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  • Optimising a query for Top 5% of users

    - by Nai
    On my website, there exists a group of 'power users' who are fantastic and adding lots of content on to my site. However, their prolific activities has led to their profile pages slowing down a lot. For 95% of the other users, the SPROC that is returning the data is very quick. It's only for these group of power users, the very same SPROC is slow. How does one go about optimising the query for this group of users? You can assume that the right indexes have already been constructed. EDIT: Ok, I think I have been a bit too vague. To rephrase the question, how can I optimise my site to enhance the performance for these 5% of users. Given that this SPROC is the same one that is in use for every user and that it is already well optimised, I am guessing the next steps are to explore caching possibilities on the data and application layers?

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  • SQL University: Database testing and refactoring tools and examples

    - by Mladen Prajdic
    This is a post for a great idea called SQL University started by Jorge Segarra also famously known as SqlChicken on Twitter. It’s a collection of blog posts on different database related topics contributed by several smart people all over the world. So this week is mine and we’ll be talking about database testing and refactoring. In 3 posts we’ll cover: SQLU part 1 - What and why of database testing SQLU part 2 - What and why of database refactoring SQLU part 3 - Database testing and refactoring tools and examples This is the third and last part of the series and in it we’ll take a look at tools we can test and refactor with plus some an example of the both. Tools of the trade First a few thoughts about how to go about testing a database. I'm firmily against any testing tools that go into the database itself or need an extra database. Unit tests for the database and applications using the database should all be in one place using the same technology. By using database specific frameworks we fragment our tests into many places and increase test system complexity. Let’s take a look at some testing tools. 1. NUnit, xUnit, MbUnit All three are .Net testing frameworks meant to unit test .Net application. But we can test databases with them just fine. I use NUnit because I’ve always used it for work and personal projects. One day this might change. So the thing to remember is to be flexible if something better comes along. All three are quite similar and you should be able to switch between them without much problem. 2. TSQLUnit As much as this framework is helpful for the non-C# savvy folks I don’t like it for the reason I stated above. It lives in the database and thus fragments the testing infrastructure. Also it appears that it’s not being actively developed anymore. 3. DbFit I haven’t had the pleasure of trying this tool just yet but it’s on my to-do list. From what I’ve read and heard Gojko Adzic (@gojkoadzic on Twitter) has done a remarkable job with it. 4. Redgate SQL Refactor and Apex SQL Refactor Neither of these refactoring tools are free, however if you have hardcore refactoring planned they are worth while looking into. I’ve only used the Red Gate’s Refactor and was quite impressed with it. 5. Reverting the database state I’ve talked before about ways to revert a database to pre-test state after unit testing. This still holds and I haven’t changed my mind. Also make sure to read the comments as they are quite informative. I especially like the idea of setting up and tearing down the schema for each test group with NHibernate. Testing and refactoring example We’ll take a look at the simple schema and data test for a view and refactoring the SELECT * in that view. We’ll use a single table PhoneNumbers with ID and Phone columns. Then we’ll refactor the Phone column into 3 columns Prefix, Number and Suffix. Lastly we’ll remove the