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• Max Degree of Parallelism Server-Side Setting

  - by Tara Kizer

  Recently I opened a case with Microsoft PSS to help us through a severe performance problem on a new system.  As part of that case, the PSS engineer checked our “max degree of parallelism” server-side setting.  It is our standard to use 4 on our production systems that have 16 CPUs (2 sockets, quad-core, hyper-threaded).  The PSS engineer had me run the below query to get Microsoft’s recommended value of “max degree of parallelism” server-side setting for our 16-CPU system: select case when cpu_count / hyperthread_ratio > 8 then 8 else cpu_count / hyperthread_ratio end as optimal_maxdop_setting from sys.dm_os_sys_info; The query returned 2.  I made the change using sp_configure, and it did not resolve our issue.  We have decided to leave it in place for now.   Do you agree with this query?  What are your thoughts on this? If you decide to change your setting to reflect the output of this query, please test it first to ensure there are no negative side effects.

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• Secret of SQL Trace Duration Column

  - by Dan Guzman

  Why would a trace of long-running queries not show all queries that exceeded the specified duration filter?  We have a server-side SQL Trace that includes RPC:Completed and SQL:BatchCompleted events with a filter on Duration >= 100000.  Nearly all of the queries on this busy OLTP server run in under this 100 millisecond threshold so any that appear in the trace are candidates for root cause analysis and/or performance tuning opportunities. After an application experienced query timeouts, the DBA looked at the trace data to corroborate the problem.  Surprisingly, he found no long-running queries in the trace from the application that experienced the timeouts even though the application’s error log clearly showed detail of the problem (query text, duration, start time, etc.).  The trace did show, however, that there were hundreds of other long-running queries from different applications during the problem timeframe.  We later determined those queries were blocked by a large UPDATE query against a critical table that was inadvertently run during this busy period. So why didn’t the trace include all of the long-running queries?  The reason is because the SQL Trace event duration doesn’t include the time a request was queued while awaiting a worker thread.  Remember that the server was under considerable stress at the time due to the severe blocking episode.  Most of the worker threads were in use by blocked queries and new requests were queued awaiting a worker to free up (a DMV query on the DAC connection will show this queuing: “SELECT scheduler_id, work_queue_count FROM sys.dm_os_schedulers;”).  Technically, those queued requests had not started.  As worker threads became available, queries were dequeued and completed quickly.  These weren’t included in the trace because the duration was under the 100ms duration filter.  The duration reflected the time it took to actually run the query but didn’t include the time queued waiting for a worker thread. The important point here is that duration is not end-to-end response time.  Duration of RPC:Completed and SQL:BatchCompleted events doesn’t include time before a worker thread is assigned nor does it include the time required to return the last result buffer to the client.  In other words, duration only includes time after the worker thread is assigned until the last buffer is filled.  But be aware that duration does include the time need to return intermediate result set buffers back to the client, which is a factor when large query results are returned.  Clients that are slow in consuming results sets can increase the duration value reported by the trace “completed” events.

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• Execution plan different on two different Sql Servers

  - by Lieven Cardoen

  On our sql server, a query takes 20 ms. If I look at the execution plan, parallelism is used, hash match, Bitmap create, ... a lot of images with two arrows pointing to the left. On sql server of a customer where our product runs, the same query takes 2500 ms. If I look at their execution plan, no parallelism or any of the things with arrows are used... I've been searching for a couple of days no why the query runs so much slower on their sql server. Is parallelism and all of the other things something that can be configured on their sql server? And how to you configure that? What are the dangers of using parallelism? Another strange thing is that on our server, the query needs some 1200 reads and 0 writes. On their sql server it needs 1.5 million reads and some 1500 writes. Why these writes when a read query is done?

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• alternative to environment variables

  - by tonyl7126

  The amount of servers and the complexity of our application is growing and we now have servers in different regions (hosted on AWS). Certain database operations require low latency so we have stuck a database in each region (which is basically a user cache) to keep the network latency low. The way the application server currently knows which user cache/database to make its call to depends on an environemnt variable set in it. This has been working fine, but it seems hacky and not optimal. Is there any way for this to be done automatically? I was considering using a package like fping and pinging each database when the app server reloads (or caching it the first time) and using the corresponding latencies to decide which database has the lowest latency for each app server. Not sure if this is the best idea though.

