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• SQL SERVER – Asynchronous Update and Timestamp – Check if Row Values are Changed Since Last Retrieve

  - by pinaldave

  Here is the question received just this morning. “Pinal, Our application is much different than other application you might have come across. In simple words, I would like to call it Asynchronous Updated Application. We need your quick opinion about one of the situation which we are facing. From business side: We have bidding system (similar to eBay but not exactly) and where multiple parties bid on one item, during the last few minutes of bidding many parties try to bid at the same time with the same price. When they hit submit, we would like to check if the original data which they retrieved is changed or not. If the original data which they have retrieved is the same, we will accept their new proposed price. If original data are changed, they will have to resubmit the data with new price. From technical side: We have a row which we retrieve in our application. Multiple users are retrieving the same row. Some of the users will update the value of the row and submit. However, only the very first user should be allowed to update the row and remaining all the users will have to re-fetch the row and updated it once again. We do not want to lock any record as that will create other problems. Do you have any solution for this kind of situation?” Fantastic Question. I believe there is good chance that we can use timestamp datatype in this kind of application. Before we continue let us see following simple example. USE tempdb GO CREATE TABLE SampleTable (ID INT, Col1 VARCHAR(100), TimeStampCol TIMESTAMP) GO INSERT INTO SampleTable (ID, Col1) VALUES (1, 'FirstVal') GO SELECT ID, Col1, TimeStampCol FROM SampleTable st GO UPDATE SampleTable SET Col1 = 'NextValue' GO SELECT ID, Col1, TimeStampCol FROM SampleTable st GO DROP TABLE SampleTable GO Now let us see the resultset. Here is the simple explanation of the scenario. We created a table with simple column with TIMESTAMP datatype. When we inserted a very first value the timestamp was generated. When we updated any value in that row, the timestamp was updated with the new value. Every single time when we update any value in the row, it will generate new timestamp value. Now let us apply this in an original question’s scenario. In that case multiple users are retrieving the same row. Everybody will have the same now same TimeStamp with them. Before any user update any value they should once again retrieve the timestamp from the table and compare with the timestamp they have with them. If both of the timestamp have the same value – the original row has not been updated and we can safely update the row with the new value. After initial update, now the row will contain a new timestamp. Any subsequent update to the same row should also go to the same process of checking the value of the timestamp they have in their memory. In this case, the timestamp from memory will be different from the timestamp in the row. This indicates that row in the table has changed and new updates should not be allowed. I believe timestamp can be very very useful in this kind of scenario. Is there any better alternative? Please leave a comment with the suggestion and I will post on the blog with due credit. 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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• Windows Azure SDK 1.3 addresses early adopter feedback

  - by Eric Nelson

  At the end of November 2010 we released a new version of the Windows Azure SDK which contains many new features driven by the great feedback of early adopters plus a shiny new portal. New Portal implemented in Silverlight: The new portal is implemented using Silverlight and replaces the (IMHO rather clunky) original HTML + JavaScript portal. It is 100% better although does still have a few bugs. Enjoy! P.S. You can if you wish still use the old portal:   New runtime functionality: The following functionality is now generally available through the Windows Azure SDK and Windows Azure Tools for Visual Studio and the new Windows Azure Management Portal: Elevated Privileges and Full IIS. You can now run a portion or all of your code in Web and Worker roles with elevated administrator privileges. The Web role now provides Full IIS functionality, which enables multiple IIS sites per Web role and the ability to install IIS modules. Remote Desktop functionality enables you to connect to a running instance of your application or service in order to monitor activity and troubleshoot common problems. Windows Server 2008 R2 Roles: Windows Azure now supports Windows Server 2008 R2 in its Web, worker and VM roles. This new support enables you to take advantage of the full range of Windows Server 2008 R2 features such as IIS 7.5, AppLocker, and enhanced command-line and automated management using PowerShell Version 2.0. New runtime functionality – in beta: Windows Azure Virtual Machine Role: Support for more types of new and existing Windows applications will soon be available with the introduction of the Virtual Machine (VM) role. You can move more existing applications to Windows Azure, reducing the need to make costly code or deployment changes. Extra Small Windows Azure Instance, which is priced at $0.05 per compute hour, provides developers with a cost-effective training and development environment. Developers can also use the Extra Small instance to prototype cloud solutions at a lower cost. Windows Azure Connect: (formerly Project Sydney), which enables a simple and easy-to-manage mechanism to set up IP-based network connectivity between on-premises and Windows Azure resources, is the first Windows Azure Virtual Network feature that we’re making available as a CTP. You can sign up for any of the betas via the Windows Azure Management Portal. Improved processes and simplified operations New portal! (see above) Access to new diagnostic information including the ability to click on a role to see role type, deployment time and last reboot time A new sign-up process that dramatically reduces the number of steps needed to sign up for Windows Azure. New scenario based Windows Azure Platform forums to help answer questions and share knowledge more efficiently. Multiple Service Administrators: Windows Azure now supports multiple Windows Live IDs to have administrator privileges on the same Windows Azure account. The objective is to make it easy for a team to work on the same Windows Azure account while using their individual Windows Live IDs.   Related Links Please also let us know through Microsoft Platform Ready if and when you intend to build an application using the Windows Azure Platform. Or indeed if you already have (Well done). You will get access to some great benefits if you do (more on that in a future post). It also really helps us better understand the demand out there which directly impacts how we will plan the next six months of activities around the Windows Azure Platform. Visit Microsoft Platform Ready to tell us about your plans for your applications UK based? Interested in the Windows Azure Platform? Join http://ukazure.ning.com Get started with the Windows Azure Platform http://bit.ly/startazure

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• Need WIF Training?

  - by Your DisplayName here!

  I spend numerous hours every month answering questions about WIF and identity in general. This made me realize that this is still quite a complicated topic once you go beyond the standard fedutil stuff. My good friend Brock and I put together a two day training course about WIF that covers everything we think is important. The course includes extensive lab material where you take standard application and apply all kinds of claims and federation techniques and technologies like WS-Federation, WS-Trust, session management, delegation, home realm discovery, multiple identity providers, Access Control Service, REST, SWT and OAuth. The lab also includes the latest version of the thinktecture identityserver and you will learn how to use and customize it. If you are looking for an open enrollment style of training, have a look here. Or contact me directly! The course outline looks as follows: Day 1 Intro to Claims-based Identity & the Windows Identity Foundation WIF introduces important concepts like conversion of security tokens and credentials to claims, claims transformation and claims-based authorization. In this module you will learn the basics of the WIF programming model and how WIF integrates into existing .NET code. Externalizing Authentication for Web Applications WIF includes support for the WS-Federation protocol. This protocol allows separating business and authentication logic into separate (distributed) applications. The authentication part is called identity provider or in more general terms - a security token service. This module looks at this scenario both from an application and identity provider point of view and walks you through the necessary concepts to centralize application login logic both using a standard product like Active Directory Federation Services as well as a custom token service using WIF’s API support. Externalizing Authentication for SOAP Services One big benefit of WIF is that it unifies the security programming model for ASP.NET and WCF. In the spirit of the preceding modules, we will have a look at how WIF integrates into the (SOAP) web service world. You will learn how to separate authentication into a separate service using the WS-Trust protocol and how WIF can simplify the WCF security model and extensibility API. Day 2 Advanced Topics:  Security Token Service Architecture, Delegation and Federation The preceding modules covered the 80/20 cases of WIF in combination with ASP.NET and WCF. In many scenarios this is just the tip of the iceberg. Especially when two business partners decide to federate, you usually have to deal with multiple token services and their implications in application design. Identity delegation is a feature that allows transporting the client identity over a chain of service invocations to make authorization decisions over multiple hops. In addition you will learn about the principal architecture of a STS, how to customize the one that comes with this training course, as well as how to build your own. Outsourcing Authentication:  Windows Azure & the Azure AppFabric Access Control Service Microsoft provides a multi-tenant security token service as part of the Azure platform cloud offering. This is an interesting product because it allows to outsource vital infrastructure services to a managed environment that guarantees uptime and scalability. Another advantage of the Access Control Service is, that it allows easy integration of both the “enterprise” protocols like WS-* as well as “web identities” like LiveID, Google or Facebook into your applications. ACS acts as a protocol bridge in this case where the application developer doesn’t need to implement all these protocols, but simply uses a service to make it happen. Claims & Federation for the Web and Mobile World Also the web & mobile world moves to a token and claims-based model. While the mechanics are almost identical, other protocols and token types are used to achieve better HTTP (REST) and JavaScript integration for in-browser applications and small footprint devices. Also patterns like how to allow third party applications to work with your data without having to disclose your credentials are important concepts in these application types. The nice thing about WIF and its powerful base APIs and abstractions is that it can shield application logic from these details while you can focus on implementing the actual application. HTH