original Phone column. Then we’ll check how the view behaves with tests in NUnit. The comments in code explain the problem so be sure to read them. I’m assuming you know NUnit and C#. T-SQL Code C# test code USE tempdbGOCREATE TABLE PhoneNumbers( ID INT IDENTITY(1,1), Phone VARCHAR(20))GOINSERT INTO PhoneNumbers(Phone)SELECT '111 222333 444' UNION ALLSELECT '555 666777 888'GO-- notice we don't have WITH SCHEMABINDINGCREATE VIEW vPhoneNumbersAS SELECT * FROM PhoneNumbersGO-- Let's take a look at what the view returns -- If we add a new columns and rows both tests will failSELECT *FROM vPhoneNumbers GO -- DoesViewReturnCorrectColumns test will SUCCEED -- DoesViewReturnCorrectData test will SUCCEED -- refactor to split Phone column into 3 partsALTER TABLE PhoneNumbers ADD Prefix VARCHAR(3)ALTER TABLE PhoneNumbers ADD Number VARCHAR(6)ALTER TABLE PhoneNumbers ADD Suffix VARCHAR(3)GO-- update the new columnsUPDATE PhoneNumbers SET Prefix = LEFT(Phone, 3), Number = SUBSTRING(Phone, 5, 6), Suffix = RIGHT(Phone, 3)GO-- remove the old columnALTER TABLE PhoneNumbers DROP COLUMN PhoneGO-- This returns unexpected results!-- it returns 2 columns ID and Phone even though -- we don't have a Phone column anymore.-- Notice that the data is from the Prefix column-- This is a danger of SELECT *SELECT *FROM vPhoneNumbers -- DoesViewReturnCorrectColumns test will SUCCEED -- DoesViewReturnCorrectData test will FAIL -- for a fix we have to call sp_refreshview -- to refresh the view definitionEXEC sp_refreshview 'vPhoneNumbers'-- after the refresh the view returns 4 columns-- this breaks the input/output behavior of the database-- which refactoring MUST NOT doSELECT *FROM vPhoneNumbers -- DoesViewReturnCorrectColumns test will FAIL -- DoesViewReturnCorrectData test will FAIL -- to fix the input/output behavior change problem -- we have to concat the 3 columns into one named PhoneALTER VIEW vPhoneNumbersASSELECT ID, Prefix + ' ' + Number + ' ' + Suffix AS PhoneFROM PhoneNumbersGO-- now it works as expectedSELECT *FROM vPhoneNumbers -- DoesViewReturnCorrectColumns test will SUCCEED -- DoesViewReturnCorrectData test will SUCCEED -- clean upDROP VIEW vPhoneNumbersDROP TABLE PhoneNumbers [Test]public void DoesViewReturnCoorectColumns(){ // conn is a valid SqlConnection to the server's tempdb // note the SET FMTONLY ON with which we return only schema and no data using (SqlCommand cmd = new SqlCommand("SET FMTONLY ON; SELECT * FROM vPhoneNumbers", conn)) { DataTable dt = new DataTable(); dt.Load(cmd.ExecuteReader(CommandBehavior.CloseConnection)); // test returned schema: number of columns, column names and data types Assert.AreEqual(dt.Columns.Count, 2); Assert.AreEqual(dt.Columns[0].Caption, "ID"); Assert.AreEqual(dt.Columns[0].DataType, typeof(int)); Assert.AreEqual(dt.Columns[1].Caption, "Phone"); Assert.AreEqual(dt.Columns[1].DataType, typeof(string)); }} [Test]public void DoesViewReturnCorrectData(){ // conn is a valid SqlConnection to the server's tempdb using (SqlCommand cmd = new SqlCommand("SELECT * FROM vPhoneNumbers", conn)) { DataTable dt = new DataTable(); dt.Load(cmd.ExecuteReader(CommandBehavior.CloseConnection)); // test returned data: number of rows and their values Assert.AreEqual(dt.Rows.Count, 2); Assert.AreEqual(dt.Rows[0]["ID"], 1); Assert.AreEqual(dt.Rows[0]["Phone"], "111 222333 444"); Assert.AreEqual(dt.Rows[1]["ID"], 2); Assert.AreEqual(dt.Rows[1]["Phone"], "555 666777 888"); }}   With this simple example we’ve seen how a very simple schema can cause a lot of problems in the whole application/database system if it doesn’t have tests. Imagine what would happen if some outside process would depend on that view. It would get wrong data and propagate it silently throughout the system. And that is not good. So have tests at least for the crucial parts of your systems. And with that we conclude the Database Testing and Refactoring week at SQL University. Hope you learned something new and enjoy the learning weeks to come. Have fun!

