Deleting Data DELETE FROM Products WHERE ProductID = 1 GO Select Data from Tables Again -- Selecting Data SELECT * FROM Products SELECT * FROM ProductDetails GO Clean up Data -- Clean up DROP TABLE ProductDetails DROP TABLE Products GO My friend was confused as there was no delete was firing over ProductsDetails Table still there was a delete happening. The reason was because there is a foreign key created between Products and ProductsDetails Table with the keywords ON DELETE CASCADE. Due to ON DELETE CASCADE whenever is specified when the data from Table A is deleted and if it is referenced in another table using foreign key it will be deleted as well. Workaround 1: Design Changes – 3 Tables Change the design to have more than two tables. Create One Product Mater Table with all the products. It should historically store all the products list in it. No products should be ever removed from it. Add another table called Current Product and it should contain only the table which should be visible in the product catalogue. Another table should be called as ProductHistory table. There should be no use of CASCADE keyword among them. Workaround 2: Design Changes - Column IsVisible You can keep the same two tables. 1) Products and 2) ProductsDetails. Add a column with BIT datatype to it and name it as a IsVisible. Now change your application code to display the catalogue based on this column. There should be no need to delete anything. Workaround 3: Bad Advices (Bad advises begins here) The reason I have said bad advices because these are going to be bad advices for sure. You should make necessary design changes and not use poor workarounds which can damage the system and database integrity further. Here are the examples 1) Do not delete the data – well, this is not a real solution but can give time to implement design changes. 2) Do not have ON CASCADE DELETE – in this case, you will have entry in productsdetails which will have no corresponding product id and later on there will be lots of confusion. 3) Duplicate Data – you can have all the data of the product table move to the product details table and repeat them at each row. Now remove CASCADE code. This will let you delete the product table rows without any issue. There are so many things wrong this suggestion, that I will not even start here. (Bad advises ends here)  Well, did I miss anything? Please help me with your suggestions. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • Using Solaris zfs + iscsi targets with Oracle VM

    - by wim.coekaerts
    I was playing with my Oracle VM setup and needed some shared storage that was block based. I did not have a storage array available but I did have a solaris box, that I use for Oracle VDI, available. I set up a few iscsi targets on this solaris server and exported them to my 2 Oracle VM servers. Here's how I did this : (1) On the solaris side : # zpool list NAME SIZE USED AVAIL CAP HEALTH ALTROOT rpool 544G 129G 415G 23% ONLINE - I just have a simple zpool, called rpool, on this box. It has plenty of space available for my needs. So I will use rpool and I will create 5 50gb vols : zfs create -V 50G rpool/ovm1 zfs create -V 50G rpool/ovm2 zfs create -V 50G rpool/ovm3 zfs create -V 50G rpool/ovm4 zfs create -V 50G rpool/ovm5 I want to use these volumes for iscsi so I have to enable them as shared iscsi devices : zfs set shareiscsi=on rpool/ovm1 zfs set shareiscsi=on rpool/ovm2 zfs set shareiscsi=on rpool/ovm3 zfs set shareiscsi=on rpool/ovm4 zfs set shareiscsi=on rpool/ovm5 The command iscsitadm list target should list these devices so make sure they show up. # iscsitadm list target Target: rpool/ovm1 iSCSI Name: iqn.1986-03.com.sun:02:896c766c-0943-4da5-d47e-9575b5a0be36 Connections: 2 Target: rpool/ovm2 iSCSI Name: iqn.1986-03.com.sun:02:a3116b46-73e0-e8c2-e80c-9a4f71aff069 Connections: 2 Target: rpool/ovm3 iSCSI Name: iqn.1986-03.com.sun:02:a838c400-2730-c0d6-f2c2-ee186a0261c1 Connections: 2 Target: rpool/ovm4 iSCSI Name: iqn.1986-03.com.sun:02:2e046afb-d66d-4f3f-c5de-8115e0ddd931 Connections: 2 Target: rpool/ovm5 iSCSI Name: iqn.1986-03.com.sun:02:66109fbe-81ac-ef05-f85e-ab8c1f34cb43 Connections: 2 At this point I want to make sure that I have some access control on these devices. To make it easier, I will create an alias for my 2 servers and use the alias for the ACL. get the iqn from the 2 servers on my 2 ovm servers (wcoekaer-srv1, wcoekaer-srv2) get the content of /etc/iscsi/initiatorname.iscsi (for each server) InitiatorName=iqn.1986-03.com.sun:01:2a7526f0ffff On the solaris side create the aliases : iscsitadm create initiator -n iqn.1986-03.com.sun:01:2a7526f0ffff wcoekaer-srv1 iscsitadm create initiator -n iqn.1986-03.com.sun:01:e31b08110f1 wcoekaer-srv5 Add the ACL to the targets : iscsitadm modify target -l wcoekaer-srv1 rpool/ovm1 iscsitadm modify target -l wcoekaer-srv1 rpool/ovm2 iscsitadm modify target -l wcoekaer-srv1 rpool/ovm3 iscsitadm modify target -l wcoekaer-srv1 rpool/ovm4 iscsitadm modify target -l wcoekaer-srv1 rpool/ovm5 iscsitadm modify target -l wcoekaer-srv5 rpool/ovm1 iscsitadm modify target -l wcoekaer-srv5 rpool/ovm2 iscsitadm modify target -l wcoekaer-srv5 rpool/ovm3 iscsitadm modify target -l wcoekaer-srv5 rpool/ovm4 iscsitadm modify target -l wcoekaer-srv5 rpool/ovm5 (2) the Oracle VM side On each server just do 2 simple things : # iscsiadm -m discovery -t sendtargets -p ca-vdi1 where ca-vdi1 is my solaris server name # service iscsi restart When I do cat /proc/partitions on my servers I will see the devices show up # cat /proc/partitions major minor #blocks name 8 0 160836480 sda 8 1 104391 sda1 8 2 3148740 sda2 8 3 1052257 sda3 253 0 6377804 dm-0 253 1 6377804 dm-1 253 2 6377804 dm-2 8 16 52428800 sdb 8 32 52428800 sdc 8 48 52428800 sdd 8 80 52428800 sdf 8 64 52428800 sde These 5 new devices sd[b..f] are shared storage for Oracle VM and can be used to pass through to the VM's as phy: devices or put ocfs2 on it and use as shared filesystem storage for dom0 repositories. I am setting up an 11gR2 rac template (the cool stuff Saar did) so I am using my devices to create a 2 node RAC cluster with phy: devices.

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  • Strings in .NET are Enumerable

    - by Scott Dorman
    It seems like there is always some confusion concerning strings in .NET. This is both from developers who are new to the Framework and those that have been working with it for quite some time. Strings in the .NET Framework are represented by the System.String class, which encapsulates the data manipulation, sorting, and searching methods you most commonly perform on string data. In the .NET Framework, you can use System.String (which is the actual type name or the language alias (for C#, string). They are equivalent so use whichever naming convention you prefer but be consistent. Common usage (and my preference) is to use the language alias (string) when referring to the data type and String (the actual type name) when accessing the static members of the class. Many mainstream programming languages (like C and C++) treat strings as a null terminated array of characters. The .NET Framework, however, treats strings as an immutable sequence of Unicode characters which cannot be modified after it has been created. Because strings are immutable, all operations which modify the string contents are actually creating new string instances and returning those. They never modify the original string data. There is one important word in the preceding paragraph which many people tend to miss: sequence. In .NET, strings are treated as a sequence…in fact, they are treated as an enumerable sequence. This can be verified if you look at the class declaration for System.String, as seen below: // Summary:// Represents text as a series of Unicode characters.public sealed class String : IEnumerable, IComparable, IComparable<string>, IEquatable<string> The first interface that String implements is IEnumerable, which has the following definition: // Summary:// Exposes the enumerator, which supports a simple iteration over a non-generic// collection.public interface IEnumerable{ // Summary: // Returns an enumerator that iterates through a collection. // // Returns: // An System.Collections.IEnumerator object that can be used to iterate through // the collection. IEnumerator GetEnumerator();} As a side note, System.Array also implements IEnumerable. Why is that important to know? Simply put, it means that any operation you can perform on an array can also be performed on a string. This allows you to write code such as the following: string s = "The quick brown fox";foreach (var c in s){ System.Diagnostics.Debug.WriteLine(c);}for (int i = 0; i < s.Length; i++){ System.Diagnostics.Debug.WriteLine(s[i]);} If you executed those lines of code in a running application, you would see the following output in the Visual Studio Output window: In the case of a string, these enumerable or array operations return a char (System.Char) rather than a string. That might lead you to believe that you can get around the string immutability restriction by simply treating strings as an array and assigning a new character to a specific index location inside the string, like this: string s = "The quick brown fox";s[2] = 'a';   However, if you were to write such code, the compiler will promptly tell you that you can’t do it: This preserves the notion that strings are immutable and cannot be changed once they are created. (Incidentally, there is no built in way to replace a single character like this. It can be done but it would require converting the string to a character array, changing the appropriate indexed location, and then creating a new string.)