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• SQL Server 2008 Optimization

  - by hgulyan

  I've learned today, if you append to your query OPTION (MAXDOP 0) your query will run on multiple processors and if it's huge query, query will perform faster. I know general guidelines on query optimizations (using indexes, selecting only needed fields etc.), my question is about SQL Server optimization. Maybe changing some options in configurations or anything else. What guidelines are there for SQL Server Optimization? Thank you. P.S. I suppose, this is not the right place to ask server related questions. Should I delete it or maybe it can be migrated to serverfault?

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• WebLogic JDBC Use of Oracle Wallet for SSL

  - by Steve Felts

  Introduction Secure Sockets Layer (SSL) can be used to secure the connection between the middle tier “client”, WebLogic Server (WLS) in this case, and the Oracle database server.  Data between WLS and database can be encrypted.  The server can be authenticated so you have proof that the database can be trusted by validating a certificate from the server.  The client can be authenticated so that the database only accepts connections from clients that it trusts. Similar to the discussion in an earlier article about using the Oracle wallet for database credentials, the Oracle wallet can also be used with SSL to store the keys and certificates.  By using it correctly, clear text passwords can be eliminated from the JDBC configuration and client/server configuration can be simplified by sharing the wallet across multiple datasources. There is a very good Oracle Technical White Paper on using SSL with the Oracle thin driver at http://www.oracle.com/technetwork/database/enterprise-edition/wp-oracle-jdbc-thin-ssl-130128.pdf [LINK1].  The link http://www.oracle.com/technetwork/middleware/weblogic/index-087556.html [LINK2] describes how to use WebLogic Server with Oracle JDBC Driver SSL. The information in this article is a guide on what steps need to be taken in the variety of available options; use the links above for details. SSL from the driver to the database server is basically turned on by specifying a protocol of “tcps” in the URL.  However, there is a fair amount of setup needed.  Also remember that there is an overhead in performance. Creating the wallets The common use cases are 1. “data encryption and server-only authentication”, requiring just a trust store, or 2. “data encryption and authentication of both tiers” (client and server), requiring a trust store and a key store. It is recommended to use the auto-login wallet type so that clear text passwords are not needed in the datasource configuration to open the wallet.  The store type for an auto-login wallet is “SSO” (Single Sign On), not “JKS” or “PKCS12” as in [LINK2].  The file name is “cwallet.sso”. Wallets are created using the orapki tool.  They need to be created based on the usage (encryption and/or authentication).  This is discussed in detail in [LINK1] in Appendix B or in the Advanced Security Administrator’s Guide of the Database documentation. Database Server Configuration It is necessary to update the sqlnet.ora and listener.ora files with the directory location of the wallet using WALLET_LOCATION.  These files also indicate whether or not SSL_CLIENT_AUTHENTICATION is being used (true or false). The Oracle Listener must also be configured to use the TCPS protocol.  The recommended port is 2484. LISTENER = (ADDRESS_LIST= (ADDRESS=(PROTOCOL=tcps)(HOST=servername)(PORT=2484))) WebLogic Server Classpath The WebLogic Server CLASSPATH must have three additional security files. The files that need to be added to the WLS CLASSPATH are $MW_HOME/modules/com.oracle.osdt_cert_1.0.0.0.jar $MW_HOME/modules/com.oracle.osdt_core_1.0.0.0.jar $MW_HOME/modules/com.oracle.oraclepki_1.0.0.0.jar One way to do this is to add them to PRE_CLASSPATH environment variable for use with the standard WebLogic scripts. Setting the Oracle Security Provider It’s necessary to enable the Oracle PKI provider on the client side.  This can either be done statically by updating the java.security file under the JRE or dynamically by setting it in a WLS startup class using java.security.Security.insertProviderAt(new oracle.security.pki.OraclePKIProvider (), 3); See the full example of the startup class in [LINK2]. Datasource Configuration When creating a WLS datasource, set the PROTOCOL in the URL to tcps as in the following. jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS=(PROTOCOL=tcps)(HOST=host)(PORT=port))(CONNECT_DATA=(SERVICE_NAME=myservice))) For encryption and server authentication, use the datasource connection properties: - javax.net.ssl.trustStore=location of wallet file on the client - javax.net.ssl.trustStoreType=”SSO” For client authentication, use the datasource connection properties: - javax.net.ssl.keyStore=location of wallet file on the client - javax.net.ssl.keyStoreType=”SSO” Note that the driver connection properties for the wallet require a file name, not a directory name. Active GridLink ONS over SSL For completeness, there is another SSL usage for WLS datasources.  The communication with the Oracle Notification Service (ONS) for load balancing information and node up/down events can use SSL also. Create an auto-login wallet and use the wallet on the client and server.  The following is a sample sequence to create a test wallet for use with ONS. orapki wallet create -wallet ons -auto_login -pwd ONS_Wallet orapki wallet add -wallet ons -dn "CN=ons_test,C=US" -keysize 1024 -self_signed -validity 9999 -pwd ONS_Wallet orapki wallet export -wallet ons -dn "CN=ons_test,C=US" -cert ons/cert.txt -pwd ONS_Wallet On the database server side, it’s necessary to define the walletfile directory in the file $CRS_HOME/opmn/conf/ons.config and run onsctl stop/start. When configuring an Active GridLink datasource, the connection to the ONS must be defined.  In addition to the host and port, the wallet file directory must be specified.  By not giving a password, a SSO wallet is assumed. Summary To use SSL with the Oracle thin driver without any clear text passwords, use an SSO Oracle Wallet.  SSL support in the Oracle thin driver is available starting in 10g Release 2.