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  • How to archive data from a table to a local or remote database in SQL 2005 and SQL 2008

    - by simonsabin
    Often you have the need to archive data from a table. This leads to a number of challenges 1. How can you do it without impacting users 2. How can I make it transactionally consistent, i.e. the data I put in the archive is the data I remove from the main table 3. How can I get it to perform well Points 1 is very much tied to point 3. If it doesn't perform well then the delete of data is going to cause lots of locks and thus potentially blocking. For points 1 and 3 refer to my previous posts DELETE-TOP-x-rows-avoiding-a-table-scan and UPDATE-and-DELETE-TOP-and-ORDER-BY---Part2. In essence you need to be removing small chunks of data from your table and you want to do that avoiding a table scan. So that deals with the delete approach but archiving is about inserting that data somewhere else. Well in SQL 2008 they introduced a new feature INSERT over DML (Data Manipulation Language, i.e. SQL statements that change data), or composable DML. The ability to nest DML statements within themselves, so you can past the results of an insert to an update to a merge. I've mentioned this before here SQL-Server-2008---MERGE-and-optimistic-concurrency. This feature is currently limited to being able to consume the results of a DML statement in an INSERT statement. There are many restrictions which you can find here http://msdn.microsoft.com/en-us/library/ms177564.aspx look for the section "Inserting Data Returned From an OUTPUT Clause Into a Table" Even with the restrictions what we can do is consume the OUTPUT from a DELETE and INSERT the results into a table in another database. Note that in BOL it refers to not being able to use a remote table, remote means a table on another SQL instance. To show this working use this SQL to setup two databases foo and fooArchive create database foo go --create the source table fred in database foo select * into foo..fred from sys.objects go create database fooArchive go if object_id('fredarchive',DB_ID('fooArchive')) is null begin     select getdate() ArchiveDate,* into fooArchive..FredArchive from sys.objects where 1=2       end go And then we can use this simple statement to archive the data insert into fooArchive..FredArchive select getdate(),d.* from (delete top (1)         from foo..Fred         output deleted.*) d         go In this statement the delete can be any delete statement you wish so if you are deleting by ids or a range of values then you can do that. Refer to the DELETE-TOP-x-rows-avoiding-a-table-scan post to ensure that your delete is going to perform. The last thing you want to do is to perform 100 deletes each with 5000 records for each of those deletes to do a table scan. For a solution that works for SQL2005 or if you want to archive to a different server then you can use linked servers or SSIS. This example shows how to do it with linked servers. [ONARC-LAP03] is the source server. begin transaction insert into fooArchive..FredArchive select getdate(),d.* from openquery ([ONARC-LAP03],'delete top (1)                     from foo..Fred                     output deleted.*') d commit transaction and to prove the transactions work try, you should get the same number of records before and after. select (select count(1) from foo..Fred) fred        ,(select COUNT(1) from fooArchive..FredArchive ) fredarchive   begin transaction insert into fooArchive..FredArchive select getdate(),d.* from openquery ([ONARC-LAP03],'delete top (1)                     from foo..Fred                     output deleted.*') d rollback transaction   select (select count(1) from foo..Fred) fred        ,(select COUNT(1) from fooArchive..FredArchive ) fredarchive The transactions are very important with this solution. Look what happens when you don't have transactions and an error occurs   select (select count(1) from foo..Fred) fred        ,(select COUNT(1) from fooArchive..FredArchive ) fredarchive   insert into fooArchive..FredArchive select getdate(),d.* from openquery ([ONARC-LAP03],'delete top (1)                     from foo..Fred                     output deleted.*                     raiserror (''Oh doo doo'',15,15)') d                     select (select count(1) from foo..Fred) fred        ,(select COUNT(1) from fooArchive..FredArchive ) fredarchive Before running this think what the result would be. I got it wrong. What seems to happen is that the remote query is executed as a transaction, the error causes that to rollback. However the results have already been sent to the client and so get inserted into the

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  • HSSFS Part 3: SQL Saturday is Awesome! And DEFAULT_DOMAIN(), and how I found it

    - by Most Valuable Yak (Rob Volk)
    Just a quick post I should've done yesterday but I was recovering from SQL Saturday #48 in Columbia, SC, where I went to some really excellent sessions by some very smart experts.  If you have not yet attended a SQL Saturday, or its been more than 1 month since you last did, SIGN UP NOW! While searching the OBJECT_DEFINITION() of SQL Server system procedures I stumbled across the DEFAULT_DOMAIN() function in xp_grantlogin and xp_revokelogin.  I couldn't find any information on it in Books Online, and it's a very simple, self-explanatory function, but it could be useful if you work in a multi-domain environment.  It's also the kind of neat thing you can find by using this query: SELECT OBJECT_SCHEMA_NAME([object_id]) object_schema, name FROM sys.all_objects WHERE OBJECT_DEFINITION([object_id]) LIKE '%()%'  ORDER BY 1,2 I'll post some elaborations and enhancements to this query in a later post, but it will get you started exploring the functional SQL Server sea. UPDATE: I goofed earlier and said SQL Saturday #46 was in Columbia. It's actually SQL Saturday #48, and SQL Saturday #46 was in Raleigh, NC.

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  • T-SQL Tuesday #34: Help! I Need Somebody!