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  • NHibernate Pitfalls: Custom Types and Detecting Changes

    - by Ricardo Peres
    This is part of a series of posts about NHibernate Pitfalls. See the entire collection here. NHibernate supports the declaration of properties of user-defined types, that is, not entities, collections or primitive types. These are used for mapping a database columns, of any type, into a different type, which may not even be an entity; think, for example, of a custom user type that converts a BLOB column into an Image. User types must implement interface NHibernate.UserTypes.IUserType. This interface specifies an Equals method that is used for comparing two instances of the user type. If this method returns false, the entity is marked as dirty, and, when the session is flushed, will trigger an UPDATE. So, in your custom user type, you must implement this carefully so that it is not mistakenly considered changed. For example, you can cache the original column value inside of it, and compare it with the one in the other instance. Let’s see an example implementation of a custom user type that converts a Byte[] from a BLOB column into an Image: 1: [Serializable] 2: public sealed class ImageUserType : IUserType 3: { 4: private Byte[] data = null; 5: 6: public ImageUserType() 7: { 8: this.ImageFormat = ImageFormat.Png; 9: } 10: 11: public ImageFormat ImageFormat 12: { 13: get; 14: set; 15: } 16: 17: public Boolean IsMutable 18: { 19: get 20: { 21: return (true); 22: } 23: } 24: 25: public Object Assemble(Object cached, Object owner) 26: { 27: return (cached); 28: } 29: 30: public Object DeepCopy(Object value) 31: { 32: return (value); 33: } 34: 35: public Object Disassemble(Object value) 36: { 37: return (value); 38: } 39: 40: public new Boolean Equals(Object x, Object y) 41: { 42: return (Object.Equals(x, y)); 43: } 44: 45: public Int32 GetHashCode(Object x) 46: { 47: return ((x != null) ? x.GetHashCode() : 0); 48: } 49: 50: public override Int32 GetHashCode() 51: { 52: return ((this.data != null) ? this.data.GetHashCode() : 0); 53: } 54: 55: public override Boolean Equals(Object obj) 56: { 57: ImageUserType other = obj as ImageUserType; 58: 59: if (other == null) 60: { 61: return (false); 62: } 63: 64: if (Object.ReferenceEquals(this, other) == true) 65: { 66: return (true); 67: } 68: 69: return (this.data.SequenceEqual(other.data)); 70: } 71: 72: public Object NullSafeGet(IDataReader rs, String[] names, Object owner) 73: { 74: Int32 index = rs.GetOrdinal(names[0]); 75: Byte[] data = rs.GetValue(index) as Byte[]; 76: 77: this.data = data as Byte[]; 78: 79: if (data == null) 80: { 81: return (null); 82: } 83: 84: using (MemoryStream stream = new MemoryStream(this.data ?? new Byte[0])) 85: { 86: return (Image.FromStream(stream)); 87: } 88: } 89: 90: public void NullSafeSet(IDbCommand cmd, Object value, Int32 index) 91: { 92: if (value != null) 93: { 94: Image data = value as Image; 95: 96: using (MemoryStream stream = new MemoryStream()) 97: { 98: data.Save(stream, this.ImageFormat); 99: value = stream.ToArray(); 100: } 101: } 102: 103: (cmd.Parameters[index] as DbParameter).Value = value ?? DBNull.Value; 104: } 105: 106: public Object Replace(Object original, Object target, Object owner) 107: { 108: return (original); 109: } 110: 111: public Type ReturnedType 112: { 113: get 114: { 115: return (typeof(Image)); 116: } 117: } 118: 119: public SqlType[] SqlTypes 120: { 121: get 122: { 123: return (new SqlType[] { new SqlType(DbType.Binary) }); 124: } 125: } 126: } In this case, we need to cache the original Byte[] data because it’s not easy to compare two Image instances, unless, of course, they are the same.

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  • Missing Fields and Default Values

    - by PointsToShare
    © 2011 By: Dov Trietsch. All rights reserved Dealing with Missing Fields and Default Values New fields and new default values are not propagated throughout the list. They only apply to new and updated items and not to items already entered. They are only prospective. We need to be able to deal with this issue. Here is a scenario. The user has an old list with old items and adds a new field. The field is not created for any of the old items. Trying to get its value raises an Argument Exception. Here is another: a default value is added to a field. All the old items, where the field was not assigned a value, do not get the new default value. The two can also happen in tandem – a new field is added with a default. The older items have neither. Even better, if the user changes the default value, the old items still carry the old defaults. Let’s go a bit further. You have already written code for the list, be it an event receiver, a feature receiver, a console app or a command extension, in which you span all the fields and run on selected items – some new (no problem) and some old (problems aplenty). Had you written defensive code, you would be able to handle the situation, including similar changes in the future. So, without further ado, here’s how. Instead of just getting the value of a field in an item – item[field].ToString() – use the function below. I use ItemValue(item, fieldname, “mud in your eye”) and if “mud in your eye” is what I get, I know that the item did not have the field.   /// <summary> /// Return the column value or a default value /// </summary> private static string ItemValue(SPItem item, string column, string defaultValue) {     try     {         return item[column].ToString();     }     catch (NullReferenceException ex)     {         return defaultValue;     }     catch (ArgumentException ex)     {         return defaultValue;     } } I also use a similar function to return the default and a funny default-default to ascertain that the default does not exist. Here it is:  /// <summary> /// return a fields default or the "default" default. /// </summary> public static string GetFieldDefault(SPField fld, string defValue) {     try     {         // -- Check if default exists.         return fld.DefaultValue.ToString();     }     catch (NullReferenceException ex)     {         return defValue;     }     catch (ArgumentException ex)     {         return defValue;     } } How is this defensive? You have trapped an expected error and dealt with it. Therefore the program did not stop cold in its track and the required code ran to its end. Now, take a further step - write to a log (See Logging – a log blog). Read your own log every now and then, and act accordingly. That’s all Folks!

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  • Juggling with JDKs on Apple OS X

    - by Blueberry Coder
    I recently got a shiny new MacBook Pro to help me support our ADF Mobile customers. It is really a wonderful piece of hardware, although I am still adjusting to Apple's peculiar keyboard layout. Did you know, for example, that the « delete » key actually performs a « backspace »? But I disgress... As you may know, ADF Mobile development still requires JDeveloper 11gR2, which in turn runs on Java 6. On the other hand, JDeveloper 12c needs JDK 7. I wanted to install both versions, and wasn't sure how to do it.   If you remember, I explained in a previous blog entry how to install JDeveloper 11gR2 on Apple's OS X. The trick was to use the /usr/libexec/java_home command in order to invoke the proper JDK. In this case, I could have done the same thing; the two JDKs can coexist without any problems, since they install in completely different locations. But I wanted more than just installing JDeveloper. I wanted to be able to select my JDK when using the command line as well. On Windows, this is easy, since I keep all my JDKs in a central location. I simply have to move to the appropriate folder or type the folder name in the command I want to execute. Problem is, on OS X, the paths to the JDKs are... let's say convoluted.  Here is the one for Java 6. /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home The Java 7 path is not better, just different. /Library/Java/JavaVirtualMachines/jdk1.7.0_45.jdk/Contents/Home Intuitive, isn't it? Clearly, I needed something better... On OS X, the default command shell is bash. It is possible to configure the shell environment by creating a file named « .profile » in a user's home folder. Thus, I created such a file and put the following inside: export JAVA_7_HOME=$(/usr/libexec/java_home -v1.7) export JAVA_6_HOME=$(/usr/libexec/java_home -v1.6) export JAVA_HOME=$JAVA_7_HOME alias java6='export JAVA_HOME=$JAVA_6_HOME' alias java7='export JAVA_HOME=$JAVA_7_HOME'  The first two lines retrieve the current paths for Java 7 and Java 6 and store them in two environment variables. The third line marks Java 7 as the default. The last two lines create command aliases. Thus, when I type java6, the value for JAVA_HOME is set to JAVA_6_HOME, for example.  I now have an environment which works even better than the one I have on Windows, since I can change my active JDK on a whim. Here a sample, fresh from my terminal window. fdesbien-mac:~ fdesbien$ java6 fdesbien-mac:~ fdesbien$ java -version java version "1.6.0_65" Java(TM) SE Runtime Environment (build 1.6.0_65-b14-462-11M4609) Java HotSpot(TM) 64-Bit Server VM (build 20.65-b04-462, mixed mode) fdesbien-mac:~ fdesbien$ fdesbien-mac:~ fdesbien$ java7 fdesbien-mac:~ fdesbien$ java -version java version "1.7.0_45" Java(TM) SE Runtime Environment (build 1.7.0_45-b18) Java HotSpot(TM) 64-Bit Server VM (build 24.45-b08, mixed mode) fdesbien-mac:~ fdesbien$ Et voilà! Maximum flexibility without downsides, just I like it. 