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• Checking who is connected to your server, with PowerShell.

  - by Fatherjack

  There are many occasions when, as a DBA, you want to see who is connected to your SQL Server, along with how they are connecting and what sort of activities they are carrying out. I’m going to look at a couple of ways of getting this information and compare the effort required and the results achieved of each. SQL Server comes with a couple of stored procedures to help with this sort of task – sp_who and its undocumented counterpart sp_who2. There is also the pumped up version of these called sp_whoisactive, written by Adam Machanic which does way more than these procedures. I wholly recommend you try it out if you don’t already know how it works. When it comes to serious interrogation of your SQL Server activity then it is absolutely indispensable. Anyway, back to the point of this blog, we are going to look at getting the information from sp_who2 for a remote server. I wrote this Powershell script a week or so ago and was quietly happy with it for a while. I’m relatively new to Powershell so forgive both my rather low threshold for entertainment and the fact that something so simple is a moderate achievement for me. $Server = 'SERVERNAME' $SMOServer = New-Object Microsoft.SQLServer.Management.SMO.Server $Server # connection and query stuff         $ConnectionStr = "Server=$Server;Database=Master;Integrated Security=True" $Query = "EXEC sp_who2" $Connection = new-object system.Data.SQLClient.SQLConnection $Table = new-object "System.Data.DataTable" $Connection.connectionstring = $ConnectionStr try{ $Connection.open() $Command = $Connection.CreateCommand() $Command.commandtext = $Query $result = $Command.ExecuteReader() $Table.Load($result) } catch{ # Show error $error[0] | format-list -Force } $Title = "Data access processes (" + $Table.Rows.Count + ")" $Table | Out-GridView -Title $Title $Connection.close() So this is pretty straightforward, create an SMO object that represents our chosen server, define a connection to the database and a table object for the results when we get them, execute our query over the connection, load the results into our table object and then, if everything is error free display these results to the PowerShell grid viewer. The query simply gets the results of ‘EXEC sp_who2′ for us. Depending on how many connections there are will influence how long the query runs. The grid viewer lets me sort and search the results so it can be a pretty handy way to locate troublesome connections. Like I say, I was quite pleased with this, it seems a pretty simple script and was working well for me, I have added a few parameters to control the output and give me more specific details but then I see a script that uses the $SMOServer object itself to provide the process information and saves having to define the connection object and query specifications. $Server = 'SERVERNAME' $SMOServer = New-Object Microsoft.SQLServer.Management.SMO.Server $Server $Processes = $SMOServer.EnumProcesses() $Title = "SMO processes (" + $Processes.Rows.Count + ")" $Processes | Out-GridView -Title $Title Create the SMO object of our server and then call the EnumProcesses method to get all the process information from the server. Staggeringly simple! The results are a little different though. Some columns are the same and we can see the same basic information so my first thought was to which runs faster – so that I can get my results more quickly and also so that I place less stress on my server(s). PowerShell comes with a great way of testing this – the Measure-Command function. All you have to do is wrap your piece of code in Measure-Command {[your code here]} and it will spit out the time taken to execute the code. So, I placed both of the above methods of getting SQL Server process connections in two Measure-Command wrappers and pressed F5! The Powershell console goes blank for a while as the code is executed internally when Measure-Command is used but the grid viewer windows appear and the console shows this. You can take the output from Measure-Command and format it for easier reading but in a simple comparison like this we can simply cross refer the TotalMilliseconds values from the two result sets to see how the two methods performed. The query execution method (running EXEC sp_who2 ) is the first set of timings and the SMO EnumProcesses is the second. I have run these on a variety of servers and while the results vary from execution to execution I have never seen the SMO version slower than the other. The difference has varied and the time for both has ranged from sub-second as we see above to almost 5 seconds on other systems. This difference, I would suggest is partly due to the cost overhead of having to construct the data connection and so on where as the SMO EnumProcesses method has the connection to the server already in place and just needs to call back the process information. There is also the difference in the data sets to consider. Let’s take a look at what we get and where the two methods differ Query execution method (sp_who2) SMO EnumProcesses Description - Urn What looks like an XML or JSON representation of the server name and the process ID SPID Spid The process ID Status Status The status of the process Login Login The login name of the user executing the command HostName Host The name of the computer where the  process originated BlkBy BlockingSpid The SPID of a process that is blocking this one DBName Database The database that this process is connected to Command Command The type of command that is executing CPUTime Cpu The CPU activity related to this process DiskIO - The Disk IO activity related to this process LastBatch - The time the last batch was executed from this process. ProgramName Program The application that is facilitating the process connection to the SQL Server. SPID1 - In my experience this is always the same value as SPID. REQUESTID - In my experience this is always 0 - Name In my experience this is always the same value as SPID and so could be seen as analogous to SPID1 from sp_who2 - MemUsage An indication of the memory used by this process but I don’t know what it is measured in (bytes, Kb, Mb…) - IsSystem True or False depending on whether the process is internal to the SQL Server instance or has been created by an external connection requesting data. - ExecutionContextID In my experience this is always 0 so could be analogous to REQUESTID from sp_who2. Please note, these are my own very brief descriptions of these columns, detail can be found from MSDN for columns in the sp_who results here http://msdn.microsoft.com/en-GB/library/ms174313.aspx. Where the columns are common then I would use that description, in other cases then the information returned is purely for interpretation by the reader. Rather annoyingly both result sets have useful information that the other doesn’t. sp_who2 returns Disk IO and LastBatch information which is really useful but the SMO processes method give you IsSystem and MemUsage which have their place in fault diagnosis methods too. So which is better? On reflection I think I prefer to use the sp_who2 method primarily but knowing that the SMO Enumprocesses method is there when I need it is really useful and I’m sure I’ll use it regularly. I’m OK with the fact that it is the slower method because Measure-Command has shown me how close it is to the other option and that it really isn’t a large enough margin to matter.