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• Creating a Corporate Data Hub

  - by BuckWoody

  The Windows Azure Marketplace has a rich assortment of data and software offerings for you to use – a type of Software as a Service (SaaS) for IT workers, not necessarily for end-users. Among those offerings is the “Data Hub” – a  codename for a project that ironically actually does what the codename says. In many of our organizations, we have multiple data quality issues. Finding data is one problem, but finding it just once is often a bigger problem. Lots of departments and even individuals have stored the same data more than once, and in some cases, made changes to one of the copies. It’s difficult to know which location or version of the data is authoritative. Then there’s the problem of accessing the data. It’s fairly straightforward to publish a database, share or other location internally to store the data. But then you have to figure out who owns it, how it is controlled, and pass out the various connection strings to those who want to use it. And then you need to figure out how to let folks access the internal data externally – bringing up all kinds of security issues. Finally, in many cases our user community wants us to combine data from the internally sources with external data, bringing up the security, strings, and exploration features up all over again. Enter the Data Hub. This is an online offering, where you assign an administrator and data stewards. You import the data into the service, and it’s available to you - and only you and your organization if you wish. The basic steps for this service are to set up the portal for your company, assign administrators and permissions, and then you assign data areas and import data into them. From there you make them discoverable, and then you have multiple options that you or your users can access that data. You’re then able, if you wish, to combine that data with other data in one location. So how does all that work? What about security? Is it really that easy? And can you really move the data definition off to the Subject Matter Experts (SME’s) that know the particular data stack better than the IT team does? Well, nothing good is easy – but using the Data Hub is actually pretty simple. I’ll give you a link in a moment where you can sign up and try this yourself. Once you sign up, you assign an administrator. From there you’ll create data areas, and then use a simple interface to bring the data in. All of this is done in a portal interface – nothing to install, configure, update or manage. After the data is entered in, and you’ve assigned meta-data to describe it, your users have multiple options to access it. They can simply use the portal – which actually has powerful visualizations you can use on any platform, even mobile phones or tablets.     Your users can also hit the data with Excel – which gives them ultimate flexibility for display, all while using an authoritative, single reference for the data. Since the service is online, they can do this wherever they are – given the proper authentication and permissions. You can also hit the service with simple API calls, like this one from C#: http://msdn.microsoft.com/en-us/library/hh921924  You can make HTTP calls instead of code, and the data can even be exposed as an OData Feed. As you can see, there are a lot of options. You can check out the offering here: http://www.microsoft.com/en-us/sqlazurelabs/labs/data-hub.aspx and you can read the documentation here: http://msdn.microsoft.com/en-us/library/hh921938

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• How to Load Oracle Tables From Hadoop Tutorial (Part 5 - Leveraging Parallelism in OSCH)