    - by Most Valuable Yak (Rob Volk)
    Welcome everyone to T-SQL Tuesday Episode 34!  When last we tuned in, Mike Fal (b|t) hosted Trick Shots.  These highlighted techniques or tricks that you figured out on your own which helped you understand SQL Server better. This month, I'm asking you to look back this past week, year, century, or hour...to a time when you COULDN'T figure it out.  When you were stuck on a SQL Server problem and you had to seek help. In the beginning... SQL Server has changed a lot since I started with it.  <Cranky Old Guy> Back in my day, Books Online was neither.  There were no blogs. Google was the third-place search site. There were perhaps two or three community forums where you could ask questions.  (Besides the Microsoft newsgroups...which you had to access with Usenet.  And endure the wrath of...Celko.)  Your "training" was reading a book, made from real dead trees, that you bought from your choice of brick-and-mortar bookstore. And except for your local user groups, there were no conferences, seminars, SQL Saturdays, or any online video hookups where you could interact with a person. You'd have to call Microsoft Support...on the phone...a LANDLINE phone.  And none of this "SQL Family" business!</Cranky Old Guy> Even now, with all these excellent resources available, it's still daunting for a beginner to seek help for SQL Server.  The product is roughly 1247.4523 times larger than it was 15 years ago, and it's simply impossible to know everything about it.*  So whether you are a beginner, or a seasoned pro of over a decade's experience, what do you do when you need help on SQL Server? That's so meta... In the spirit of offering help, here are some suggestions for your topic: Tell us about a person or SQL Server community who have been helpful to you.  It can be about a technical problem, or not, e.g. someone who volunteered for your local SQL Saturday.  Sing their praises!  Let the world know who they are! Do you have any tricks for using Books Online?  Do you use the locally installed product, or are you completely online with BOL/MSDN/Technet, and why? If you've been using SQL Server for over 10 years, how has your help-seeking changed? Are you using Twitter, StackOverflow, MSDN Forums, or another resource that didn't exist when you started? What made you switch? Do you spend more time helping others than seeking help? What motivates you to help, and how do you contribute? Structure your post along the lyrics to The Beatles song Help! Audio or video renditions are particularly welcome! Lyrics must include reference to SQL Server terminology or community, and performances must be in your voice or include you playing an instrument. These are just suggestions, you are free to write whatever you like.  Bonus points if you can incorporate ALL of these into a single post.  (Or you can do multiple posts, we're flexible like that.)  Help us help others by showing how others helped you! Legalese, Your Rights, Yada yada... If you would like to participate in T-SQL Tuesday please be sure to follow the rules below: Your blog post must be published between Tuesday, September 11, 2012 00:00:00 GMT and Wednesday, September 12, 2012 00:00:00 GMT. Include the T-SQL Tuesday logo (above) and hyperlink it back to this post. If you don’t see your post in trackbacks, add the link to the comments below. If you are on Twitter please tweet your blog using the #TSQL2sDay hashtag.  I can be contacted there as @sql_r, in case you have questions or problems with comments/trackback.  I'll have a follow-up post listing all the contributions as soon as I can. Thank you all for participating, and special thanks to Adam Machanic (b|t) for all his help and for continuing this series!

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  • LINQ to SQL Could not find key member. Only fails on server.

    - by Adam Carr
    I have a scenario where I am inheriting from an abstract class in my partial linq to sql auto generated class implementation. My base abstract class has an abstract property called ID which I have flagged inside my LINQ to SQL model with the instance modifier override. This works fine locally without any issues. I have also done some development on another machine and it works fine there too (both in VS2008 and using Subversion). I am running CI with TeamCity and the build succeeds and deploys as desired. The problem is when the server tries to hit the database for the first time via the LINQ to SQL data context, it generates the following error. "Could not find key member 'Id' of key 'Id' on type 'CustomType'. The key may be wrong or the field or property on 'CustomType' has changed names." I have tried changing my configuration by not implementing the Id field in my base class but this still fails. Why does it work on both of my DEV machines but not on the server? I am using LINQ to SQL in another project that runs on this server just fine. FYI: LINQ to SQL, SQL 2008, .NET 3.5, SERVER 2008, IIS 7.0 UPDATE I have gone back and added the same table a second time in the same data model but without a base class and have then displayed the results from that table and got no errors. This tells me it has something to do with my base abstract class and the need to flag a property on one of my linq to sql model classes (that belongs to a key relationship) with the instance modifier of override. No answer to this yet but am getting closer. UPDATE I have fixed my issue by simply changing my approach to my problem but I am still interested in why this doesn't work. I created a new WinSrv2008 VPC and patched it, deployed a pre-built version of my site to it and still got the same error. I now assume the issue is like what the person said here, a dependency issue with VS2008. My question is what or what? Will install VS2008 on the VPC to see if it works after that.