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• How does a search functionality fit in DDD with CQRS?

  - by Songo

  In Vaughn Vernon's book Implementing domain driven design and the accompanying sample application I found that he implemented a CQRS approach to the iddd_collaboration bounded context. He presents the following classes in the application service layer: CalendarApplicationService.java CalendarEntryApplicationService.java CalendarEntryQueryService.java CalendarQueryService.java I'm interested to know if an application will have a search page that feature numerous drop downs and check boxes with a smart text box to match different search patterns; How will you structure all that search logic? In a command service or a query service? Taking a look at the CalendarQueryService.java I can see that it has 2 methods for a huge query, but no logic at all to mix and match any search filters for example. I've heard that the application layer shouldn't have any business logic, so where will I construct my dynamic query? or maybe just clutter everything in the Query service?

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• Újabb Oracle TPC-H rekord 3 TB-on, a nem klaszterezett kategóriában

  - by Fekete Zoltán

  A TPC-H a döntéstámogatási, adattárházas, üzleti intelligencia rendszerek teljesítményét méri, www.tpc.org. Most a 3 TB-os méretben született új rekord a TPC-H teszten a non-clustered kategóriában az Oracle Database 11gR2-vel, Sun M9000 hardveren. „A nagy méretu rendszerekben elért TPC-H benchmark-rekordokkal az Oracle Database 11g továbbra is orzi vezeto helyét az adattárház-rendszerek között" - nyilatkozta Juan Loaiza, az Oracle rendszertechnológiáért felelos elso alelnöke. „Ez az eredmény bizonyítja, hogy az Oracle Database 11g és az Oracle Sun SPARC Enterprise M9000 kiszolgálója együttesen nagyteljesítményu alapot biztosít az ügyfelek adattárház-alkalmazásai számára." Az Oracle sajtóhír magyar nyelven: Az Oracle® Database 11g új világrekordot állított fel a Sun SPARC Enterprise M9000 kiszolgálón végzett három terabájtos fürtözés nélküli TPC-H sebességpróbán Az Oracle sajtóhír angol nyelven: Oracle® Database 11g Sets New World Record TPC-H Three Terabyte Non-Clustered Benchmark Result on Sun SPARC Enterprise M9000 Server

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• Slow in the Application but Fast in SQL Server Management Studio - from Erland