  - by Bob Hanckel

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Using OSCH: Beyond Hello World In the previous post we discussed a “Hello World” example for OSCH focusing on the mechanics of getting a toy end-to-end example working. In this post we are going to talk about how to make it work for big data loads. We will explain how to optimize an OSCH external table for load, paying particular attention to Oracle’s DOP (degree of parallelism), the number of external table location files we use, and the number of HDFS files that make up the payload. We will provide some rules that serve as best practices when using OSCH. The assumption is that you have read the previous post and have some end to end OSCH external tables working and now you want to ramp up the size of the loads. Using OSCH External Tables for Access and Loading OSCH external tables are no different from any other Oracle external tables.  They can be used to access HDFS content using Oracle SQL: SELECT * FROM my_hdfs_external_table; or use the same SQL access to load a table in Oracle. INSERT INTO my_oracle_table SELECT * FROM my_hdfs_external_table; To speed up the load time, you will want to control the degree of parallelism (i.e. DOP) and add two SQL hints. ALTER SESSION FORCE PARALLEL DML PARALLEL  8; ALTER SESSION FORCE PARALLEL QUERY PARALLEL 8; INSERT /*+ append pq_distribute(my_oracle_table, none) */ INTO my_oracle_table SELECT * FROM my_hdfs_external_table; There are various ways of either hinting at what level of DOP you want to use.  The ALTER SESSION statements above force the issue assuming you (the user of the session) are allowed to assert the DOP (more on that in the next section).  Alternatively you could embed additional parallel hints directly into the INSERT and SELECT clause respectively. /*+ parallel(my_oracle_table,8) *//*+ parallel(my_hdfs_external_table,8) */ Note that the "append" hint lets you load a target table by reserving space above a given "high watermark" in storage and uses Direct Path load.  In other doesn't try to fill blocks that are already allocated and partially filled. It uses unallocated blocks.  It is an optimized way of loading a table without incurring the typical resource overhead associated with run-of-the-mill inserts.  The "pq_distribute" hint in this context unifies the INSERT and SELECT operators to make data flow during a load more efficient. Finally your target Oracle table should be defined with "NOLOGGING" and "PARALLEL" attributes.   The combination of the "NOLOGGING" and use of the "append" hint disables REDO logging, and its overhead.  The "PARALLEL" clause tells Oracle to try to use parallel execution when operating on the target table. Determine Your DOP It might feel natural to build your datasets in Hadoop, then afterwards figure out how to tune the OSCH external table definition, but you should start backwards. You should focus on Oracle database, specifically the DOP you want to use when loading (or accessing) HDFS content using external tables. The DOP in Oracle controls how many PQ slaves are launched in parallel when executing an external table. Typically the DOP is something you want to Oracle to control transparently, but for loading content from Hadoop with OSCH, it's something that you will want to control. Oracle computes the maximum DOP that can be used by an Oracle user. The maximum value that can be assigned is an integer value typically equal to the number of CPUs on your Oracle instances, times the number of cores per CPU, times the number of Oracle instances. For example, suppose you have a RAC environment with 2 Oracle instances. And suppose that each system has 2 CPUs with 32 cores. The maximum DOP would be 128 (i.e. 2*2*32). In point of fact if you are running on a production system, the maximum DOP you are allowed to use will be restricted by the Oracle DBA. This is because using a system maximum DOP can subsume all system resources on Oracle and starve anything else that is executing. Obviously on a production system where resources need to be shared 24x7, this can’t be allowed to happen. The use cases for being able to run OSCH with a maximum DOP are when you have exclusive access to all the resources on an Oracle system. This can be in situations when your are first seeding tables in a new Oracle database, or there is a time where normal activity in the production database can be safely taken off-line for a few hours to free up resources for a big incremental load. Using OSCH on high end machines (specifically Oracle Exadata and Oracle BDA cabled with Infiniband), this mode of operation can load up to 15TB per hour. The bottom line is that you should first figure out what DOP you will be allowed to run with by talking to the DBAs who manage the production system. You then use that number to derive the number of location files, and (optionally) the number of HDFS data files that you want to generate, assuming that is flexible. Rule 1: Find out the maximum DOP you will be allowed to use with OSCH on the target Oracle system Determining the Number of Location Files Let’s assume that the DBA told you that your maximum DOP was 8. You want the number of location files in your external table to be big enough to utilize all 8 PQ slaves, and you want them to represent equally balanced workloads. Remember location files in OSCH are metadata lists of HDFS files and are created using OSCH’s External Table tool. They also represent the workload size given to an individual Oracle PQ slave (i.e. a PQ slave is given one location file to process at a time, and only it will process the contents of the location file.) Rule 2: The size of the workload of a single location file (and the PQ slave that processes it) is the sum of the content size of the HDFS files it lists For example, if a location file lists 5 HDFS files which are each 100GB in size, the workload size for that location file is 500GB. The number of location files that you generate is something you control by providing a number as input to OSCH’s External Table tool. Rule 3: The number of location files chosen should be a small multiple of the DOP Each location file represents one workload for one PQ slave. So the goal is to keep all slaves busy and try to give them equivalent workloads. Obviously if you run with a DOP of 8 but have 5 location files, only five PQ slaves will have something to do and the other three will have nothing to do and will quietly exit. If you run with 9 location files, then the PQ slaves will pick up the first 8 location files, and assuming they have equal work loads, will finish up about the same time. But the first PQ slave to finish its job will then be rescheduled to process the ninth location file, potentially doubling the end to end processing time. So for this DOP using 8, 16, or 32 location files would be a good idea. Determining the Number of HDFS Files Let’s start with the next rule and then explain it: Rule 4: The number of HDFS files should try to be a multiple of the number of location files and try to be relatively the same size In our running example, the DOP is 8. This means that the number of location files should be a small multiple of 8. Remember that each location file represents a list of unique HDFS files to load, and that the sum of the files listed in each location file is a workload for one Oracle PQ slave. The OSCH External Table tool will look in an HDFS directory for a set of HDFS files to load.  It will generate N number of location files (where N is the value you gave to the tool). It will then try to divvy up the HDFS files and do its best to make sure the workload across location files is as balanced as possible. (The tool uses a greedy algorithm that grabs the biggest HDFS file and delegates it to a particular location file. It then looks for the next biggest file and puts in some other location file, and so on). The tools ability to balance is reduced if HDFS file sizes are grossly out of balance or are too few. For example suppose my DOP is 8 and the number of location files is 8. Suppose I have only 8 HDFS files, where one file is 900GB and the others are 100GB. When the tool tries to balance the load it will be forced to put the singleton 900GB into one location file, and put each of the 100GB files in the 7 remaining location files. The load balance skew is 9 to 1. One PQ slave will be working overtime, while the slacker PQ slaves are off enjoying happy hour. If however the total payload (1600 GB) were broken up into smaller HDFS files, the OSCH External Table tool would have an easier time generating a list where each workload for each location file is relatively the same.  Applying Rule 4 above to our DOP of 8, we could divide the workload into160 files that were approximately 10 GB in size.  For this scenario the OSCH External Table tool would populate each location file with 20 HDFS file references, and all location files would have similar workloads (approximately 200GB per location file.) As a rule, when the OSCH External Table tool has to deal with more and smaller files it will be able to create more balanced loads. How small should HDFS files get? Not so small that the HDFS open and close file overhead starts having a substantial impact. For our performance test system (Exadata/BDA with Infiniband), I compared three OSCH loads of 1 TiB. One load had 128 HDFS files living in 64 location files where each HDFS file was about 8GB. I then did the same load with 12800 files where each HDFS file was about 80MB size. The end to end load time was virtually the same. However when I got ridiculously small (i.e. 128000 files at about 8MB per file), it started to make an impact and slow down the load time. What happens if you break rules 3 or 4 above? Nothing draconian, everything will still function. You just won’t be taking full advantage of the generous DOP that was allocated to you by your friendly DBA. The key point of the rules articulated above is this: if you know that HDFS content is ultimately going to be loaded into Oracle using OSCH, it makes sense to chop them up into the right number of files roughly the same size, derived from the DOP that you expect to use for loading. Next Steps So far we have talked about OLH and OSCH as alternative models for loading. That’s not quite the whole story. They can be used together in a way that provides for more efficient OSCH loads and allows one to be more flexible about scheduling on a Hadoop cluster and an Oracle Database to perform load operations. The next lesson will talk about Oracle Data Pump files generated by OLH, and loaded using OSCH. It will also outline the pros and cons of using various load methods.  This will be followed up with a final tutorial lesson focusing on how to optimize OLH and OSCH for use on Oracle's engineered systems: specifically Exadata and the BDA. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;}

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• Creating a voxel world with 3D arrays using threads

  - by Sean M.

  I am making a voxel game (a bit like Minecraft) in C++(11), and I've come across an issue with creating a world efficiently. In my program, I have a World class, which holds a 3D array of Region class pointers. When I initialize the world, I give it a width, height, and depth so it knows how large of a world to create. Each Region is split up into a 32x32x32 area of blocks, so as you may guess, it takes a while to initialize the world once the world gets to be above 8x4x8 Regions. In order to alleviate this issue, I thought that using threads to generate different levels of the world concurrently would make it go faster. Having not used threads much before this, and being still relatively new to C++, I'm not entirely sure how to go about implementing one thread per level (level being a xz plane with a height of 1), when there is a variable number of levels. I tried this: for(int i = 0; i < height; i++) { std::thread th(std::bind(&World::load, this, width, height, depth)); th.join(); } Where load() just loads all Regions at height "height". But that executes the threads one at a time (which makes sense, looking back), and that of course takes as long as generating all Regions in one loop. I then tried: std::thread t1(std::bind(&World::load, this, w, h1, h2 - 1, d)); std::thread t2(std::bind(&World::load, this, w, h2, h3 - 1, d)); std::thread t3(std::bind(&World::load, this, w, h3, h4 - 1, d)); std::thread t4(std::bind(&World::load, this, w, h4, h - 1, d)); t1.join(); t2.join(); t3.join(); t4.join(); This works in that the world loads about 3-3.5 times faster, but this forces the height to be a multiple of 4, and it also gives the same exact VAO object to every single Region, which need individual VAOs in order to render properly. The VAO of each Region is set in the constructor, so I'm assuming that somehow the VAO number is not thread safe or something (again, unfamiliar with threads). So basically, my question is two one-part: How to I implement a variable number of threads that all execute at the same time, and force the main thread to wait for them using join() without stopping the other threads? How do I make the VAO objects thread safe, so when a bunch of Regions are being created at the same time across multiple threads, they don't all get the exact same VAO? Turns out it has to do with GL contexts not working across multiple threads. I moved the VAO/VBO creation back to the main thread. Fixed! Here is the code for block.h/.cpp, region.h/.cpp, and CVBObject.h/.cpp which controls VBOs and VAOs, in case you need it. If you need to see anything else just ask. EDIT: Also, I'd prefer not to have answers that are like "you should have used boost". I'm trying to do this without boost to get used to threads before moving onto other libraries.