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  • New Computer Build Questions

    - by MJ
    I'm in the process of gathering parts and specs for a new machine. I wear many hats, so the machine needs to do a lot. I need at least 2 monitor support, if not three. I also play many online MMOs (wow, aion, war hammer, etc), along with some freelance programming projects. I already have a case which is very large, so it will fit anything. I have 2 other SATA HDs. They are more for storage and basic programs. I feel that the best improvement could be done with a solid state HD, true or not? I'm more of a software/programming guy, so ANY input at all on improving this system build would be appreciated. I have a few questions with this list. AMD or Intel? I don't know enough about either to choose what would best fit me. Thanks! **EDIT: Thanks for the input everyone! Here are some answers: I do a lot of programming and gaming, so I do need things for both. The newer video card covers the gaming aspect, as well as allowing me to have many monitors. (hopefully upgrade to dual 30' or more) I don't need any additional HDs at this time. I have a SATA 160g and 120g from my previous computer, and a NAS system with over 2TB of storage on the homenetwork. I just wanted a fast HD for OS/programs/games. With the memory. I have used G.SKILL before in 2 system builds. It's done excellent for me in them. Very stable. **EDIT2: Made some additional changes. Lowered the power supply down to 750, which saves me more $$. Also changed the SSD to 2 WD 650G HDs. Thinking of doing a CPU upgrade to the 3.4GHZ AMD Phenom II X4 965 Black Edition Deneb 3.4GHz System Specs - Budget:$1500 CPU: AMD Phenom II X4 955 Black Edition Deneb 3.2GHz MB: GIGABYTE GA-MA790GPT-UD3H AM3 AMD 790GX HDMI ATX Memory: G.SKILL 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 1066 Video: DIAMOND 5870PE51G Radeon HD 5870 (Cypress XT) 1GB 256-bit GD Power Supply: XCLIO GREATPOWER 1000W ATX12V SLI Ready CrossFire Ready HD:Intel X25-M Mainstream SSDSA2MH080G2C1 2.5" 80GB SATA II MLC Changes: Power Supply: CORSAIR CMPSU-750TX 750W ATX12V / EPS12V HD: 2x Western Digital Caviar Blue WD6400AAKS 640GB CPU: AMD Phenom II X4 965 Black Edition Deneb 3.4GHz

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  • Some questions regarding Hostname

    - by user481913
    I just bought a new VPS hosting plan and i have a few questions. Hope someone here can clear the doubts for me. 1) Is it necessary to have a real domain for a vps hostname? I suppose i can just use a non-real domain like anydomain.com and something like 'server' for the computer name. Therefore i'll end up with something like server.anydomain.com as the vps's hostname. I want to do this for the sake of putting in a hostname to configure the vps to get it going . So, since this non-real domain name does not need to be publicly accessible i don't need to register or own it and instead access the server by the ip address. Is that correct? But i suppose that this also depends upon if my web host allows that? 2)I would also like to run some real sites with real domain names on this vps, so can i just configure the zone file on the primary nameserver and make entries for these domains and point an A record at the Vps's IP to make them publicly accessible over the internet? For example for my 1st domain i could make an entry like this: $TTL 86400 mydomain1.com. IN SOA ns1.mywebhost.com. \ admin.mydomain1.com. ( 2004011522 ; Serial no., based on date 21600 ; Refresh after 6 hours 3600 ; Retry after 1 hour 604800 ; Expire after 7 days 3600 ; Minimum TTL of 1 hour ) server IN A 200._._._ ns1.mywebhost.com. IN A 216._._._ ns2.mywebhost.com. IN A 205._._._ @ IN NS ns1.mywebhost.com. @ IN NS ns2.mywebhost.com. @ IN MX 10 server www IN CNAME server server IN CNAME @ (so this particular line tells the nameserver to point the url mydomain1.com to server.anydomain.com at the particular ip addresss in the A record.... is that right?) Similarly for my 2nd domain i could have a similar entry : $TTL 86400 mydomain2.com. IN SOA ns1.mywebhost.com. \ admin.mydomain2.com. (..... ............................so on........ ......................................... ......................................... ......................................... ......................................... ......................................... Is that correct? 3) Suppose for my vps hostname, i ignorantly chose a domain that someone else alreadys owns , however i think that it won't affect the public accessibility of the real domain or website since only the real owner of the domain has the rights to provide for the nameservers addresses in the TLD registeries through his Domian Registerar? Is that correct? 4)Can i change my vps's hostname later? Would this create any complications?