  - by Greg Low

  Our MVP buddy Erland Sommarskog doesn't post articles that often but when he does, you should read them. His latest post is here: http://www.sommarskog.se/query-plan-mysteries.html It talks about why a query might be slow when sent from an application but fast when you execute it in SSMS. But it covers way more than that. There is a great deal of good info on how queries are executed and query plans generated. Highly recommended!...(read more)

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• Alternative of SortedDictionary in Silverlight

  - by Rajneesh Verma

  Hi, As we know SortedDictionary is not not present in Silverlightso to find alternative of this i am using Dictionary as System.Collections.Generic . Dictionary (Of TKey, TValue ) . KeyCollection and for sorting i am using LINQ query. see the full code below. Dim sortedLists As New Dictionary(Of String, Object) Dim query = From sortedList In sortedLists Order By sortedList.Key Ascending Select sortedList.Key, sortedList.Value For Each que In query 'get the key value using que.Key 'get the value using...(read more)

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• I'm blogging again, and about time too

  - by fatherjack

  No, seriously, this one is about time. I recently had an issue in a work database where a query was giving random results, sometimes the query would return a row and other times it wouldn't. There was quite a bit of work distilling the query down to find the reason for this and I'll try to explain by demonstrating what was happening by using some sample data in a table with rather a contrived use case. Let's assume we have a table that is designed to have a start and end date for something, maybe...(read more)

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• Showplan Operator of the week - Assert

  As part of his mission to explain the Query Optimiser in practical terms, Fabiano attempts the feat of describing, one week at a time, all the major Showplan Operators used by SQL Server's Query Optimiser to build the Query Plan. He starts with Assert

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• Habanero

  - by csharp-source.net

  An Enterprise Application Framework for .Net that is ideally suited for developing applications in an agile manner. The framework is used for producing an application from the data layer through to the front-end. Free open source under the LGPL license, it includes ORM, code generation and runtime UI generation to create one application for the desktop & web. Features: * ORM: Map database tables to objects in code * Persist property values to and from the database * Define all mapping in a single XML file * Switch between database vendors with one setting * Support for MySQL, MS Sql Server, MS Access, Oracle, PostgreSQL, SQLite, Firebird * FireStarter GUI class definitions xml manager * Generate user interfaces and map properties to controls * Develop for both desktop (with Windows Forms) and web (with Gizmox' Visual WebGUI) * Generate new projects and code files * Generate UI forms from templates * Reverse engineer class definitions from existing databases * Support variable data sources, including an in-memory database. Ships with Firestarter a free database reverse engineering, Domain Modelling and Code Generator.

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• Architecture for subscription based application

  - by John

  This is about the architecture of my application I think. I have a Rails application where companies can administrate all things related to clients. Companies can buy a subscription and their users can access the application online. Hopefully I will get multiple companies subscribing to my appplication/service. Thing is, what should I do with my code and database? Seperate app code base and database per company One app code base but seperate database per company One app code base and one database The decision I am to make involves security (e.g. user from company X should not see any data from company Y) performance (let's suppose it becomes successful, it should have a good performance) and scalability (again, if successful, it should have a good performance but also easy for me to handle all the companies, code changes, etc) For sake of maintainability, I tend to opt for the one code base. For the database I really don't know at this moment. So what do you think is the best option?

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• REST and PayPal

  - by Nikolay Fominyh

  Is it ok to query REST API and get redirect to third party from it, or it is only about resources? Let's look at following scenario: User gets to payment page User clicks on "Pay using paypal button" API query PayPal for redirect url API returns redirect url in response. Client side redirect goes here. User does PayPal routine and returns with token User query API with token API do token check and adds money Is this scenario complex for REST architecture?

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• AdSense Custom Search Ads - custom quesry

  - by Alex

  i'm trying to set up a custom search ad, but I am nost sure about the query. On the site it says (https://developers.google.com/custom-search-ads/docs/implementation-guide) 'query' should be dynamic based on your page. This variable targets the ads and therefore should always match what the user on your site has just performed a search for. Now, what I understand is: I have to program my page so that the query variable contains some custom words. Am I right? If a user gets to my site through clicking on an adsense, there is no way to "know" what the user looked for and display my query accordingly, right? Thanks for any help!

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• lots of dns requests from China, should I worry?