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• Creating a Corporate Data Hub

  - by BuckWoody

  The Windows Azure Marketplace has a rich assortment of data and software offerings for you to use – a type of Software as a Service (SaaS) for IT workers, not necessarily for end-users. Among those offerings is the “Data Hub” – a  codename for a project that ironically actually does what the codename says. In many of our organizations, we have multiple data quality issues. Finding data is one problem, but finding it just once is often a bigger problem. Lots of departments and even individuals have stored the same data more than once, and in some cases, made changes to one of the copies. It’s difficult to know which location or version of the data is authoritative. Then there’s the problem of accessing the data. It’s fairly straightforward to publish a database, share or other location internally to store the data. But then you have to figure out who owns it, how it is controlled, and pass out the various connection strings to those who want to use it. And then you need to figure out how to let folks access the internal data externally – bringing up all kinds of security issues. Finally, in many cases our user community wants us to combine data from the internally sources with external data, bringing up the security, strings, and exploration features up all over again. Enter the Data Hub. This is an online offering, where you assign an administrator and data stewards. You import the data into the service, and it’s available to you - and only you and your organization if you wish. The basic steps for this service are to set up the portal for your company, assign administrators and permissions, and then you assign data areas and import data into them. From there you make them discoverable, and then you have multiple options that you or your users can access that data. You’re then able, if you wish, to combine that data with other data in one location. So how does all that work? What about security? Is it really that easy? And can you really move the data definition off to the Subject Matter Experts (SME’s) that know the particular data stack better than the IT team does? Well, nothing good is easy – but using the Data Hub is actually pretty simple. I’ll give you a link in a moment where you can sign up and try this yourself. Once you sign up, you assign an administrator. From there you’ll create data areas, and then use a simple interface to bring the data in. All of this is done in a portal interface – nothing to install, configure, update or manage. After the data is entered in, and you’ve assigned meta-data to describe it, your users have multiple options to access it. They can simply use the portal – which actually has powerful visualizations you can use on any platform, even mobile phones or tablets.     Your users can also hit the data with Excel – which gives them ultimate flexibility for display, all while using an authoritative, single reference for the data. Since the service is online, they can do this wherever they are – given the proper authentication and permissions. You can also hit the service with simple API calls, like this one from C#: http://msdn.microsoft.com/en-us/library/hh921924  You can make HTTP calls instead of code, and the data can even be exposed as an OData Feed. As you can see, there are a lot of options. You can check out the offering here: http://www.microsoft.com/en-us/sqlazurelabs/labs/data-hub.aspx and you can read the documentation here: http://msdn.microsoft.com/en-us/library/hh921938

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• Consolidation in a Database Cloud

  - by B R Clouse

  Consolidation of multiple databases onto a shared infrastructure is the next step after Standardization.  The potential consolidation density is a function of the extent to which the infrastructure is shared.  The three models provide increasing degrees of sharing: Server: each database is deployed in a dedicated VM. Hardware is shared, but most of the software infrastructure is not. Standardization is often applied incompletely since operating environments can be moved as-is onto the shared platform. The potential for VM sprawl is an additional downside. Database: multiple database instances are deployed on a shared software / hardware infrastructure. This model is very efficient and easily implemented with the features in the Oracle Database and supporting products. Many customers have moved to this model and achieved significant, measurable benefits. Schema: multiple schemas are deployed within a single database instance. The most efficient model, it places constraints on the environment. Usually this model will be implemented only by customers deploying their own applications.  (Note that a single deployment can combine Database and Schema consolidations.) Customer value: lower costs, better system utilization In this phase of the maturity model, under-utilized hardware can be used to host more workloads, or retired and those workloads migrated to consolidation platforms. Customers benefit from higher utilization of the hardware resources, resulting in reduced data center floor space, and lower power and cooling costs. And, the OpEx savings from Standardization are multiplied, since there are fewer physical components (both hardware and software) to manage. Customer value: higher productivity The OpEx benefits from Standardization are compounded since not only are there fewer types of things to manage, now there are fewer entities to manage. In this phase, customers discover that their IT staff has time to move away from "day-to-day" tasks and start investing in higher value activities. Database users benefit from consolidating onto shared infrastructures by relieving themselves of the requirement to maintain their own dedicated servers. Also, if the shared infrastructure offers capabilities such as High Availability / Disaster Recovery, which are often beyond the budget and skillset of a standalone database environment, then moving to the consolidation platform can provide access to those capabilities, resulting in less downtime. Capabilities / Characteristics In this phase, customers will typically deploy fixed-size clusters and consolidate on a cluster until that cluster is deemed "full," at which point a new cluster is built. Customers will define one or a few cluster architectures that are used wherever possible; occasionally there may be deployments which must be handled as exceptions. The "full" policy may be based on number of databases deployed on the cluster, or observed peak workload, etc. IT will own the provisioning of new databases on a cluster, making the decision of when and where to place new workloads. Resources may be managed dynamically, e.g., as a priority workload increases, it may be given more CPU and memory to handle the spike. Users will be charged at a fixed, relatively coarse level; or in some cases, no charging will be applied. Activities / Tasks Oracle offers several tools to plan a successful consolidation. Real Application Testing (RAT) has a feature to help plan and validate database consolidations. Enterprise Manager 12c's Cloud Management Pack for Database includes a planning module. Looking ahead, customers should start planning for the Services phase by defining the Service Catalog that will be made available for database services.

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• Editing files without race conditions?

  - by user2569445

  I have a CSV file that needs to be edited by multiple processes at the same time. My question is, how can I do this without introducing race conditions? It's easy to write to the end of the file without race conditions by open(2)ing it in "a" (O_APPEND) mode and simply write to it. Things get more difficult when removing lines from the file. The easiest solution is to read the file into memory, make changes to it, and overwrite it back to the file. If another process writes to it after it is in memory, however, that new data will be lost upon overwriting. To further complicate matters, my platform does not support POSIX record locks, checking for file existence is a race condition waiting to happen, rename(2) replaces the destination file if it exists instead of failing, and editing files in-place leaves empty bytes in it unless the remaining bytes are shifted towards the beginning of the file. My idea for removing a line is this (in pseudocode): filename = "/home/user/somefile"; file = open(filename, "r"); tmp = open(filename+".tmp", "ax") || die("could not create tmp file"); //"a" is O_APPEND, "x" is O_EXCL|O_CREAT while(write(tmp, read(file)); //copy the $file to $file+".new" close(file); //edit tmp file unlink(filename) || die("could not unlink file"); file = open(filename, "wx") || die("another process must have written to the file after we copied it."); //"w" is overwrite, "x" is force file creation while(write(file, read(tmp))); //copy ".tmp" back to the original file unlink(filename+".tmp") || die("could not unlink tmp file"); Or would I be better off with a simple lock file? Appender process: lock = open(filename+".lock", "wx") || die("could not lock file"); file = open(filename, "a"); write(file, "stuff"); close(file); close(lock); unlink(filename+".lock"); Editor process: lock = open(filename+".lock", "wx") || die("could not lock file"); file = open(filename, "rw"); while(contents += read(file)); //edit "contents" write(file, contents); close(file); close(lock); unlink(filename+".lock"); Both of these rely on an additional file that will be left over if a process terminates before unlinking it, causing other processes to refuse to write to the original file. In my opinion, these problems are brought on by the fact that the OS allows multiple writable file descriptors to be opened on the same file at the same time, instead of failing if a writable file descriptor is already open. It seems that O_CREAT|O_EXCL is the closest thing to a real solution for preventing filesystem race conditions, aside from POSIX record locks. Another possible solution is to separate the file into multiple files and directories, so that more granular control can be gained over components (lines, fields) of the file using O_CREAT|O_EXCL. For example, "file/$id/$field" would contain the value of column $field of the line $id. It wouldn't be a CSV file anymore, but it might just work. Yes, I know I should be using a database for this as databases are built to handle these types of problems, but the program is relatively simple and I was hoping to avoid the overhead. So, would any of these patterns work? Is there a better way? Any insight into these kinds of problems would be appreciated.