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  • Formatting made easy - Silverlight 4

    - by PeterTweed
    One of the simplest tasks in business apps is displaying different types of data to be read in the format that the user expects them.  In Silverlight versions until Silverlight 4 this has meant using a Converter to format data during binding.  This involves writing code for the formatting of the data to bind, instead of simply defining the formatting to use for the data in question where you bind the data to the control.   In Silverlight 4 we find the addition of the StringFormat markup extension that allows us to do exactly this.  Of course the nice thing is the ability to use the common formatting conventions available in C# through the String.Format function.   This post will show you how to use three of the common formatting conventions - currency, a defined number of decimal places for a number and a date format.   Steps:   1. Create a new Silverlight 4 application   2. In the body of the MainPage.xaml.cs file replace the MainPage class with the following code:       public partial class MainPage : UserControl     {         public MainPage()         {             InitializeComponent();             this.Loaded += new RoutedEventHandler(MainPage_Loaded);         }           void MainPage_Loaded(object sender, RoutedEventArgs e)         {             info i = new info() { PriceValue = new Decimal(9.2567), DoubleValue = 1.2345678, DateValue = DateTime.Now };             this.DataContext = i;         }     }         public class info     {         public decimal PriceValue { get; set; }         public double DoubleValue { get; set; }         public DateTime DateValue { get; set; }     }   This code defines a class called info with different data types for the three properties.  A new instance of the class is created and bound to the DataContext of the page.   3.  In the MainPage.xaml file copy the following XAML into the LayoutRoot grid:           <Grid.RowDefinitions>             <RowDefinition Height="60*" />             <RowDefinition Height="28*" />             <RowDefinition Height="28*" />             <RowDefinition Height="30*" />             <RowDefinition Height="154*" />         </Grid.RowDefinitions>         <Grid.ColumnDefinitions>             <ColumnDefinition Width="86*" />             <ColumnDefinition Width="314*" />         </Grid.ColumnDefinitions>         <TextBlock Grid.Row="1" Height="23" HorizontalAlignment="Left" Margin="32,0,0,0" Name="textBlock1" Text="Price Value:" VerticalAlignment="Top" />         <TextBlock Grid.Row="2" Height="23" HorizontalAlignment="Left" Margin="32,0,0,0" Name="textBlock2" Text="Decimal Value:" VerticalAlignment="Top" />         <TextBlock Grid.Row="3" Height="23" HorizontalAlignment="Left" Margin="32,0,0,0" Name="textBlock3" Text="Date Value:" VerticalAlignment="Top" />         <TextBlock Grid.Column="1" Grid.Row="1" Height="23" HorizontalAlignment="Left" Name="textBlock4" Text="{Binding PriceValue, StringFormat='C'}" VerticalAlignment="Top" Margin="6,0,0,0" />         <TextBlock Grid.Column="1" Grid.Row="2" Height="23" HorizontalAlignment="Left" Margin="6,0,0,0" Name="textBlock5" Text="{Binding DoubleValue, StringFormat='N3'}" VerticalAlignment="Top" />         <TextBlock Grid.Column="1" Grid.Row="3" Height="23" HorizontalAlignment="Left" Margin="6,0,0,0" Name="textBlock6" Text="{Binding DateValue, StringFormat='yyyy MMM dd'}" VerticalAlignment="Top" />   This XAML defines three textblocks that use the StringFormat markup extension.  The three examples use the C for currency, N3 for a number with 3 decimal places and yyy MM dd for a date that displays year 3 letter month and 2 number date.   4. Run the application and see the data displayed with the correct formatting. It's that easy!

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  • Silverlight Binding with multiple collections

    - by George Evjen
    We're designing some sport specific applications. In one of our views we have a gridview that is bound to an observable collection of Teams. This is pretty straight forward in terms of getting Teams bound to the GridView. <telerik:RadGridView Grid.Row="0" Grid.Column="0" x:Name="UsersGrid" ItemsSource="{Binding TeamResults}" SelectedItem="{Binding SelectedTeam, Mode=TwoWay}"> <telerik:RadGridView.Columns> <telerik:GridViewDataColumn Header="Name/Group" DataMemberBinding="{Binding TeamName}" MinWidth="150"></telerik:GridViewDataColumn> </telerik:RadGridView.Columns> </telerik:RadGridView> We use the observable collection of teams as our items source and then bind the property of TeamName to the first column. You can set the binding to mode=TwoWay, we use a dialog where we edit the selected item, so our binding here is not set to two way. The issue comes when we want to bind to a property that has another collection in it. To continue on our code from above, we have an observable collection of teams, within that collection we have a collection of KeyPeople. We get this collection using RIA Serivces with the code below. return _TeamsRepository.All().Include("KeyPerson"); Here we are getting all the teams and also including the KeyPerson entity. So when we are done with our Load we will end up with an observable collection of Teams with a navigation property / entity of KeyPerson. Within this KeyPerson entity is a list of people associated with that particular team. We want to display the head coach from this list of KeyPersons. This list currently has a list of ten or more people that are bound to this team, but we just want to display the Head Coach in the column next to team name. The issue becomes how do we bind to this included entity? I have found about three different ways to solve this issue. The way that seemed to fit us best is to utilize the features within RIA Services. We can create client side properties that will do the work for us. We will create in the client side library a partial class of Team. We will end up in our library a file that is Team.shared.cs. The code below is what we will put into our partial team class. public KeyPerson Coach        {            get            {                if (this.KeyPerson != null && this.KeyPerson.Any())                { return this.KeyPerson.Where(x => x.RelationshipType == “HeadCoach”).FirstOrDefault(); }                 return null;            }        } We will return just the person that is the Head Coach and then be able to bind that and any other additional properties that we need. <telerik:GridViewDataColumn Header="Coach" DataMemberBinding="{Binding Coach.Name}" MinWidth="150"></telerik:GridViewDataColumn> There are other ways that we could have solved this issue but we felt that creating a partial class through RIA Services best suited our needs.

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  • Can you/should you develop components for ASP.NET MVC?

    - by Vilx-
    Following from the previous question I've started to wonder - is it possible to implement "Components" in ASP.NET MVC (latest version)? And should you? Let's clarify what I mean with a "component". With that I mean a "control" (aka "widget"), similar to those that ASP.NET webforms is built upon. A gridview might be a good example. In webforms I can place on my form a datasource component (one line of code), a gridview component (another line of code) and bind them together (specify an attribute on the gridview). In the codebehind file I fill the datasource with data (a few lines of DB-querying code), and I'm all set. At this point the gridview is a fully functional standalone component. I can open the form, and I'll see all the data. I can sort it by clicking on the column headers; it is split into several pages; I can drag the column headers around and rearrange columns; I can turn on "grouping" mode; etc. And I don't need to write another line of code for any of it. The gridview, as a component, already has all the code tucked away in its classes and assemblies. I just place it on the form, initialize it, and it Just Works. At some times (like sorting or navigation to a different page) it will also perform ajax callbacks to the server, but those too will be handled internally, with my code having no knowledge at all about it. And then there are also events that I can attach if I want to get notified when something happens. In MVC I cannot see a way of doing this cleanly. Sure, there are the partial views, but those only handle half of the problem - they render the initial HTML. Some more can be achieved with client-side Javascript (like column re-arranging), but when the grid needs to do an ajax callback (say, to fetch the next page of data), my code will have to get involved and process that request. At best I guess I can provide some helper methods to process it, but I'll have to write the code that calls them, and also provide a controller method with signature matching the arguments of that callback. I guess that I could make some hacks with global events or special routes or something, but that just seems... hackish. Unelegant. Perhaps this is not the MVC way? Although I've completed one project in it, I'm still far from being an MVC expert. But then what is? In the intranet application that we're building there are dozens upon dozens of such grids. Naturally I want them all to have a unified look & behavior, and I don't want to repeat the same code all over the place. So what's the "MVC" approach to this problem?

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  • SimpleMembership, Membership Providers, Universal Providers and the new ASP.NET 4.5 Web Forms and ASP.NET MVC 4 templates