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  • Questions every good PHP Developer should be able to answer

    - by Rachel
    I was going through Questions every good .Net developer should be able to answer and was highly impressed with the content and approach of this question and so in the same spirit, I am asking this question for PHP Developer. What questions do you think should a good PHP programmer be able to respond to? EDIT : I am marking this question as community wiki as it is not user specific and it aims to serve programming community at large. Looking forward for some amazing responses. NOTE : Please answer questions too as suggested in the comments so that people could learn something new too regarding the language.

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  • Where to ask practical unit-testing questions?

    - by Ian Boyd
    Before i can understand unit testing, i have to see real world examples. Every book, blog, article, or answer i've seen gives hypothetical examples that don't apply to the/my real world. i really don't want to flood StackOverflow with hundreds of questions all titled "How do i unit-test this?" There must be another place i can go to ask for real solutions. Where can i go to get practical answers to unit-testing questions? Note: i would give an example question, but then people would get grumpy when i asked the 200 follow-up questions.

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  • Where do you get ArcGIS development questions answered?

    - by nw
    Where do you have the most success getting your ArcGIS development questions answered? ESRI forums? Stack Overflow? Google? Mailing lists? Blog posts? ESRI documentation? I can usually get answers to my ASP.NET/Oracle/JavaScript/C# questions in short order, but questions about ESRI products and APIs are a different matter. Posts founder in the forums, Google returns void, etc. I'm sure this is not uncommon for niche commercial products, but frustrating nevertheless. What works for you? Please share.

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  • Software-related but not programming-specific questions

    - by jayrdub
    I have often fought the urge to ask questions that I know aren't appropriate on SO, because I personally haven't come across another online group who's opinions I would trust as much. What sites do you frequent that you have found good participation from a smart group of people where you can ask questions that are related to software, but not programming problems? This community also has a vast depth of knowledge about things related to software like marketing, graphics/UI, running a small business, working in bad jobs, etc. that would greatly benefit everyone else. Where do we go to tap all that knowledge? On stackoverflow.uservoice.com there is a popular suggested feature to sanction, or add to SO, a place to hold discussions that aren't about specific programming questions. It seems that the suggestion has been denied in the past though.

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  • start page with questions about interested tags?

    - by Stefan K.
    I'm new to stackoverflow and I'm looking for a question list, like the one on top, which just contains questions about interested tags. For example I'm interested in Java, but I have no clue about Python and questions about python clutters my questions page. I don't have answers concerning any python problem. I think it's too exhausting to enter my interested tags in the search combined with [xxx] OR. Is there a usable way to do this? By the way, what for are interested tags used right now? I added some in my profile but didn't see a benefit.

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  • sqlcmd won't execute - Claims Native Client not installed properly

    - by nuit9
    I'm trying to use sqlcmd to execute some SQL scripts. Using a test command with a simple query like: sqlcmd -S HOSTNAME -d MYDATABASE -Q 'SELECT Names FROM Customers' sqlcmd does not appear to make any attempt to connect to the server as it displays this message: Sqlcmd: Error: Connection failure. SQL Native Client is not installed correctly. To correct this, run SQL Server Setup. The native client was presumably installed as part of the SQL Server setup and likely correctly. I actually get this message on any machine with SQL server installed trying to use sqlcmd so it's not a matter of the installation being corrupt. Unfortunately the message really tells me nothing about the problem so I don't know what the real issue is. I know the SQL Native client is working properly since a vbscript was able to execute SQL queries against the database. Is there some additional configuration needed to use sqlcmd?

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  • Running SQL*Plus with bash causes wrong encoding

    - by Petr Mensik
    I have a problem with running SQL*Plus in the bash. Here is my code #!/bin/bash #curl http://192.168.168.165:8080/api_test/xsql/f_exp_order_1016.xsql > script.sql wget -O script.sql 192.168.168.165:8080/api_test/xsql/f_exp_order_1016.xsql set NLS_LANG=_.UTF8 sqlplus /nolog << ENDL connect login/password set sqlblanklines on start script.sql exit <<endl I download the insert statements from our intranet, put it into sql file and run it through SQL*Plus. This is working fine. My problem is that when I save the file script.sql my encoding goes wrong. All special characters(like íášc) are broken and that's causing inserting wrong characters into my DB. Encoding of that file is UTF-8, also UTF-8 is set on the XSQL page on our intranet. So I really don't know where could be a problem. And also any advices regarding to my script are welcomed, I am total newbie in Linux scripting:-)

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  • SQLIO help decipher output