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• Hibernate + PostgreSQL : relation does not exist - SQL Error: 0, SQLState: 42P01

  - by tommy599

  Hello, I am having some problems trying to work with PostgreSQL and Hibernate, more specifically, the issue mentioned in the title. I've been searching the net for a few hours now but none of the found solutions worked for me. I am using Eclipse Java EE IDE for Web Developers. Build id: 20090920-1017 with HibernateTools, Hibernate 3, PostgreSQL 8.4.3 on Ubuntu 9.10. Here are the relevant files: Message.class package hello; public class Message { private Long id; private String text; public Message() { } public Long getId() { return id; } public void setId(Long id) { this.id = id; } public String getText() { return text; } public void setText(String text) { this.text = text; } } Message.hbm.xml <?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping package="hello"> <class name="Message" table="public.messages"> <id name="id" column="id"> <generator class="assigned"/> </id> <property name="text" column="messagetext"/> </class> </hibernate-mapping> hibernate.cfg.xml <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> <hibernate-configuration> <session-factory> <property name="hibernate.connection.driver_class">org.postgresql.Driver</property> <property name="hibernate.connection.password">bar</property> <property name="hibernate.connection.url">jdbc:postgresql:postgres/tommy</property> <property name="hibernate.connection.username">foo</property> <property name="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</property> <property name="show_sql">true</property> <property name="log4j.logger.org.hibernate.type">DEBUG</property> <mapping resource="hello/Message.hbm.xml"/> </session-factory> </hibernate-configuration> Main package hello; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.Transaction; import org.hibernate.cfg.Configuration; public class App { public static void main(String[] args) { SessionFactory sessionFactory = new Configuration().configure() .buildSessionFactory(); Message message = new Message(); message.setText("Hello Cruel World"); message.setId(2L); Session session = null; Transaction transaction = null; try { session = sessionFactory.openSession(); transaction = session.beginTransaction(); session.save(message); } catch (Exception e) { System.out.println("Exception attemtping to Add message: " + e.getMessage()); } finally { if (session != null && session.isOpen()) { if (transaction != null) transaction.commit(); session.flush(); session.close(); } } } } Table structure: foo=# \d messages Table "public.messages" Column | Type | Modifiers -------------+---------+----------- id | integer | messagetext | text | Eclipse console output when I run it Apr 28, 2010 11:13:53 PM org.hibernate.cfg.Environment <clinit> INFO: Hibernate 3.5.1-Final Apr 28, 2010 11:13:53 PM org.hibernate.cfg.Environment <clinit> INFO: hibernate.properties not found Apr 28, 2010 11:13:53 PM org.hibernate.cfg.Environment buildBytecodeProvider INFO: Bytecode provider name : javassist Apr 28, 2010 11:13:53 PM org.hibernate.cfg.Environment <clinit> INFO: using JDK 1.4 java.sql.Timestamp handling Apr 28, 2010 11:13:53 PM org.hibernate.cfg.Configuration configure INFO: configuring from resource: /hibernate.cfg.xml Apr 28, 2010 11:13:53 PM org.hibernate.cfg.Configuration getConfigurationInputStream INFO: Configuration resource: /hibernate.cfg.xml Apr 28, 2010 11:13:53 PM org.hibernate.cfg.Configuration addResource INFO: Reading mappings from resource : hello/Message.hbm.xml Apr 28, 2010 11:13:54 PM org.hibernate.cfg.HbmBinder bindRootPersistentClassCommonValues INFO: Mapping class: hello.Message -> public.messages Apr 28, 2010 11:13:54 PM org.hibernate.cfg.Configuration doConfigure INFO: Configured SessionFactory: null Apr 28, 2010 11:13:54 PM org.hibernate.connection.DriverManagerConnectionProvider configure INFO: Using Hibernate built-in connection pool (not for production use!) Apr 28, 2010 11:13:54 PM org.hibernate.connection.DriverManagerConnectionProvider configure INFO: Hibernate connection pool size: 20 Apr 28, 2010 11:13:54 PM org.hibernate.connection.DriverManagerConnectionProvider configure INFO: autocommit mode: false Apr 28, 2010 11:13:54 PM org.hibernate.connection.DriverManagerConnectionProvider configure INFO: using driver: org.postgresql.Driver at URL: jdbc:postgresql:postgres/tommy Apr 28, 2010 11:13:54 PM org.hibernate.connection.DriverManagerConnectionProvider configure INFO: connection properties: {user=foo, password=****} Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: RDBMS: PostgreSQL, version: 8.4.3 Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: JDBC driver: PostgreSQL Native Driver, version: PostgreSQL 8.4 JDBC4 (build 701) Apr 28, 2010 11:13:54 PM org.hibernate.dialect.Dialect <init> INFO: Using dialect: org.hibernate.dialect.PostgreSQLDialect Apr 28, 2010 11:13:54 PM org.hibernate.engine.jdbc.JdbcSupportLoader useContextualLobCreation INFO: Disabling contextual LOB creation as createClob() method threw error : java.lang.reflect.InvocationTargetException Apr 28, 2010 11:13:54 PM org.hibernate.transaction.TransactionFactoryFactory buildTransactionFactory INFO: Using default transaction strategy (direct JDBC transactions) Apr 28, 2010 11:13:54 PM org.hibernate.transaction.TransactionManagerLookupFactory getTransactionManagerLookup INFO: No TransactionManagerLookup configured (in JTA environment, use of read-write or transactional second-level cache is not recommended) Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: Automatic flush during beforeCompletion(): disabled Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: Automatic session close at end of transaction: disabled Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: JDBC batch size: 15 Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: JDBC batch updates for versioned data: disabled Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: Scrollable result sets: enabled Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: JDBC3 getGeneratedKeys(): enabled Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: Connection release mode: auto Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: Default batch fetch size: 1 Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: Generate SQL with comments: disabled Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: Order SQL updates by primary key: disabled Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: Order SQL inserts for batching: disabled Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory createQueryTranslatorFactory INFO: Query translator: org.hibernate.hql.ast.ASTQueryTranslatorFactory Apr 28, 2010 11:13:54 PM org.hibernate.hql.ast.ASTQueryTranslatorFactory <init> INFO: Using ASTQueryTranslatorFactory Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: Query language substitutions: {} Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: JPA-QL strict compliance: disabled Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: Second-level cache: enabled Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: Query cache: disabled Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory createRegionFactory INFO: Cache region factory : org.hibernate.cache.impl.NoCachingRegionFactory Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: Optimize cache for minimal puts: disabled Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: Structured second-level cache entries: disabled Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: Echoing all SQL to stdout Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: Statistics: disabled Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: Deleted entity synthetic identifier rollback: disabled Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: Default entity-mode: pojo Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: Named query checking : enabled Apr 28, 2010 11:13:54 PM org.hibernate.cfg.SettingsFactory buildSettings INFO: Check Nullability in Core (should be disabled when Bean Validation is on): enabled Apr 28, 2010 11:13:54 PM org.hibernate.impl.SessionFactoryImpl <init> INFO: building session factory Apr 28, 2010 11:13:55 PM org.hibernate.impl.SessionFactoryObjectFactory addInstance INFO: Not binding factory to JNDI, no JNDI name configured Hibernate: insert into public.messages (messagetext, id) values (?, ?) Apr 28, 2010 11:13:55 PM org.hibernate.util.JDBCExceptionReporter logExceptions WARNING: SQL Error: 0, SQLState: 42P01 Apr 28, 2010 11:13:55 PM org.hibernate.util.JDBCExceptionReporter logExceptions SEVERE: Batch entry 0 insert into public.messages (messagetext, id) values ('Hello Cruel World', '2') was aborted. Call getNextException to see the cause. Apr 28, 2010 11:13:55 PM org.hibernate.util.JDBCExceptionReporter logExceptions WARNING: SQL Error: 0, SQLState: 42P01 Apr 28, 2010 11:13:55 PM org.hibernate.util.JDBCExceptionReporter logExceptions SEVERE: ERROR: relation "public.messages" does not exist Position: 13 Apr 28, 2010 11:13:55 PM org.hibernate.event.def.AbstractFlushingEventListener performExecutions SEVERE: Could not synchronize database state with session org.hibernate.exception.SQLGrammarException: Could not execute JDBC batch update at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:92) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66) at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:275) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:179) at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321) at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51) at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1206) at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:375) at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137) at hello.App.main(App.java:31) Caused by: java.sql.BatchUpdateException: Batch entry 0 insert into public.messages (messagetext, id) values ('Hello Cruel World', '2') was aborted. Call getNextException to see the cause. at org.postgresql.jdbc2.AbstractJdbc2Statement$BatchResultHandler.handleError(AbstractJdbc2Statement.java:2569) at org.postgresql.core.v3.QueryExecutorImpl$1.handleError(QueryExecutorImpl.java:459) at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1796) at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:407) at org.postgresql.jdbc2.AbstractJdbc2Statement.executeBatch(AbstractJdbc2Statement.java:2708) at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:70) at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:268) ... 8 more Exception in thread "main" org.hibernate.exception.SQLGrammarException: Could not execute JDBC batch update at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:92) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66) at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:275) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:179) at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321) at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51) at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1206) at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:375) at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137) at hello.App.main(App.java:31) Caused by: java.sql.BatchUpdateException: Batch entry 0 insert into public.messages (messagetext, id) values ('Hello Cruel World', '2') was aborted. Call getNextException to see the cause. at org.postgresql.jdbc2.AbstractJdbc2Statement$BatchResultHandler.handleError(AbstractJdbc2Statement.java:2569) at org.postgresql.core.v3.QueryExecutorImpl$1.handleError(QueryExecutorImpl.java:459) at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1796) at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:407) at org.postgresql.jdbc2.AbstractJdbc2Statement.executeBatch(AbstractJdbc2Statement.java:2708) at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:70) at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:268) ... 8 more PostgreSQL log file 2010-04-28 23:13:55 EEST LOG: execute S_1: BEGIN 2010-04-28 23:13:55 EEST ERROR: relation "public.messages" does not exist at character 13 2010-04-28 23:13:55 EEST STATEMENT: insert into public.messages (messagetext, id) values ($1, $2) 2010-04-28 23:13:55 EEST LOG: unexpected EOF on client connection If I copy/paste the query into the postgre command line and put the values in and ; after it, it works. Everything is lowercase, so I don't think that it's that issue. If I switch to MySQL, the same code same project (I only change driver,URL, authentication), it works. In Eclipse Datasource Explorer, I can ping the DB and it succeeds. Weird thing is that I can't see the tables from there either. It expands the public schema but it doesn't expand the tables. Could it be some permission issue? Thanks!