  - by nn4l

  I have turned on dns query logs, and when running "tail -f /var/log/syslog" I see that I get hundreds of identical requests from a single ip address: Apr 7 12:36:13 server17 named[26294]: client 121.12.173.191#10856: query: mydomain.de IN ANY + Apr 7 12:36:13 server17 named[26294]: client 121.12.173.191#44334: query: mydomain.de IN ANY + Apr 7 12:36:13 server17 named[26294]: client 121.12.173.191#15268: query: mydomain.de IN ANY + Apr 7 12:36:13 server17 named[26294]: client 121.12.173.191#59597: query: mydomain.de IN ANY + The frequency is about 5 - 10 requests per second, going on for about a minute. After that the same effect repeats from a different IP address. I have now logged about 10000 requests from about 25 ip addresses within just a couple of hours, all of them come from China according to "whois [ipaddr]". What is going on here? Is my name server under attack? Can I do something about this?

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• Oracle????????????????~BI/DWH????????(1)

  - by Yusuke.Yamamoto

  Oracle Database ???BI???????????????????????????????????????????????????????????????????????????????????? Oracle Database 11gR2 ??????????????????? ??????????(03:54)????????????? BI????????????(Oracle Database ??????????) Enterprise Manager ??SQL??????????????????????? ?????????????????????????????? BI????????????(Oracle Database ???????????/In-Memory Parallel Execution ???) Enterprise Manager ??SQL???????????????????????? ??????????????Oracle GRID Center ??????????????? ????????????????????????? ????????DWH????????????????·???????? ???? ???????????????!! Oracle Database??????? ??????|??????????? Oracle Enterprise Manager|??????????? DWH(?????????)??·??

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• Null Values And The T-SQL IN Operator

  - by Jesse

  I came across some unexpected behavior while troubleshooting a failing test the other day that took me long enough to figure out that I thought it was worth sharing here. I finally traced the failing test back to a SELECT statement in a stored procedure that was using the IN t-sql operator to exclude a certain set of values. Here’s a very simple example table to illustrate the issue: Customers CustomerId INT, NOT NULL, Primary Key CustomerName nvarchar(100) NOT NULL SalesRegionId INT NULL   The ‘SalesRegionId’ column contains a number representing the sales region that the customer belongs to. This column is nullable because new customers get created all the time but assigning them to sales regions is a process that is handled by a regional manager on a periodic basis. For the purposes of this example, the Customers table currently has the following rows: CustomerId CustomerName SalesRegionId 1 Customer A 1 2 Customer B NULL 3 Customer C 4 4 Customer D 2 5 Customer E 3   How could we write a query against this table for all customers that are NOT in sales regions 2 or 4? You might try something like this: 1: SELECT 2: CustomerId, 3: CustomerName, 4: SalesRegionId 5: FROM Customers 6: WHERE SalesRegionId NOT IN (2,4)   Will this work? In short, no; at least not in the way that you might expect. Here’s what this query will return given the example data we’re working with: CustomerId CustomerName SalesRegionId 1 Customer A 1 5 Customer E 5   I was expecting that this query would also return ‘Customer B’, since that customer has a NULL SalesRegionId. In my mind, having a customer with no sales region should be included in a set of customers that are not in sales regions 2 or 4.When I first started troubleshooting my issue I made note of the fact that this query should probably be re-written without the NOT IN clause, but I didn’t suspect that the NOT IN clause was actually the source of the issue. This particular query was only one minor piece in a much larger process that was being exercised via an automated integration test and I simply made a poor assumption that the NOT IN would work the way that I thought it should. So why doesn’t this work the way that I thought it should? From the MSDN documentation on the t-sql IN operator: If the value of test_expression is equal to any value returned by subquery or is equal to any expression from the comma-separated list, the result value is TRUE; otherwise, the result value is FALSE. Using NOT IN negates the subquery value or expression. The key phrase out of that quote is, “… is equal to any expression from the comma-separated list…”. The NULL SalesRegionId isn’t included in the NOT IN because of how NULL values are handled in equality comparisons. From the MSDN documentation on ANSI_NULLS: The SQL-92 standard requires that an equals (=) or not equal to (<>) comparison against a null value evaluates to FALSE. When SET ANSI_NULLS is ON, a SELECT statement using WHERE column_name = NULL returns zero rows even if there are null values in column_name. A SELECT statement using WHERE column_name <> NULL returns zero rows even if there are nonnull values in column_name. In fact, the MSDN documentation on the IN operator includes the following blurb about using NULL values in IN sub-queries or expressions that are used with the IN operator: Any null values returned by subquery or expression that are compared to test_expression using IN or NOT IN return UNKNOWN. Using null values in together with IN or NOT IN can produce unexpected results. If I were to include a ‘SET ANSI_NULLS OFF’ command right above my SELECT statement I would get ‘Customer B’ returned in the results, but that’s definitely not the right way to deal with this. We could re-write the query to explicitly include the NULL value in the WHERE clause: 1: SELECT 2: CustomerId, 3: CustomerName, 4: SalesRegionId 5: FROM Customers 6: WHERE (SalesRegionId NOT IN (2,4) OR SalesRegionId IS NULL)   This query works and properly includes ‘Customer B’ in the results, but I ultimately opted to re-write the query using a LEFT OUTER JOIN against a table variable containing all of the values that I wanted to exclude because, in my case, there could potentially be several hundred values to be excluded. If we were to apply the same refactoring to our simple sales region example we’d end up with: 1: DECLARE @regionsToIgnore TABLE (IgnoredRegionId INT) 2: INSERT @regionsToIgnore values (2),(4) 3:  4: SELECT 5: c.CustomerId, 6: c.CustomerName, 7: c.SalesRegionId 8: FROM Customers c 9: LEFT OUTER JOIN @regionsToIgnore r ON r.IgnoredRegionId = c.SalesRegionId 10: WHERE r.IgnoredRegionId IS NULL By performing a LEFT OUTER JOIN from Customers to the @regionsToIgnore table variable we can simply exclude any rows where the IgnoredRegionId is null, as those represent customers that DO NOT appear in the ignored regions list. This approach will likely perform better if the number of sales regions to ignore gets very large and it also will correctly include any customers that do not yet have a sales region.