    - by Jon Galloway
    The ASP.NET MVC 4 Internet template adds some new, very useful features which are built on top of SimpleMembership. These changes add some great features, like a much simpler and extensible membership API and support for OAuth. However, the new account management features require SimpleMembership and won't work against existing ASP.NET Membership Providers. I'll start with a summary of top things you need to know, then dig into a lot more detail. Summary: SimpleMembership has been designed as a replacement for traditional the previous ASP.NET Role and Membership provider system SimpleMembership solves common problems people ran into with the Membership provider system and was designed for modern user / membership / storage needs SimpleMembership integrates with the previous membership system, but you can't use a MembershipProvider with SimpleMembership The new ASP.NET MVC 4 Internet application template AccountController requires SimpleMembership and is not compatible with previous MembershipProviders You can continue to use existing ASP.NET Role and Membership providers in ASP.NET 4.5 and ASP.NET MVC 4 - just not with the ASP.NET MVC 4 AccountController The existing ASP.NET Role and Membership provider system remains supported as is part of the ASP.NET core ASP.NET 4.5 Web Forms does not use SimpleMembership; it implements OAuth on top of ASP.NET Membership The ASP.NET Web Site Administration Tool (WSAT) is not compatible with SimpleMembership The following is the result of a few conversations with Erik Porter (PM for ASP.NET MVC) to make sure I had some the overall details straight, combined with a lot of time digging around in ILSpy and Visual Studio's assembly browsing tools. SimpleMembership: The future of membership for ASP.NET The ASP.NET Membership system was introduces with ASP.NET 2.0 back in 2005. It was designed to solve common site membership requirements at the time, which generally involved username / password based registration and profile storage in SQL Server. It was designed with a few extensibility mechanisms - notably a provider system (which allowed you override some specifics like backing storage) and the ability to store additional profile information (although the additional  profile information was packed into a single column which usually required access through the API). While it's sometimes frustrating to work with, it's held up for seven years - probably since it handles the main use case (username / password based membership in a SQL Server database) smoothly and can be adapted to most other needs (again, often frustrating, but it can work). The ASP.NET Web Pages and WebMatrix efforts allowed the team an opportunity to take a new look at a lot of things - e.g. the Razor syntax started with ASP.NET Web Pages, not ASP.NET MVC. The ASP.NET Web Pages team designed SimpleMembership to (wait for it) simplify the task of dealing with membership. As Matthew Osborn said in his post Using SimpleMembership With ASP.NET WebPages: With the introduction of ASP.NET WebPages and the WebMatrix stack our team has really be focusing on making things simpler for the developer. Based on a lot of customer feedback one of the areas that we wanted to improve was the built in security in ASP.NET. So with this release we took that time to create a new built in (and default for ASP.NET WebPages) security provider. I say provider because the new stuff is still built on the existing ASP.NET framework. So what do we call this new hotness that we have created? Well, none other than SimpleMembership. SimpleMembership is an umbrella term for both SimpleMembership and SimpleRoles. Part of simplifying membership involved fixing some common problems with ASP.NET Membership. Problems with ASP.NET Membership ASP.NET Membership was very obviously designed around a set of assumptions: Users and user information would most likely be stored in a full SQL Server database or in Active Directory User and profile information would be optimized around a set of common attributes (UserName, Password, IsApproved, CreationDate, Comment, Role membership...) and other user profile information would be accessed through a profile provider Some problems fall out of these assumptions. Requires Full SQL Server for default cases The default, and most fully featured providers ASP.NET Membership providers (SQL Membership Provider, SQL Role Provider, SQL Profile Provider) require full SQL Server. They depend on stored procedure support, and they rely on SQL Server cache dependencies, they depend on agents for clean up and maintenance. So the main SQL Server based providers don't work well on SQL Server CE, won't work out of the box on SQL Azure, etc. Note: Cory Fowler recently let me know about these Updated ASP.net scripts for use with Microsoft SQL Azure which do support membership, personalization, profile, and roles. But the fact that we need a support page with a set of separate SQL scripts underscores the underlying problem. Aha, you say! Jon's forgetting the Universal Providers, a.k.a. System.Web.Providers! Hold on a bit, we'll get to those... Custom Membership Providers have to work with a SQL-Server-centric API If you want to work with another database or other membership storage system, you need to to inherit from the provider base classes and override a bunch of methods which are tightly focused on storing a MembershipUser in a relational database. It can be done (and you can often find pretty good ones that have already been written), but it's a good amount of work and often leaves you with ugly code that has a bunch of System.NotImplementedException fun since there are a lot of methods that just don't apply. Designed around a specific view of users, roles and profiles The existing providers are focused on traditional membership - a user has a username and a password, some specific roles on the site (e.g. administrator, premium user), and may have some additional "nice to have" optional information that can be accessed via an API in your application. This doesn't fit well with some modern usage patterns: In OAuth and OpenID, the user doesn't have a password Often these kinds of scenarios map better to user claims or rights instead of monolithic user roles For many sites, profile or other non-traditional information is very important and needs to come from somewhere other than an API call that maps to a database blob What would work a lot better here is a system in which you were able to define your users, rights, and other attributes however you wanted and the membership system worked with your model - not the other way around. Requires specific schema, overflow in blob columns I've already mentioned this a few times, but it bears calling out separately - ASP.NET Membership focuses on SQL Server storage, and that storage is based on a very specific database schema. SimpleMembership as a better membership system As you might have guessed, SimpleMembership was designed to address the above problems. Works with your Schema As Matthew Osborn explains in his Using SimpleMembership With ASP.NET WebPages post, SimpleMembership is designed to integrate with your database schema: All SimpleMembership requires is that there are two columns on your users table so that we can hook up to it – an “ID” column and a “username” column. The important part here is that they can be named whatever you want. For instance username doesn't have to be an alias it could be an email column you just have to tell SimpleMembership to treat that as the “username” used to log in. Matthew's example shows using a very simple user table named Users (it could be named anything) with a UserID and Username column, then a bunch of other columns he wanted in his app. Then we point SimpleMemberhip at that table with a one-liner: WebSecurity.InitializeDatabaseFile("SecurityDemo.sdf", "Users", "UserID", "Username", true); No other tables are needed, the table can be named anything we want, and can have pretty much any schema we want as long as we've got an ID and something that we can map to a username. Broaden database support to the whole SQL Server family While SimpleMembership is not database agnostic, it works across the SQL Server family. It continues to support full SQL Server, but it also works with SQL Azure, SQL Server CE, SQL Server Express, and LocalDB. Everything's implemented as SQL calls rather than requiring stored procedures, views, agents, and change notifications. Note that SimpleMembership still requires some flavor of SQL Server - it won't work with MySQL, NoSQL databases, etc. You can take a look at the code in WebMatrix.WebData.dll using a tool like ILSpy if you'd like to see why - there places where SQL Server specific SQL statements are being executed, especially when creating and initializing tables. It seems like you might be able to work with another database if you created the tables separately, but I haven't tried it and it's not supported at this point. Note: I'm thinking it would be possible for SimpleMembership (or something compatible) to run Entity Framework so it would work with any database EF supports. That seems useful to me - thoughts? Note: SimpleMembership has the same database support - anything in the SQL Server family - that Universal Providers brings to the ASP.NET Membership system. Easy to with Entity Framework Code First The problem with with ASP.NET Membership's system for storing additional account information is that it's the gate keeper. That means you're stuck with its schema and accessing profile information through its API. SimpleMembership flips that around by allowing you to use any table as a user store. That means you're in control of the user profile information, and you can access it however you'd like - it's just data. Let's look at a practical based on the AccountModel.cs class in an ASP.NET MVC 4 Internet project. Here I'm adding a Birthday property to the UserProfile class. [Table("UserProfile")] public class UserProfile { [Key] [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)] public int UserId { get; set; } public string UserName { get; set; } public DateTime Birthday { get; set; } } Now if I want to access that information, I can just grab the account by username and read the value. var context = new UsersContext(); var username = User.Identity.Name; var user = context.UserProfiles.SingleOrDefault(u => u.UserName == username); var birthday = user.Birthday; So instead of thinking of SimpleMembership as a big membership API, think of it as something that handles membership based on your user database. In SimpleMembership, everything's keyed off a user row in a table you define rather than a bunch of entries in membership tables that were out of your control. How SimpleMembership integrates with ASP.NET Membership Okay, enough sales pitch (and hopefully background) on why things have changed. How does this affect you? Let's start with a diagram to show the relationship (note: I've simplified by removing a few classes to show the important relationships): So SimpleMembershipProvider is an implementaiton of an ExtendedMembershipProvider, which inherits from MembershipProvider and adds some other account / OAuth related things. Here's what ExtendedMembershipProvider adds to MembershipProvider: The important thing to take away here is that a SimpleMembershipProvider is a MembershipProvider, but a MembershipProvider is not a SimpleMembershipProvider. This distinction is important in practice: you cannot use an existing MembershipProvider (including the Universal Providers found in System.Web.Providers) with an API that requires a SimpleMembershipProvider, including any of the calls in WebMatrix.WebData.WebSecurity or Microsoft.Web.WebPages.OAuth.OAuthWebSecurity. However, that's as far as it goes. Membership Providers still work if you're accessing them through the standard Membership API, and all of the core stuff  - including the AuthorizeAttribute, role enforcement, etc. - will work just fine and without any change. Let's look at how that affects you in terms of the new templates. Membership in the ASP.NET MVC 4 project templates ASP.NET MVC 4 offers six Project Templates: Empty - Really empty, just the assemblies, folder structure and a tiny bit of basic configuration. Basic - Like Empty, but with a bit of UI preconfigured (css / images / bundling). Internet - This has both a Home and Account controller and associated views. The Account Controller supports registration and login via either local accounts and via OAuth / OpenID providers. Intranet - Like the Internet template, but it's preconfigured for Windows Authentication. Mobile - This is preconfigured using jQuery Mobile and is intended for mobile-only sites. Web API - This is preconfigured for a service backend built on ASP.NET Web API. Out of these templates, only one (the Internet template) uses SimpleMembership. ASP.NET MVC 4 Basic template The Basic template has configuration in place to use ASP.NET Membership with the Universal Providers. You can see that configuration in the ASP.NET MVC 4 Basic template's web.config: <profile defaultProvider="DefaultProfileProvider"> <providers> <add name="DefaultProfileProvider" type="System.Web.Providers.DefaultProfileProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" applicationName="/" /> </providers> </profile> <membership defaultProvider="DefaultMembershipProvider"> <providers> <add name="DefaultMembershipProvider" type="System.Web.Providers.DefaultMembershipProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="false" maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10" applicationName="/" /> </providers> </membership> <roleManager defaultProvider="DefaultRoleProvider"> <providers> <add name="DefaultRoleProvider" type="System.Web.Providers.DefaultRoleProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" applicationName="/" /> </providers> </roleManager> <sessionState mode="InProc" customProvider="DefaultSessionProvider"> <providers> <add name="DefaultSessionProvider" type="System.Web.Providers.DefaultSessionStateProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" /> </providers> </sessionState> This means that it's business as usual for the Basic template as far as ASP.NET Membership works. ASP.NET MVC 4 Internet template The Internet template has a few things set up to bootstrap SimpleMembership: \Models\AccountModels.cs defines a basic user account and includes data annotations to define keys and such \Filters\InitializeSimpleMembershipAttribute.cs creates the membership database using the above model, then calls WebSecurity.InitializeDatabaseConnection which verifies that the underlying tables are in place and marks initialization as complete (for the application's lifetime) \Controllers\AccountController.cs makes heavy use of OAuthWebSecurity (for OAuth account registration / login / management) and WebSecurity. WebSecurity provides account management services for ASP.NET MVC (and Web Pages) WebSecurity can work with any ExtendedMembershipProvider. There's one in the box (SimpleMembershipProvider) but you can write your own. Since a standard MembershipProvider is not an ExtendedMembershipProvider, WebSecurity will throw exceptions if the default membership provider is a MembershipProvider rather than an ExtendedMembershipProvider. Practical example: Create a new ASP.NET MVC 4 application using the Internet application template Install the Microsoft ASP.NET Universal Providers for LocalDB NuGet package Run the application, click on Register, add a username and password, and click submit You'll get the following execption in AccountController.cs::Register: To call this method, the "Membership.Provider" property must be an instance of "ExtendedMembershipProvider". This occurs because the ASP.NET Universal Providers packages include a web.config transform that will update your web.config to add the Universal Provider configuration I showed in the Basic template example above. When WebSecurity tries to use the configured ASP.NET Membership Provider, it checks if it can be cast to an ExtendedMembershipProvider before doing anything else. So, what do you do? Options: If you want to use the new AccountController, you'll either need to use the SimpleMembershipProvider or another valid ExtendedMembershipProvider. This is pretty straightforward. If you want to use an existing ASP.NET Membership Provider in ASP.NET MVC 4, you can't use the new AccountController. You can do a few things: Replace  the AccountController.cs and AccountModels.cs in an ASP.NET MVC 4 Internet project with one from an ASP.NET MVC 3 application (you of course won't have OAuth support). Then, if you want, you can go through and remove other things that were built around SimpleMembership - the OAuth partial view, the NuGet packages (e.g. the DotNetOpenAuthAuth package, etc.) Use an ASP.NET MVC 4 Internet application template and add in a Universal Providers NuGet package. Then copy in the AccountController and AccountModel classes. Create an ASP.NET MVC 3 project and upgrade it to ASP.NET MVC 4 using the steps shown in the ASP.NET MVC 4 release notes. None of these are particularly elegant or simple. Maybe we (or just me?) can do something to make this simpler - perhaps a NuGet package. However, this should be an edge case - hopefully the cases where you'd need to create a new ASP.NET but use legacy ASP.NET Membership Providers should be pretty rare. Please let me (or, preferably the team) know if that's an incorrect assumption. Membership in the ASP.NET 4.5 project template ASP.NET 4.5 Web Forms took a different approach which builds off ASP.NET Membership. Instead of using the WebMatrix security assemblies, Web Forms uses Microsoft.AspNet.Membership.OpenAuth assembly. I'm no expert on this, but from a bit of time in ILSpy and Visual Studio's (very pretty) dependency graphs, this uses a Membership Adapter to save OAuth data into an EF managed database while still running on top of ASP.NET Membership. Note: There may be a way to use this in ASP.NET MVC 4, although it would probably take some plumbing work to hook it up. How does this fit in with Universal Providers (System.Web.Providers)? Just to summarize: Universal Providers are intended for cases where you have an existing ASP.NET Membership Provider and you want to use it with another SQL Server database backend (other than SQL Server). It doesn't require agents to handle expired session cleanup and other background tasks, it piggybacks these tasks on other calls. Universal Providers are not really, strictly speaking, universal - at least to my way of thinking. They only work with databases in the SQL Server family. Universal Providers do not work with Simple Membership. The Universal Providers packages include some web config transforms which you would normally want when you're using them. What about the Web Site Administration Tool? Visual Studio includes tooling to launch the Web Site Administration Tool (WSAT) to configure users and roles in your application. WSAT is built to work with ASP.NET Membership, and is not compatible with Simple Membership. There are two main options there: Use the WebSecurity and OAuthWebSecurity API to manage the users and roles Create a web admin using the above APIs Since SimpleMembership runs on top of your database, you can update your users as you would any other data - via EF or even in direct database edits (in development, of course)