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• DRY Validation with MVC2

  - by Matthew

  Hi All, I'm trying to figure out how I can define validation rules for my domain objects in one single location within my application but have run in to a snag... Some background: My location has several parts: - Database - DAL - Business Logic Layer - SOAP API Layer - MVC website The MVC website accesses the database via the SOAP API, just as third parties would. We are using server and and client side validation on the MVC website as well as in the SOAP API Layer. To avoid having to manually write client side validation we are implementing strongly typed views in conjunction with the Html.TextBoxFor and Html.ValidationMessageFor HTML helpers, as shown in Step 3 here. We also create custom models for each form where one form takes input for multiple domain objects. This is where the problem begins, the HTML helpers read from the model for the data annotation validation attributes. In most cases our forms deal with multiple domain objects and you can't specify more than one type in the <%@Page ... Inherits="System.Web.Mvc.ViewPage" % page directive. So we are forced to create a custom model class, which would mean duplicating validation attributes from the domain objects on to the model class. I've spent quite some time looking for workarounds to this, such has referencing the same MetadataType from both the domain class and the custom MVC models, but that won't work for several reasons: You can only specify one MetadataType attribute per class, so its a problem if a model references multiple domain objects, each with their own metadata type. The data annotation validation code throws an exception if the model class doesn't contain a property that is specified in the referenced MetadataType which is a problem with the model only deals with a subset of the properties for a given domain object. I've looked at other solutions as well but to no avail. If anyone has any ideas on how to achieve a single source for validation logic that would work across MVC client and server side validation functionality and other locations (such as my SOAP API) I would love to hear it! Thanks in advance, Matthew

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• Self hosted WCF ServiceHost/WebServiceHost Concurrency/Peformance Design Options (.NET 3.5)

  - by Kyle

  So I'll be providing a few functions via a self hosted (in a WindowsService) WebServiceHost (not sure how to process HTTP GET/POST with ServiceHost), one of which may be called a large amount of the time. This function will also rely on a connection in the appdomain (hosted by the WindowsService so it can stay alive over multiple requests). I have the following concerns and would be oh so thankful for any input/thoughts/comments: Concurrent access - how does the WebServiceHost handle a bunch of concurrent requests. Are they queued and processes sequentially or are new instances of the contracts automagically created? WebServiceHost - WindowsService communication - I need some form of communication from the WebServiceHost to the hosting WindowsService for things like requesting a new session if one does not exist. Perhaps implementing a class which extends the WebServiceHost with events which the WindowsService subscribes to... (unless there is another way I can set off an event in the WindowsService when a request is made...) Multiple WebServiceHosts or Contracts - Would it give any real performance gain to be running multiple WebServiceHost instances in different threads (one per endpoint perhaps?) - A better understanding of the first point would probably help here. WSDL - I'm not sure why (probably just need to do more reading), but I'm not sure how to get the WebServiceHost base endpoint to respond with a WDSL document describing the available contract. Not required as all the operations will be done via GET requests which will not likely change, but it would be nice to have... That's about it for the moment ;) I've been reading a lot on WCF and wish I'd gotten into it long ago, but definitely still learning.

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• Object Oriented PHP Best Practices

  - by user270797

  Say I have a class which represents a person, a variable within that class would be $name. Previously, In my scripts I would create an instance of the object then set the name by just using: $object->name = "x"; However, I was told this was not best practice? That I should have a function set_name() or something similar like this: function set_name($name) { $this->name=$name; } is this correct? If in this example I want to insert a new "person" record into the db, how do I pass all the information about the person ie $name, $age, $address, $phone etc to the class in order to insert it, should I do: function set($data) { $this->name= $data['name']; $this->age = $data['age']; etc etc } Then send it an array? Would this be best practice? or could someone please recommend best practice?