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• Enzo Backup for SQL Azure Beta Released!

  - by ScottKlein

  Blue Syntax is happy to announce the release of their SQL Azure database backup product! Enzo Backup for SQL Azure offers unparalleled backup and restored functionlity and flexibility of a SQL Azure database. You can download the beta release here: http://www.bluesyntax.net/backup.aspx With Enzo Backup for SQL Azure, you can: Create a backup blob, or a backup file from a SQL Azure database Restore a SQL Azure database from a backup blob, or a backup file Perform limited backup and restore of SQL Server databases (see details) Run backups entirely in the cloud using a remote agent Backup a single schema of a database Restore specific tables only Copy backup devices from on-premise to the cloud Use a command-line utility to perform backup operations Perform transactionally consistent backups for SQL Azure Please download it and provide us your feed back!

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• Using EUSM to manage EUS mappings in OUD

  - by Sylvain Duloutre

  EUSM is a command line tool that can be used to manage the EUS settings starting with the 11.1 release of Oracle. In the 11.1 release the tool is not yet documented in the Oracle EUS documentation, but this is planned for a coming release. The same commands used by EUSM can be performed from the Database Console GUI or from Grid Control*. For more details, search for the document ID 1085065.1 on OTN. The examples below don't include all the EUSM options, only the options that are used by EUS. EUSM is user friendly and intuitive. Typing eusm help <option> lists the parameters to be used for any of the available options. Here are the options related to connectivity with OUD : ldap_host="gnb.fr.oracle.com" - name of the OUD server. ldap_port=1389 - nonSSL (SASL) port used for OUD connections.  ldap_user_dn="cn=directory manager" - OUD administrator nameldap_user_password="welcome1" - OUD administrator password Find below common commands: To List Enterprise roles in OUD eusm listEnterpriseRoles domain_name=<Domain> realm_dn=<realm> ldap_host=<hostname> ldap_port=<port> ldap_user_dn=<oud administrator> ldap_user_password=<oud admin password> To List Mappings eusm listMappings domain_name=<Domain> realm_dn=<realm> ldap_host=<hostname> ldap_port=<port> ldap_user_dn=<oud admin> ldap_user_password=<oud admin password> To List Enterprise Role Info eusm listEnterpriseRoleInfo enterprise_role=<rdn of enterprise role> domain_name=<Domain> realm_dn=<realm> ldap_host=<hostname> ldap_port=<port> ldap_user_dn="<oud admin>" ldap_user_password=<oud admin password> To Create Enterprise Role eusm createRole enterprise_role=<rdn of the enterprise role> domain_name=<Domain> realm_dn=<realm> ldap_host=<hostname> ldap_port=<port> ldap_user_dn="<oud admin>" ldap_user_password=<oud admin password> To Create User-Schema Mapping eusm createMapping database_name=<SID of target database> realm_dn="<realm>" map_type=<ENTRY/SUBTREE> map_dn="<dn of enterprise user>" schema="<name of the shared schema>" ldap_host=<oud hostname> ldap_port=<port> ldap_user_dn="<oud admin>" ldap_user_password="<oud admin password>" To Create Proxy Permission eusm createProxyPerm proxy_permission=<Name of the proxypermission> domain_name=<Domain> realm_dn="<realm>" ldap_host=<hostname> ldap_port=<port> ldap_user_dn="<oud admin>" ldap_user_password=<oud admin password> To Grant Proxy permission to Proxy group eusm grantProxyPerm proxy_permission=<Name of the proxy permission> domain_name=<Domain> realm_dn="<realm>" ldap_host=<hostname> ldap_port=<port> ldap_user_dn="<oud admin>" ldap_user_password=<password> group_dn="<dn of the enterprise group>" To Map proxy permission to proxy user in DB eusm addTargetUser proxy_permission=<Name of the proxy permission> domain_name=<Domain> realm_dn="<realm>" ldap_host=<hostname> ldap_port=<port> ldap_user_dn="<oud admin>" ldap_user_password=<oud admin password> database_name=<SID of the target database> target_user=<target database user> dbuser=<Database user with DBA privileges> dbuser_password=<database user password> dbconnect_string=<database_host>:<port>:<DBSID> Enterprise role to Global role mapping eusm addGlobalRole enterprise_role=<rdn of the enterprise role> domain_name=<Domain> realm_dn="<realm>" database_name=<SID of the target database> global_role=<name of the global role defined in the target database> dbuser=<database user> dbuser_password=<database user password> dbconnect_string=<database_host>:<port>:<DBSID> ldap_host=<oid_hostname> ldap_port=<port> ldap_user_dn="<oud admin>" ldap_user_password=<oud admin password>