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  • Improving Partitioned Table Join Performance

    - by Paul White
    The query optimizer does not always choose an optimal strategy when joining partitioned tables. This post looks at an example, showing how a manual rewrite of the query can almost double performance, while reducing the memory grant to almost nothing. Test Data The two tables in this example use a common partitioning partition scheme. The partition function uses 41 equal-size partitions: CREATE PARTITION FUNCTION PFT (integer) AS RANGE RIGHT FOR VALUES ( 125000, 250000, 375000, 500000, 625000, 750000, 875000, 1000000, 1125000, 1250000, 1375000, 1500000, 1625000, 1750000, 1875000, 2000000, 2125000, 2250000, 2375000, 2500000, 2625000, 2750000, 2875000, 3000000, 3125000, 3250000, 3375000, 3500000, 3625000, 3750000, 3875000, 4000000, 4125000, 4250000, 4375000, 4500000, 4625000, 4750000, 4875000, 5000000 ); GO CREATE PARTITION SCHEME PST AS PARTITION PFT ALL TO ([PRIMARY]); There two tables are: CREATE TABLE dbo.T1 ( TID integer NOT NULL IDENTITY(0,1), Column1 integer NOT NULL, Padding binary(100) NOT NULL DEFAULT 0x,   CONSTRAINT PK_T1 PRIMARY KEY CLUSTERED (TID) ON PST (TID) );   CREATE TABLE dbo.T2 ( TID integer NOT NULL, Column1 integer NOT NULL, Padding binary(100) NOT NULL DEFAULT 0x,   CONSTRAINT PK_T2 PRIMARY KEY CLUSTERED (TID, Column1) ON PST (TID) ); The next script loads 5 million rows into T1 with a pseudo-random value between 1 and 5 for Column1. The table is partitioned on the IDENTITY column TID: INSERT dbo.T1 WITH (TABLOCKX) (Column1) SELECT (ABS(CHECKSUM(NEWID())) % 5) + 1 FROM dbo.Numbers AS N WHERE n BETWEEN 1 AND 5000000; In case you don’t already have an auxiliary table of numbers lying around, here’s a script to create one with 10 million rows: CREATE TABLE dbo.Numbers (n bigint PRIMARY KEY);   WITH L0 AS(SELECT 1 AS c UNION ALL SELECT 1), L1 AS(SELECT 1 AS c FROM L0 AS A CROSS JOIN L0 AS B), L2 AS(SELECT 1 AS c FROM L1 AS A CROSS JOIN L1 AS B), L3 AS(SELECT 1 AS c FROM L2 AS A CROSS JOIN L2 AS B), L4 AS(SELECT 1 AS c FROM L3 AS A CROSS JOIN L3 AS B), L5 AS(SELECT 1 AS c FROM L4 AS A CROSS JOIN L4 AS B), Nums AS(SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS n FROM L5) INSERT dbo.Numbers WITH (TABLOCKX) SELECT TOP (10000000) n FROM Nums ORDER BY n OPTION (MAXDOP 1); Table T1 contains data like this: Next we load data into table T2. The relationship between the two tables is that table 2 contains ‘n’ rows for each row in table 1, where ‘n’ is determined by the value in Column1 of table T1. There is nothing particularly special about the data or distribution, by the way. INSERT dbo.T2 WITH (TABLOCKX) (TID, Column1) SELECT T.TID, N.n FROM dbo.T1 AS T JOIN dbo.Numbers AS N ON N.n >= 1 AND N.n <= T.Column1; Table T2 ends up containing about 15 million rows: The primary key for table T2 is a combination of TID and Column1. The data is partitioned according to the value in column TID alone. Partition Distribution The following query shows the number of rows in each partition of table T1: SELECT PartitionID = CA1.P, NumRows = COUNT_BIG(*) FROM dbo.T1 AS T CROSS APPLY (VALUES ($PARTITION.PFT(TID))) AS CA1 (P) GROUP BY CA1.P ORDER BY CA1.P; There are 40 partitions containing 125,000 rows (40 * 125k = 5m rows). The rightmost partition remains empty. The next query shows the distribution for table 2: SELECT PartitionID = CA1.P, NumRows = COUNT_BIG(*) FROM dbo.T2 AS T CROSS APPLY (VALUES ($PARTITION.PFT(TID))) AS CA1 (P) GROUP BY CA1.P ORDER BY CA1.P; There are roughly 375,000 rows in each partition (the rightmost partition is also empty): Ok, that’s the test data done. Test Query and Execution Plan The task is to count the rows resulting from joining tables 1 and 2 on the TID column: SET STATISTICS IO ON; DECLARE @s datetime2 = SYSUTCDATETIME();   SELECT COUNT_BIG(*) FROM dbo.T1 AS T1 JOIN dbo.T2 AS T2 ON T2.TID = T1.TID;   SELECT DATEDIFF(Millisecond, @s, SYSUTCDATETIME()); SET STATISTICS IO OFF; The optimizer chooses a plan using parallel hash join, and partial aggregation: The Plan Explorer plan tree view shows accurate cardinality estimates and an even distribution of rows across threads (click to enlarge the image): With a warm data cache, the STATISTICS IO output shows that no physical I/O was needed, and all 41 partitions were touched: Running the query without actual execution plan or STATISTICS IO information for maximum performance, the query returns in around 2600ms. Execution Plan Analysis The first step toward improving on the execution plan produced by the query optimizer is to understand how it works, at least in outline. The two parallel Clustered Index Scans use multiple threads to read rows from tables T1 and T2. Parallel scan uses a demand-based scheme where threads are given page(s) to scan from the table as needed. This arrangement has certain important advantages, but does result in an unpredictable distribution of rows amongst threads. The point is that multiple threads cooperate to scan the whole table, but it is impossible to predict which rows end up on which threads. For correct results from the parallel hash join, the execution plan has to ensure that rows from T1 and T2 that might join are processed on the same thread. For example, if a row from T1 with join key value ‘1234’ is placed in thread 5’s hash table, the execution plan must guarantee that any rows from T2 that also have join key value ‘1234’ probe thread 5’s hash table for matches. The way this guarantee is enforced in this parallel hash join plan is by repartitioning rows to threads after each parallel scan. The two repartitioning exchanges route rows to threads using a hash function over the hash join keys. The two repartitioning exchanges use the same hash function so rows from T1 and T2 with the same join key must end up on the same hash join thread. Expensive Exchanges This business of repartitioning rows between threads can be very expensive, especially if a large number of rows is involved. The execution plan selected by the optimizer moves 5 million rows through one repartitioning exchange and around 15 million across the other. As a first step toward removing these exchanges, consider the execution plan selected by the optimizer if we join just one partition from each table, disallowing parallelism: SELECT COUNT_BIG(*) FROM dbo.T1 AS T1 JOIN dbo.T2 AS T2 ON T2.TID = T1.TID WHERE $PARTITION.PFT(T1.TID) = 1 AND $PARTITION.PFT(T2.TID) = 1 OPTION (MAXDOP 1); The optimizer has chosen a (one-to-many) merge join instead of a hash join. The single-partition query completes in around 100ms. If everything scaled linearly, we would expect that extending this strategy to all 40 populated partitions would result in an execution time around 4000ms. Using parallelism could reduce that further, perhaps to be competitive with the parallel hash join chosen by the optimizer. This raises a question. If the most efficient way to join one partition from each of the tables is to use a merge join, why does the optimizer not choose a merge join for the full query? Forcing a Merge Join Let’s force the optimizer to use a merge join on the test query using a hint: SELECT COUNT_BIG(*) FROM dbo.T1 AS T1 JOIN dbo.T2 AS T2 ON T2.TID = T1.TID OPTION (MERGE JOIN); This is the execution plan selected by the optimizer: This plan results in the same number of logical reads reported previously, but instead of 2600ms the query takes 5000ms. The natural explanation for this drop in performance is that the merge join plan is only using a single thread, whereas the parallel hash join plan could use multiple threads. Parallel Merge Join We can get a parallel merge join plan using the same query hint as before, and adding trace flag 8649: SELECT COUNT_BIG(*) FROM dbo.T1 AS T1 JOIN dbo.T2 AS T2 ON T2.TID = T1.TID OPTION (MERGE JOIN, QUERYTRACEON 8649); The execution plan is: This looks promising. It uses a similar strategy to distribute work across threads as seen for the parallel hash join. In practice though, performance is disappointing. On a typical run, the parallel merge plan runs for around 8400ms; slower than the single-threaded merge join plan (5000ms) and much worse than the 2600ms for the parallel hash join. We seem to be going backwards! The logical reads for the parallel merge are still exactly the same as before, with no physical IOs. The cardinality estimates and thread distribution are also still very good (click to enlarge): A big clue to the reason for the poor performance is shown in the wait statistics (captured by Plan Explorer Pro): CXPACKET waits require careful interpretation, and are most often benign, but in this case excessive waiting occurs at the repartitioning exchanges. Unlike the parallel hash join, the repartitioning exchanges in this plan are order-preserving ‘merging’ exchanges (because merge join requires ordered inputs): Parallelism works best when threads can just grab any available unit of work and get on with processing it. Preserving order introduces inter-thread dependencies that can easily lead to significant waits occurring. In extreme cases, these dependencies can result in an intra-query deadlock, though the details of that will have to wait for another time to explore in detail. The potential for waits and deadlocks leads the query optimizer to cost parallel merge join relatively highly, especially as the degree of parallelism (DOP) increases. This high costing resulted in the optimizer choosing a serial merge join rather than parallel in this case. The test results certainly confirm its reasoning. Collocated Joins In SQL Server 2008 and later, the optimizer has another available strategy when joining tables that share a common partition scheme. This strategy is a collocated join, also known as as a per-partition join. It can be applied in both serial and parallel execution plans, though it is limited to 2-way joins in the current optimizer. Whether the optimizer chooses a collocated join or not depends on cost estimation. The primary benefits of a collocated join are that it eliminates an exchange and requires less memory, as we will see next. Costing and Plan Selection The query optimizer did consider a collocated join for our original query, but it was rejected on cost grounds. The parallel hash join with repartitioning exchanges appeared to be a cheaper option. There is no query hint to force a collocated join, so we have to mess with the costing framework to produce one for our test query. Pretending that IOs cost 50 times more than usual is enough to convince the optimizer to use collocated join with our test query: -- Pretend IOs are 50x cost temporarily DBCC SETIOWEIGHT(50);   -- Co-located hash join SELECT COUNT_BIG(*) FROM dbo.T1 AS T1 JOIN dbo.T2 AS T2 ON T2.TID = T1.TID OPTION (RECOMPILE);   -- Reset IO costing DBCC SETIOWEIGHT(1); Collocated Join Plan The estimated execution plan for the collocated join is: The Constant Scan contains one row for each partition of the shared partitioning scheme, from 1 to 41. The hash repartitioning exchanges seen previously are replaced by a single Distribute Streams exchange using Demand partitioning. Demand partitioning means that the next partition id is given to the next parallel thread that asks for one. My test machine has eight logical processors, and all are available for SQL Server to use. As a result, there are eight threads in the single parallel branch in this plan, each processing one partition from each table at a time. Once a thread finishes processing a partition, it grabs a new partition number from the Distribute Streams exchange…and so on until all partitions have been processed. It is important to understand that the parallel scans in this plan are different from the parallel hash join plan. Although the scans have the same parallelism icon, tables T1 and T2 are not being co-operatively scanned by multiple threads in the same way. Each thread reads a single partition of T1 and performs a hash match join with the same partition from table T2. The properties of the two Clustered Index Scans show a Seek Predicate (unusual for a scan!) limiting the rows to a single partition: The crucial point is that the join between T1 and T2 is on TID, and TID is the partitioning column for both tables. A thread that processes partition ‘n’ is guaranteed to see all rows that can possibly join on TID for that partition. In addition, no other thread will see rows from that partition, so this removes the need for