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• LLBLGen - DeleteMulti

  - by Neil

  I have a checkboxlist of categories, during an update, I am trying to delete all the items in list from the associate table, then insert them all (so I don't have to determine if an item already exists in the associate table and only insert newly checked items). Here is the code I have: // First we need to delete the records from ArticleTopicCategory where articleId is the id of the article we are updating List<Guid> categoriesToDelete = new List<Guid>(); foreach (Guid category in this.View.SelectedCategories) { categoriesToDelete.Add(category); } ArticleTopicCategoryCollection articleCategories = new ArticleTopicCategoryCollection(); PredicateExpression filter = new PredicateExpression(ArticleTopicCategoryFields.Id == categoriesToDelete); articleCategories.DeleteMulti(filter); 'categoriesToDelete' holds a valid list of Guid's that need to be deleted, but they are not being deleted. Thanks in advance!

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• HttpRuntime.Cache scavenging default behavior?

  - by Rire1979

  When adding items using the default insert method Insert(key, value) and as such using the default behavior of HttpRuntime.Cache, when does the scavenging take place? The limit on the application pool that hosts my application is 0 (unlimited)... but I see no way to find out how big the cache can get before scavenging occurs? The problem is I am caching a potentially very large amount of data but I have limited memory on the server and I want to avoid recycling of the app pool. I am asking in the context of IIS6 and IIS7. Thank you.

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• PDF Manipulation with Adobe's Form Input Fields

  - by Justin

  Hello, I am trying to simplify a process where I currently use my hand calculations of X & Y Co-Ordinates of each value. Which works fine, but is causing me a lot of pain as I have to do quite a number of PDF's. I know that I can open a PDF and insert "input fields" within Adobe Acrobat Pro, which it would be great if I could use PHP to connect to those input fields and insert a value from a PHP Form. WORKFLOW:: PHP FORM PHP PROCESSING ENGINE TO FINAL PDF WITH FORM VALUES IN THE LOCATION OF THE ADOBE INPUT FIELDS. If someone has some information on something like this it would be much appreciated.

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• MS Access 2003: Can data disappear from records and how do I test for this and prevent it?

  - by user328960

  Problem and about the database: Data from a record in Access 2003 database has disappeared. This database has 1 backend and 3 frontends, multiple users and is hosted on Citrix. Within this database, we have records of all clients served, ranging in the 1000s. Background info: The form for client data entry is set up with various subforms, including both a "programs enrolled" subform and a "services" subform. A client can be enrolled in multiple programs. Once enrolled in a program, services can be entered for that program area using the services subform. There are multiple fields in the services subform, one of which is a drop-down field allowing you to choose from the programs a client has been enrolled in (the list is updated for that client whenever he is enrolled in a new program). The problem details: For one specific record and one specific program area, the program has disappeared from the "programs enrolled" subform and all of the related services have disappeared from the "services" subform for a period of 3 months of data entry. However, other programs and services for this record did not disappear. Questions: Is the disappearance of data a common Access 2003 problem? Are there tests in place that can be run to see if data is disappearing and catch that data? If so, what are they? If there is specific code involved, what is it? What can be done to prevent the disappearing of data (other than using a different database)?

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• From AutoComplete textbox to database search and display?

  - by svebee

  Hello everyone, I have a small problem so I would be grateful if anyone could help me in any way. Thank you ;) I have this little "application", and I want when someone type in a AutoComplete textbox for example "New" it automatically displays "New York" as a option and that (AutoComplete function) works fine. But I want when user type in full location (or AutoComplete do it for him) - that text (location) input is forwarded to a database search which then searches through database and "collects" all rows with user-typed location. For example if user typed in "New York", database search would find all rows with "New York" in it. When it finds one/more row(s) it would display them below. In images... I have this when user is typing... http://www.imagesforme.com/show.php/1093305_SNAG0000.jpg I have this when user choose a AutoComplete location (h)ttp://www.imagesforme.com/show.php/1093306_SNAG0001.jpg (remove () on the beggining) But I wanna this when user choose a AutoComplete location (h)ttp://www.imagesforme.com/show.php/1093307_CopyofSNAG0001.jpg (remove () on the beggining) Complete Code package com.svebee.prijevoz; import android.app.Activity; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.os.Bundle; import android.util.Log; import android.widget.ArrayAdapter; import android.widget.AutoCompleteTextView; import android.widget.TextView; public class ZelimDoci extends Activity { TextView lista; static final String[] STANICE = new String[] { "New York", "Chicago", "Dallas", "Los Angeles" }; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.zelimdoci); AutoCompleteTextView textView = (AutoCompleteTextView) findViewById(R.id.autocomplete_country); ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, R.layout.list_item, STANICE); textView.setAdapter(adapter); lista = (TextView)findViewById(R.id.lista); SQLiteDatabase myDB= null; String TableName = "Database"; String Data=""; /* Create a Database. */ try { myDB = this.openOrCreateDatabase("Database", MODE_PRIVATE, null); /* Create a Table in the Database. */ myDB.execSQL("CREATE TABLE IF NOT EXISTS " + TableName + " (Field1 INT(3) UNIQUE, Field2 INT(3) UNIQUE, Field3 VARCHAR UNIQUE, Field4 VARCHAR UNIQUE);"); Cursor a = myDB.rawQuery("SELECT * FROM Database where Field1 == 1", null); a.moveToFirst(); if (a == null) { /* Insert data to a Table*/ myDB.execSQL("INSERT INTO " + TableName + " (Field1, Field2, Field3, Field4)" + " VALUES (1, 119, 'New York', 'Dallas');"); myDB.execSQL("INSERT INTO " + TableName + " (Field1, Field2, Field3, Field4)" + " VALUES (9, 587, 'California', 'New York');"); } myDB.execSQL("INSERT INTO " + TableName + " (Field1, Field2, Field3, Field4)" + " VALUES (87, 57, 'Canada', 'London');"); } /*retrieve data from database */ Cursor c = myDB.rawQuery("SELECT * FROM " + TableName , null); int Column1 = c.getColumnIndex("Field1"); int Column2 = c.getColumnIndex("Field2"); int Column3 = c.getColumnIndex("Field3"); int Column4 = c.getColumnIndex("Field4"); // Check if our result was valid. c.moveToFirst(); if (c != null) { // Loop through all Results do { String LocationA = c.getString(Column3); String LocationB = c.getString(Column4); int Id = c.getInt(Column1); int Linija = c.getInt(Column2); Data =Data +Id+" | "+Linija+" | "+LocationA+"-"+LocationB+"\n"; }while(c.moveToNext()); } lista.setText(String.valueOf(Data)); } catch(Exception e) { Log.e("Error", "Error", e); } finally { if (myDB != null) myDB.close(); } } } .xml file <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" > <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:textSize="20sp" android:gravity="center_horizontal" android:padding="10sp" android:text="Test AutoComplete"/> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="wrap_content" android:padding="5dp"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="AutoComplete" /> <AutoCompleteTextView android:id="@+id/autocomplete_country" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_marginLeft="5dp"/> </LinearLayout> </LinearLayout>

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• php doctrine last identifier issue