    - by SQL Learner
    When load testing on a SQL Server Box, using following (testfile is 25 GB) sqlio -kW -t8 -s360 -o8 -frandom -b8 -BH -LS g:\testfile.dat > result.txt sqlio -kW -t8 -s360 -o8 -frandom -b64 -BH -LS g:\testfile.dat >> result.txt sqlio -kW -t8 -s360 -o8 -frandom -b128 -BH -LS g:\testfile.dat >> result.txt sqlio -kW -t8 -s360 -o8 -frandom -b256 -BH -LS g:\testfile.dat >> result.txt Can anyone help me decipher output.. I do not understand latency min and average....? What does this number means IOs/sec: 10968.80 MBs/sec: 685.55 latency metrics: Min_Latency(ms): 1 Avg_Latency(ms): 5 Max_Latency(ms): 21

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  • Exchange 2010 OWA - a few questions about using multiple mailboxes

    - by Alexey Smolik
    We have an Exchange 2010 SP2 deployment and we need that our users could access multiple mailboxes in OWA. The problem is that a user (eg John Smith) needs to access not just somebody else's (eg Tom Anderson) mailboxes, but his OWN mailboxes, e.g. in different domains: [email protected], [email protected], [email protected], etc. Of course it is preferable for the user to work with all of his mailboxes from a single window. Such mailboxes can be added as multiple Exchange accounts in Outlook, that works almost fine. But in OWA, there are problems: 1) In the left pane - as I've learned - we can open only Inbox folders from other mailboxes. No way to view all folders like in Outlook? 2) With Send-As permissions set, when trying to send a message from another address, that message is saved in the Sent Items folder of the mailbox that is opened in OWA, and not in the mailbox the message is sent from. The same thing with the trash can. Is there a way to fix that? Also, this problem exists in desktop Outlook when mailboxes are added automatically via the Auto Mapping feature, so that we need to turn it off and add the accounts manually. Is there a simpler workaround? 3) Okay, suppose we only open Inbox folders in the left pane. The problem is that the mailbox names shown there are formed from Display Name attributes. But those names are all identical! All the mailboxes are owned by John Smith, so they should be all named John Smith - so that letter recepient sees "John Smith" in the "from" field, no matter what mailbox it is sent from. Also, the user knows what's his name - no need to tell him. He wants to know what mailbox he works with. So we need a way to either: a) customize OWA to show mailbox email address instead of user Display Name, or b) make Exchange use another attribute to put in the "from" field when sending letters 4) Okay, we can switch between mailboxes using "Open Other Mailbox" in the upper-right corner menu. But: a) To select a mailbox we need to enter its name (or first letters). It there a way to show a list of links to mailboxes the user has full access to? Eg in the page header... b) If we start entering the first letters, we see a popup list with possible mailboxes to be opened. But there are all mailboxes (apparently from GAL), not only mailboxes the user has permission to open! How to filter that popup list? c) The same problem as in (3) with mailbox naming. We can see the opened mailbox email address ONLY in the page URL, which is insufficient for many users. In the left pane we see "John Smith" which is useless. 5) Each mailbox is tied with a separate user in AD. If one has several mailboxes, we need to have additional dummy AD accounts, create additional OUs to store them, etc. That's not very nice, is there any standartized, optimal way to build such a structure? We would really appreciate any answers or additional info for any of these questions. Thank you in advance.

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  • SQL Server 2005: Improving performance for thousands or Insert requests. logout-login time= 120ms.