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• Troubleshooting Blocked Transaction in SQL Server

  - by ChrisD

  While troubleshooting a blocked transaction issue recently, I found this code online.  My apologies in not citing its source, but its lost in my browse history some where.   While the transaction is executing and blocked, open a connection to the database containing the transaction and run the following to return both the SQL statement blocked (the Victim), as well as the statement that’s causing the block (the Culprit)   -- prepare a table so that we can filter out sp_who2 results DECLARE @who TABLE(BlockedId INT, Status VARCHAR(MAX), LOGIN VARCHAR(MAX), HostName VARCHAR(MAX), BlockedById VARCHAR(MAX), DBName VARCHAR(MAX), Command VARCHAR(MAX), CPUTime INT, DiskIO INT, LastBatch VARCHAR(MAX), ProgramName VARCHAR(MAX), SPID_1 INT, REQUESTID INT) INSERT INTO @who EXEC sp_who2 --select the blocked and blocking queries (if any) as SQL text SELECT ( SELECT TEXT FROM sys.dm_exec_sql_text( (SELECT handle FROM ( SELECT CAST(sql_handle AS VARBINARY(128)) AS handle FROM sys.sysprocesses WHERE spid = BlockedId ) query) ) ) AS 'Blocked Query (Victim)', ( SELECT TEXT FROM sys.dm_exec_sql_text( (SELECT handle FROM ( SELECT CAST(sql_handle AS VARBINARY(128)) AS handle FROM sys.sysprocesses WHERE spid = BlockedById ) query) ) ) AS 'Blocking Query (Culprit)' FROM @who WHERE BlockedById != ' .'

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• OOW 2012: Slides Download

  - by Mike Dietrich

  Hm ... you might ask yourself why there are no Oracle Database 12c slides available for download, neither in the OOW 2012 content system nor on our blog (and I believe nowhere else). Simple reason: As long as Oracle Database 12c is not released and available we are not allowed to offer slides for download. Therefore people were simply taking pictures during the 12c sessions with their phones, iPods and cameras. Roy took a nice shot: Sorry for that - we'll make the content available as soon as Oracle Database 12c gets released. In between you can download our OOW 2012 talk Database Upgrades on Steroids: Real Speed, Real Customers, Real Secrets as PDF (3.4MB) - but the 12c content is currently not in that PDF. But a lot of information applies to your source database and/or to any upgrade - so it still might be helpful. And unfortunately the same 12c rule applies to the slides guiding you through our Hands-On-Lab on Tuesday. Thanks

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• Easy QueryBuilder - A User-Friendly Ad-Hoc Advanced Search Solution

  Constructing an easy and powerful QueryBuilder interface becomes more important for complex data grid filtering and accurate reporting services. In this article, I'll discuss how to build a query search engine using ASP.NET AJAX and dynamic SQL. The main goal is to provide an interactive interface to allow users select query attributes, operators, attribute values, and T-SQL operators so that the data context query list can be easily composed and a search engine is invoked.

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