repartitioning exchanges. CPU and Memory Efficiency Improvements The collocated join has removed two expensive repartitioning exchanges and added a single exchange processing 41 rows (one for each partition id). Remember, the parallel hash join plan exchanges had to process 5 million and 15 million rows. The amount of processor time spent on exchanges will be much lower in the collocated join plan. In addition, the collocated join plan has a maximum of 8 threads processing single partitions at any one time. The 41 partitions will all be processed eventually, but a new partition is not started until a thread asks for it. Threads can reuse hash table memory for the new partition. The parallel hash join plan also had 8 hash tables, but with all 5,000,000 build rows loaded at the same time. The collocated plan needs memory for only 8 * 125,000 = 1,000,000 rows at any one time. Collocated Hash Join Performance The collated join plan has disappointing performance in this case. The query runs for around 25,300ms despite the same IO statistics as usual. This is much the worst result so far, so what went wrong? It turns out that cardinality estimation for the single partition scans of table T1 is slightly low. The properties of the Clustered Index Scan of T1 (graphic immediately above) show the estimation was for 121,951 rows. This is a small shortfall compared with the 125,000 rows actually encountered, but it was enough to cause the hash join to spill to physical tempdb: A level 1 spill doesn’t sound too bad, until you realize that the spill to tempdb probably occurs for each of the 41 partitions. As a side note, the cardinality estimation error is a little surprising because the system tables accurately show there are 125,000 rows in every partition of T1. Unfortunately, the optimizer uses regular column and index statistics to derive cardinality estimates here rather than system table information (e.g. sys.partitions). Collocated Merge Join We will never know how well the collocated parallel hash join plan might have worked without the cardinality estimation error (and the resulting 41 spills to tempdb) but we do know: Merge join does not require a memory grant; and Merge join was the optimizer’s preferred join option for a single partition join Putting this all together, what we would really like to see is the same collocated join strategy, but using merge join instead of hash join. Unfortunately, the current query optimizer cannot produce a collocated merge join; it only knows how to do collocated hash join. So where does this leave us? CROSS APPLY sys.partitions We can try to write our own collocated join query. We can use sys.partitions to find the partition numbers, and CROSS APPLY to get a count per partition, with a final step to sum the partial counts. The following query implements this idea: SELECT row_count = SUM(Subtotals.cnt) FROM ( -- Partition numbers SELECT p.partition_number FROM sys.partitions AS p WHERE p.[object_id] = OBJECT_ID(N'T1', N'U') AND p.index_id = 1 ) AS P CROSS APPLY ( -- Count per collocated join SELECT cnt = COUNT_BIG(*) FROM dbo.T1 AS T1 JOIN dbo.T2 AS T2 ON T2.TID = T1.TID WHERE $PARTITION.PFT(T1.TID) = p.partition_number AND $PARTITION.PFT(T2.TID) = p.partition_number ) AS SubTotals; The estimated plan is: The cardinality estimates aren’t all that good here, especially the estimate for the scan of the system table underlying the sys.partitions view. Nevertheless, the plan shape is heading toward where we would like to be. Each partition number from the system table results in a per-partition scan of T1 and T2, a one-to-many Merge Join, and a Stream Aggregate to compute the partial counts. The final Stream Aggregate just sums the partial counts. Execution time for this query is around 3,500ms, with the same IO statistics as always. This compares favourably with 5,000ms for the serial plan produced by the optimizer with the OPTION (MERGE JOIN) hint. This is another case of the sum of the parts being less than the whole – summing 41 partial counts from 41 single-partition merge joins is faster than a single merge join and count over all partitions. Even so, this single-threaded collocated merge join is not as quick as the original parallel hash join plan, which executed in 2,600ms. On the positive side, our collocated merge join uses only one logical processor and requires no memory grant. The parallel hash join plan used 16 threads and reserved 569 MB of memory:   Using a Temporary Table Our collocated merge join plan should benefit from parallelism. The reason parallelism is not being used is that the query references a system table. We can work around that by writing the partition numbers to a temporary table (or table variable): SET STATISTICS IO ON; DECLARE @s datetime2 = SYSUTCDATETIME();   CREATE TABLE #P ( partition_number integer PRIMARY KEY);   INSERT #P (partition_number) SELECT p.partition_number FROM sys.partitions AS p WHERE p.[object_id] = OBJECT_ID(N'T1', N'U') AND p.index_id = 1;   SELECT row_count = SUM(Subtotals.cnt) FROM #P AS p CROSS APPLY ( SELECT cnt = COUNT_BIG(*) FROM dbo.T1 AS T1 JOIN dbo.T2 AS T2 ON T2.TID = T1.TID WHERE $PARTITION.PFT(T1.TID) = p.partition_number AND $PARTITION.PFT(T2.TID) = p.partition_number ) AS SubTotals;   DROP TABLE #P;   SELECT DATEDIFF(Millisecond, @s, SYSUTCDATETIME()); SET STATISTICS IO OFF; Using the temporary table adds a few logical reads, but the overall execution time is still around 3500ms, indistinguishable from the same query without the temporary table. The problem is that the query optimizer still doesn’t choose a parallel plan for this query, though the removal of the system table reference means that it could if it chose to: In fact the optimizer did enter the parallel plan phase of query optimization (running search 1 for a second time): Unfortunately, the parallel plan found seemed to be more expensive than the serial plan. This is a crazy result, caused by the optimizer’s cost model not reducing operator CPU costs on the inner side of a nested loops join. Don’t get me started on that, we’ll be here all night. In this plan, everything expensive happens on the inner side of a nested loops join. Without a CPU cost reduction to compensate for the added cost of exchange operators, candidate parallel plans always look more expensive to the optimizer than the equivalent serial plan. Parallel Collocated Merge Join We can produce the desired parallel plan using trace flag 8649 again: SELECT row_count = SUM(Subtotals.cnt) FROM #P AS p CROSS APPLY ( SELECT cnt = COUNT_BIG(*) FROM dbo.T1 AS T1 JOIN dbo.T2 AS T2 ON T2.TID = T1.TID WHERE $PARTITION.PFT(T1.TID) = p.partition_number AND $PARTITION.PFT(T2.TID) = p.partition_number ) AS SubTotals OPTION (QUERYTRACEON 8649); The actual execution plan is: One difference between this plan and the collocated hash join plan is that a Repartition Streams exchange operator is used instead of Distribute Streams. The effect is similar, though not quite identical. The Repartition uses round-robin partitioning, meaning the next partition id is pushed to the next thread in sequence. The Distribute Streams exchange seen earlier used Demand partitioning, meaning the next partition id is pulled across the exchange by the next thread that is ready for more work. There are subtle performance implications for each partitioning option, but going into that would again take us too far off the main point of this post. Performance The important thing is the performance of this parallel collocated merge join – just 1350ms on a typical run. The list below shows all the alternatives from this post (all timings include creation, population, and deletion of the temporary table where appropriate) from quickest to slowest: Collocated parallel merge join: 1350ms Parallel hash join: 2600ms Collocated serial merge join: 3500ms Serial merge join: 5000ms Parallel merge join: 8400ms Collated parallel hash join: 25,300ms (hash spill per partition) The parallel collocated merge join requires no memory grant (aside from a paltry 1.2MB used for exchange buffers). This plan uses 16 threads at DOP 8; but 8 of those are (rather pointlessly) allocated to the parallel scan of the temporary table. These are minor concerns, but it turns out there is a way to address them if it bothers you. Parallel Collocated Merge Join with Demand Partitioning This final tweak replaces the temporary table with a hard-coded list of partition ids (dynamic SQL could be used to generate this query from sys.partitions): SELECT row_count = SUM(Subtotals.cnt) FROM ( VALUES (1),(2),(3),(4),(5),(6),(7),(8),(9),(10), (11),(12),(13),(14),(15),(16),(17),(18),(19),(20), (21),(22),(23),(24),(25),(26),(27),(28),(29),(30), (31),(32),(33),(34),(35),(36),(37),(38),(39),(40),(41) ) AS P (partition_number) CROSS APPLY ( SELECT cnt = COUNT_BIG(*) FROM dbo.T1 AS T1 JOIN dbo.T2 AS T2 ON T2.TID = T1.TID WHERE $PARTITION.PFT(T1.TID) = p.partition_number AND $PARTITION.PFT(T2.TID) = p.partition_number ) AS SubTotals OPTION (QUERYTRACEON 8649); The actual execution plan is: The parallel collocated hash join plan is reproduced below for comparison: The manual rewrite has another advantage that has not been mentioned so far: the partial counts (per partition) can be computed earlier than the partial counts (per thread) in the optimizer’s collocated join plan. The earlier aggregation is performed by the extra Stream Aggregate under the nested loops join. The performance of the parallel collocated merge join is unchanged at around 1350ms. Final Words It is a shame that the current query optimizer does not consider a collocated merge join (Connect item closed as Won’t Fix). The example used in this post showed an improvement in execution time from 2600ms to 1350ms using a modestly-sized data set and limited parallelism. In addition, the memory requirement for the query was almost completely eliminated  – down from 569MB to 1.2MB. The problem with the parallel hash join selected by the optimizer is that it attempts to process the full data set all at once (albeit using eight threads). It requires a large memory grant to hold all 5 million rows from table T1 across the eight hash tables, and does not take advantage of the divide-and-conquer opportunity offered by the common partitioning. The great thing about the collocated join strategies is that each parallel thread works on a single partition from both tables, reading rows, performing the join, and computing a per-partition subtotal, before moving on to a new partition. From a thread’s point of view… If you have trouble visualizing what is happening from just looking at the parallel collocated merge join execution plan, let’s look at it again, but from the point of view of just one thread operating between the two Parallelism (exchange) operators. Our thread picks up a single partition id from the Distribute Streams exchange, and starts a merge join using ordered rows from partition 1 of table T1 and partition 1 of table T2. By definition, this is all happening on a single thread. As rows join, they are added to a (per-partition) count in the Stream Aggregate immediately above the Merge Join. Eventually, either T1 (partition 1) or T2 (partition 1) runs out of rows and the merge join stops. The per-partition count from the aggregate passes on through the Nested Loops join to another Stream Aggregate, which is maintaining a per-thread subtotal. Our same thread now picks up a new partition id from the exchange (say it gets id 9 this time). The count in the per-partition aggregate is reset to zero, and the processing of partition 9 of both tables proceeds just as it did for partition 1, and on the same thread. Each thread picks up a single partition id and processes all the data for that partition, completely independently from other threads working on other partitions. One thread might eventually process partitions (1, 9, 17, 25, 33, 41) while another is concurrently processing partitions (2, 10, 18, 26, 34) and so on for the other six threads at DOP 8. The point is that all 8 threads can execute independently and concurrently, continuing to process new partitions until the wider job (of which the thread has no knowledge!) is done. This divide-and-conquer technique can be much more efficient than simply splitting the entire workload across eight threads all at once. Related Reading Understanding and Using Parallelism in SQL Server Parallel Execution Plans Suck © 2013 Paul White – All Rights Reserved Twitter: @SQL_Kiwi