  - by mike

  I'm running in to the issue below when trying to run the following: $store = new Store(); $store->url =$this->form_validation->set_value('website'); $store->save(); $store_id = $store->identifier(); Fatal error: Uncaught exception 'Doctrine_Connection_Exception' with message 'Couldn't get last insert identifier.' in /home/yummm/public_html/system/application/plugins/doctrine/lib/Doctrine/Connection/UnitOfWork.php:932 Stack trace: #0 /home/yummm/public_html/system/application/plugins/doctrine/lib/Doctrine/Connection/UnitOfWork.php(632): Doctrine_Connection_UnitOfWork->_assignIdentifier(Object(Category_store_assn)) #1 /home/yummm/public_html/system/application/plugins/doctrine/lib/Doctrine/Connection/UnitOfWork.php(562): Doctrine_Connection_UnitOfWork->processSingleInsert(Object(Category_store_assn)) #2 /home/yummm/public_html/system/application/plugins/doctrine/lib/Doctrine/Connection/UnitOfWork.php(81): Doctrine_Connection_UnitOfWork->insert(Object(Category_store_assn)) #3 /home/yummm/public_html/system/application/plugins/doctrine/lib/Doctrine/Record.php(1691): Doctrine_Connection_UnitOfWork->saveGraph(Object(Category_store_assn)) #4 /home/yummm/public_html/system/application/controllers/auth.php(375): Doctrine_Reco in /home/yummm/public_html/system/application/plugins/doctrine/lib/Doctrine/Connection/UnitOfWork.php on line 932 When I echo $store_id, it seems to be grabbing the last id without any issues. Any idea why this error keeps coming up even though the ID is passing correctly?

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• mySQL auto increment problem: Duplicate entry '4294967295' for key 1

  - by Josh

  I have a table of emails. The last record in there for an auto increment id is 3780, which is a legit record. Any new record I now insert is being inserted right there. However, in my logs I have the occasional: Query FAIL: INSERT INTO mail.messages (timestamp_queue) VALUES (:time); Array ( [0] => 23000 [1] => 1062 [2] => Duplicate entry '4294967295' for key 1 ) Somehow, the autoincrement jumped up to the INT max of 4294967295 Why on god's green earth would this get jumped up so high? I have no inserts with an id field. The show status for that table, Auto_increment table now reads: 4294967296 How could something like this occur? I realize the id field should perhaps be a big int, but the worry I have is that somehow this thing jumps back up. Josh

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• Emacs: selective c-auto-newline

  - by Yktula

  When c-auto-newline is set to non-nil, it re-indents the current line and inserts a carriage return and then indents the new line. However. I'm using 1TBS indent-style, which means if/else statements are made like this: if (n == 1) { exit(EXIT_SUCCESS); } else { perror("n"); } Also, I write do/while write loops like this: do { printf("%d\n", n++); } while (n < 64); As such, while I do want a newline automatically inserted after every opening brace and semicolon, I don't want newlines to be automatically inserted after an if statement or do loop is concluded with a closing brace. How can I have GNU Emacs (23.2.1, *nix) selectively insert newlines like that? Along the same lines, can I have Emacs insert an opening brace, a newline, and a closing brace on another newline, while putting the cursor in the middle of the two braces after closing parentheses following an if statement, function declaration, and the like?

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• NetBeans behaves differently if project is run via "Run Project" or build.xml>run

  - by Rogach

  I slightly modified the build-impl.xml file of my NetBeans project. (Specifically, I made it to insert build time into program code). If I run project via build.xml "run" target, I get behavior I expect - the program displays build time and date. But if I run project using standard (and most obvious, used it always) button "Run Main Project", I get totally another result (no build date). Moreover, if I insert any code into build.xml, I still get result if I run the target explicitly and no result if it is run simply by NetBeans. And this leads me to conclusion, that this button uses another method to run my application. My question is: what does that button do? What method does it call? And can it be configured to run the needed target of make file?

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• Fluid CSS: floating column with max-width and overflow

  - by Ates Goral

  I'm using a fluid layout in the new theme that I'm working on for my blog. I often blog about code and include <pre> blocks within the posts. The float: left column for the content area has a max-width so that the column stops at a certain maximum width and can also be shrunk: +----------+ +------+ | text | | text | | | | | | | | | | | | | | | | | | | | | +----------+ +------+ max shrunk What I want is for the <pre> elements to be wider than the text column so that I can fit 80-character-wrapped code without horizontal scroll bars. But I want the <pre> elements to overflow from the content area, without affecting its fluidity: +----------+ +------+ | text | | text | | | | | +----------+--+ +------+------+ | code | | code | +----------+--+ +------+------+ | | | | +----------+ +------+ max shrunk But, max-width stops being fluid once I insert the overhanging <pre> in there: the width of the column remains at the specified max-width even when I shrink the browser beyond that width. I've reproduced the issue with this bare-minimum scenario: <div style="float: left; max-width: 460px; border: 1px solid red"> <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit</p> <pre style="max-width: 700px; border: 1px solid blue"> function foo() { // Lorem ipsum dolor sit amet, consectetur adipisicing elit } </pre> <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit</p> </div> I noticed that doing either of the following brings back the fluidity: Remove the <pre> (doh...) Remove the float: left The workaround I'm currently using is to insert the <pre> elements into "breaks" in the post column, so that the widths of the post segments and the <pre> segments are managed mutually exclusively: +----------+ +------+ | text | | text | +----------+ +------+ +-------------+ +-------------+ | code | | code | +-------------+ +-------------+ +----------+ +------+ +----------+ +------+ max shrunk But this forces me to insert additional closing and opening <div> elements into the post markup which I'd rather keep semantically pristine. Admittedly, I don't have a full grasp of how the box model works with floats with overflowing content, so I don't understand why the combination of float: left on the container and the <pre> inside it cripple the max-width of the container. I'm observing the same problem on Firefox/Chrome/Safari/Opera. IE6 (the crazy one) seems happy all the time. This also doesn't seem dependent on quirks/standards mode. Update I've done further testing to observe that max-width seems to get ignored when the element has a float: left. I glanced at the W3C box model chapter but couldn't immediately see an explicit mention of this behaviour. Any pointers?

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• UnboundLocalError: local variable 'rows' referenced before assignment

  - by patrick

  i'm trying to make a database connection by an other script. But the script didn't work propperly. and if I do a 'print' on the rows then I get the value 'null' But if I use a 'select * from incidents' query then i get the result from the table incidents. import database rows = database.database("INSERT INTO incidents VALUES(3 ,'test_title1', 'test', TO_DATE('25-07-2012', 'DD-MM-YYYY'), CURRENT_TIMESTAMP, 'sector', 50, 60)") #print database.database() print rows database.py script: import psycopg2 import sys import logfile def database(query): logfile.log(20, 'database.py', 'Executing...') con = None try: con = psycopg2.connect(database='incidents', user='ipfit5', password='tester') cur = con.cursor() #print query cur.execute(query) rows = cur.fetchall() con.commit() #test row does work #cur.execute("INSERT INTO incidents VALUES(3 ,'test_titel1', 'test', TO_DATE('25-07-2012', 'DD-MM-YYYY'), CURRENT_TIMESTAMP, 'sector', 50, 60)") except: logfile.log(40, 'database.py', 'Er is iets mis gegaan') logfile.log(40, 'database.py', str(sys.exc_info())) finally: if con: con.close() return rows

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• add table row before or after a table row of known ID

  - by Perpetualcoder

  In a table like this: <table> <!-- Insert Row of bun here --> <tr id="meat"> <td>Hamburger</td> </tr/> <!-- Insert Row of bun here --> </table> function AddBefore(rowId){} function AddAfter(rowId){} I need to create methods without using jquery..i am familiar with append after and append before in jquery.. but i am stuck with using palin js.

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