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  • What causes this org.hibernate.MappingException?

    - by stacker
    I'm trying to configure an ejb3 sample application, it's entities where mapped to postgres now I want the app run on Jboss4.3 and Informix using JPA. If the DDL creation <property name="hibernate.hbm2ddl.auto" value="create"/> is active this error appears > WARN [ServiceController] Problem > starting service > persistence.units:ear=weblog.ear,jar=weblog.jar,unitName=weblog > javax.persistence.PersistenceException: > [PersistenceUnit: weblog] Unable to > build EntityManagerFactory > at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:677) > at org.hibernate.ejb.HibernatePersistence.createContainerEntityManagerFactory(HibernatePersistence.java:132) > at org.jboss.ejb3.entity.PersistenceUnitDeployment.start(PersistenceUnitDeployment.java:246) followed by Caused by: org.hibernate.MappingException: No Dialect mapping for JDBC type: 2005 at org.hibernate.dialect.TypeNames.get(TypeNames.java:56) at org.hibernate.dialect.TypeNames.get(TypeNames.java:81) at org.hibernate.dialect.Dialect.getTypeName(Dialect.java:291) at org.hibernate.mapping.Column.getSqlType(Column.java:182) at org.hibernate.mapping.Table.sqlCreateString(Table.java:394) at org.hibernate.cfg.Configuration.generateSchemaCreationScript(Configuration.java:854) at org.hibernate.tool.hbm2ddl.SchemaExport.<init>(SchemaExport.java:74) at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:311) at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1300) at org.hibernate.cfg.AnnotationConfiguration.buildSessionFactory(AnnotationConfiguration.java:874) at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:669) What does JDBC type: 2005 mean? Any idea how I can track down the entity/column causes the problem? Thanks

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  • JavaScriptSerializer().Serialize(Entity Framework object)

    - by loviji
    May be, it is not so problematic for you. but i'm trying first time with json serialization. and also read other articles in stackowerflow. I have created Entity Framework data model. then by method get all data from object: private uqsEntities _db = new uqsEntities(); //get all data from table sysMainTableColumns where tableName=paramtableName public List<sysMainTableColumns> getDataAboutMainTable(string tableName) { return (from column in _db.sysMainTableColumns where column.TableName==tableName select column).ToList(); } my webservice: public string getDataAboutMainTable() { penta.DAC.Tables dictTable = new penta.DAC.Tables(); var result = dictTable.getDataAboutMainTable("1"); return new JavaScriptSerializer().Serialize(result); } and jQuery ajax method $('#loadData').click(function() { $.ajax({ type: "POST", url: "WS/ConstructorWS.asmx/getDataAboutMainTable", data: "{}", contentType: "application/json; charset=utf-8", dataType: "json", success: function(msg) { $("#jsonResponse").html(msg); var data = eval("(" + msg + ")"); //do something with data }, error: function(msg) { } }); }); problem with data, code fails there. and i think i'm not use JavaScriptSerializer().Serialize() method very well. Please, tell me, what a big mistake I made in C# code?

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  • WPF Toolkit DataGridCell Style DataTrigger

    - by KrisTrip
    I am trying to change the color of a cell to Yellow if the value has been updated in the DataGrid. My XAML: <toolkit:DataGrid x:Name="TheGrid" ItemsSource="{Binding}" IsReadOnly="False" CanUserAddRows="False" CanUserResizeRows="False" AutoGenerateColumns="False" CanUserSortColumns="False" SelectionUnit="CellOrRowHeader" EnableColumnVirtualization="True" VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto"> <toolkit:DataGrid.CellStyle> <Style TargetType="{x:Type toolkit:DataGridCell}"> <Style.Triggers> <DataTrigger Binding="{Binding IsDirty}" Value="True"> <Setter Property="Background" Value="Yellow"/> </DataTrigger> </Style.Triggers> </Style> </toolkit:DataGrid.CellStyle> </toolkit:DataGrid> The grid is bound to a List of arrays (displaying a table of values kind of like excel would). Each value in the array is a custom object that contains an IsDirty dependency property. The IsDirty property gets set when the value is changed. When i run this: change a value in column 1 = whole row goes yellow change a value in any other column = nothing happens I want only the changed cell to go yellow no matter what column its in. Do you see anything wrong with my XAML?

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  • Listview of items from a object selected in another listview

    - by Ingó Vals
    Ok the title maybe a little confusing. I have a database with the table Companies wich has one-to-many relotionship with another table Divisions ( so each company can have many divisions ) and division will have many employees. I have a ListView of the companies. What I wan't is that when I choose a company from the ListView another ListView of divisions within that company appears below it. Then I pick a division and another listview of employees within that division appaers below that. You get the picture. Is there anyway to do this mostly inside the XAML code declaritively (sp?). I'm using linq so the Company entity objects have a property named Division wich if I understand linq correctly should include Division objects of the divisions connected to the company. So after getting all the companies and putting them as a itemsource to CompanyListView this is where I currently am. <ListView x:Name="CompanyListView" DisplayMemberPath="CompanyName" Grid.Row="0" Grid.Column="0" /> <ListView DataContext="{Binding ElementName=CompanyListView, Path=SelectedItem}" DisplayMemberPath="Division.DivisionName" Grid.Row="1" Grid.Column="0" /> I know I'm way off but I was hoping by putting something specific in the DataContext and DisplayMemberPath I could get this to work. If not then I have to capture the Id of the company I guess and capture a select event or something. Another issue but related is the in the seconde column besides the lisview I wan't to have a details/edit view for the selected item. So when only a company is selected details about that will appear then when a division under the company is picked It will go there instead, any ideas?

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  • How to bind collection to WPF:DataGridComboBoxColumn

    - by everwicked
    Admittedly I am new to WPF but I have looked and looked and can't find a solution to this problem. I have a simple object like: class Item { .... public String Measure { get; set; } public String[] Measures {get; } } Which I am trying to bind to a DataGrid with two text columns and a combo box column. For the combo box column, propery Measure is the current selection and Measures the possible values. My XAML is: <DataGridComboBoxColumn Header="Measure" Width="Auto" SelectedItemBinding="{Binding Path=Measure}" ItemsSource="{Binding Path=Measures}"/> </DataGrid.Columns> </DataGrid> The text column are displayed just fine but the combobox is not - the values are not displayed at all. The binding error is : ¨System.Windows.Data Error: 2 : Cannot find governing FrameworkElement or FrameworkContentElement for target element. BindingExpression:Path=Measures; DataItem=null; target element is 'DataGridComboBoxColumn' (HashCode=11497055); target property is 'ItemsSource' (type 'IEnumerable') How do I fix this??? Thanks

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  • Java RegEx API "Look-behind group does not have an obvious maximum length near index ..."

    - by Foo Inc
    Hello, I'm on to some SQL where clause parsing and designed a working RegEx to find a column outside string literals using "Rad Software Regular Expression Desginer" which is using the .NET API. To make sure the designed RegEx works with Java too, I tested it by using the API of course (1.5 and 1.6). But guess what, it won't work. I got the message "Look-behind group does not have an obvious maximum length near index 28". The string that I'm trying to get parsed is Column_1='test''the''stuff''all''day''long' AND Column_2='000' AND TheVeryColumnIWantToFind = 'Column_1=''test''''the''''stuff''''all''''day''''long'' AND Column_2=''000'' AND TheVeryColumnIWantToFind = '' TheVeryColumnIWantToFind = '' AND (Column_3 is null or Column_3 = ''Not interesting'') AND ''1'' = ''1''' AND (Column_3 is null or Column_3 = 'Still not interesting') AND '1' = '1' As you may have guessed, I tried to create some kind of worst case to ensure the RegEx won't fail on more complicated SQL where clauses. The RegEx itself looks like this (?i:(?<!=\s*'(?:[^']|(?:''))*)((?<=\s*)TheVeryColumnIWantToFind(?=(?:\s+|=)))) I'm not sure if there is a more elegant RegEx (there'll most likely be one), but that's not important right now as it does the trick. To explain the RegEx in a few words: If it finds the column I'm after, it does a negative look-behind to figure out if the column name is used in a string literal. If so, it won't match. If not, it'll match. Back to the question. As I mentioned before, it won't work with Java. What will work and result in what I want? I found out, that Java does not seem to support unlimited look-behinds but still I couldn't get it to work. Isn't it right that a look-behind is always putting a limit up on itself from the search offset to the current search position? So it would result in something like "position - offset"?

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  • How do I add PHP support to Apache 2 without breaking my current installation?

    - by Hobhouse
    I run Apache 2 with WSGI (for a Django-app) on a Ubuntu box. I want to use Nagios for server monitoring, and for this purpose it seems I have to add PHP support to Apache. When I installed Apache 2, I did this: apt-get install apache2 apache2.2-common apache2-mpm-worker apache2-threaded-dev libapache2-mod-wsgi python-dev Available modules for apache2 are these: /etc/apache2/mods-available$ ls actions.conf authn_default.load cache.load deflate.conf filter.load mime.conf proxy_ftp.load suexec.load actions.load authn_file.load cern_meta.load deflate.load headers.load mime.load proxy_http.load unique_id.load alias.conf authnz_ldap.load cgi.load dir.conf ident.load mime_magic.conf rewrite.load userdir.conf alias.load authz_dbm.load cgid.conf dir.load imagemap.load mime_magic.load setenvif.conf userdir.load asis.load authz_default.load cgid.load disk_cache.conf include.load negotiation.conf setenvif.load usertrack.load auth_basic.load authz_groupfile.load charset_lite.load disk_cache.load info.conf negotiation.load speling.load version.load auth_digest.load authz_host.load dav.load dump_io.load info.load proxy.conf ssl.conf vhost_alias.load authn_alias.load authz_owner.load dav_fs.conf env.load ldap.load proxy.load ssl.load wsgi.conf authn_anon.load authz_user.load dav_fs.load expires.load log_forensic.load proxy_ajp.load status.conf wsgi.load authn_dbd.load autoindex.conf dav_lock.load ext_filter.load mem_cache.conf proxy_balancer.load status.load authn_dbm.load autoindex.load dbd.load file_cache.load mem_cache.load proxy_connect.load substitute.load What is the best way for me to add PHP support to Apache 2 without breaking my current installation and configuration?

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  • Google Apps Script - Sending Google Spreadsheet Row to Email

    - by AME
    Hi I am trying to write a script using Google Apps Script (Javascript) for a Google spreadsheet. I am trying to do the same thing that is shown in this tutorial [http://www.google.com/google-d-s/scripts/sending_emails.html][1], but each row in my spreadsheet has 24 columns. I would like to send out the contents of each row as an email. Here is the code as I am trying to use: function sendEmails() { var sheet = SpreadsheetApp.getActiveSheet(); var dataRange = sheet.getRange("A2:X31") // Fetch values for each row in the Range. var data = dataRange.getValues(); for (i in data) { var row = data[i]; var i = i + 1; var emailAddress = row[0]; // First column var message = row[1]; // Second column var subject = "Sending emails from a Spreadsheet"; MailApp.sendEmail(emailAddress, subject, message); } }? The result is an email with the contents in the "B" column only. Can someone help me change this code to get all of the contents in each row (columns A-X). Thanks,

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