    - by Rad
    Can somebody shed some lights on how SQL Server 2005 deals with may request issued by a client using ADO.NET 2.0. Below is the shortend output of SQL Trace. I can see that connection pooling is working (I believe there is only one connection being pooled). What is not clear to me is why we have so many sp_reset_connection calls i.e a series of: Audit Login, SQL:BatchStarting, RPC:Starting and Audit Logout for each loop in for loop below. I can see that there is constant switching between tempdb and master database which leads me to conclude that we lost the context when next connection is created by fetching it from the pool based on ConectionString argument. I can see that every 15ms I can get 100-200 login/logout per second (reported at the same time by Profiler). The after 15ms I have again a series fo 100-200 login/logout per second. I need clarification on how this might affect much complex insert queries in production environment. I use Enterprise Library 2006, the code is compiled with VS 2005 and it is a console application that parses a flat file with 10 of thousand of rows grouping parent-child rows, runs on an application server and runs 2 stored procedure on a remote SQL Server 2005 inserting a parent record, retrieves Identity value and using it calls the second stored procedure 1, 2 or multiple times (sometimes several thousands) inserting child records. The child table has close to 10 million records with 5-10 indexes some of them being covering non-clustered. There is a pretty complex Insert trigger that copies inserted detail record to an archive table. All in all I only have 7 inserts per second which means it can take 2-4 hours for 50 thousand records. When I run Profiler on the test server (that is almost equivalent with production server) I can see that there is about 120ms between Audit Logout and Audit Login trace entries which almost give me chance to insert about 8 records. So my question is if there is some way to improve inserting of records since the company loads 100 thousands of records and does daily planning and has SLA to fulfill client request coming as flat file orders and some big files 10 thousands have to be processed(imported quickly). 4 hours to import 60 thousands should be reduced to 30 minutes. I was thinking to use BatchSize of DataAdapter to send multiple stored procedure calls, SQL Bulk inserts to batch multiple inserts from DataReader or DataTable, SSIS fast load. But I don't know how to properly analyze re-indexing and stats population and maybe this has to take some time to finish. What is worse is that the company uses the biggest table for reporting and other online processing and indexes cannot be dropped. I manage transaction manually by setting a field to a value and do an transactional update changing that value to a new value that other applications are using to get committed rows. Please advise how to approach this problem. For now I am trying to have a staging tables with minimal logging in a separate database and no indexes and I will try to do batched (massive) parent child inserts. I believe Production DB has simple recovery model, but it could be full recovery. If DB user that is being used by my .NET console application has bulkadmin role does it mean its bulk inserts are minimally logged. I understand that when a table has clustered and many non-clustered indexes that inserts are still logged for each row. Connection pooling is working, but with many login/logouts. Why? for (int i = 1; i <= 10000; i++){ using (SqlConnection conn = new SqlConnection("server=(local);database=master;integrated security=sspi;")) {conn.Open(); using (SqlCommand cmd = conn.CreateCommand()){ cmd.CommandText = "use tempdb"; cmd.ExecuteNonQuery();}}} SQL Server Profiler trace: Audit Login master 2010-01-13 23:18:45.337 1 - Nonpooled SQL:BatchStarting use tempdb master 2010-01-13 23:18:45.337 RPC:Starting exec sp_reset_conn tempdb 2010-01-13 23:18:45.337 Audit Logout tempdb 2010-01-13 23:18:45.337 2 - Pooled Audit Login -- network protocol master 2010-01-13 23:18:45.383 2 - Pooled SQL:BatchStarting use tempdb master 2010-01-13 23:18:45.383 RPC:Starting exec sp_reset_conn tempdb 2010-01-13 23:18:45.383 Audit Logout tempdb 2010-01-13 23:18:45.383 2 - Pooled Audit Login -- network protocol master 2010-01-13 23:18:45.383 2 - Pooled SQL:BatchStarting use tempdb master 2010-01-13 23:18:45.383 RPC:Starting exec sp_reset_conn tempdb 2010-01-13 23:18:45.383 Audit Logout tempdb 2010-01-13 23:18:45.383 2 - Pooled

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  • PHP/MySQL Interview - How would you have answered?

    - by martincarlin87
    I was asked this interview question so thought I would post it here to see how other users would answer: Please write some code which connects to a MySQL database (any host/user/pass), retrieves the current date & time from the database, compares it to the current date & time on the local server (i.e. where the application is running), and reports on the difference. The reporting aspect should be a simple HTML page, so that in theory this script can be put on a web server, set to point to a particular database server, and it would tell us whether the two servers’ times are in sync (or close to being in sync). This is what I put: // Connect to database server $dbhost = 'localhost'; $dbuser = 'xxx'; $dbpass = 'xxx'; $dbname = 'xxx'; $conn = mysql_connect($dbhost, $dbuser, $dbpass) or die (mysql_error()); // Select database mysql_select_db($dbname) or die(mysql_error()); // Retrieve the current time from the database server $sql = 'SELECT NOW() AS db_server_time'; // Execute the query $result = mysql_query($sql) or die(mysql_error()); // Since query has now completed, get the time of the web server $php_server_time = date("Y-m-d h:m:s"); // Store query results in an array $row = mysql_fetch_array($result); // Retrieve time result from the array $db_server_time = $row['db_server_time']; echo $db_server_time . '<br />'; echo $php_server_time; if ($php_server_time != $db_server_time) { // Server times are not identical echo '<p>Database server and web server are not in sync!</p>'; // Convert the time stamps into seconds since 01/01/1970 $php_seconds = strtotime($php_server_time); $sql_seconds = strtotime($db_server_time); // Subtract smaller number from biggest number to avoid getting a negative result if ($php_seconds > $sql_seconds) { $time_difference = $php_seconds - $sql_seconds; } else { $time_difference = $sql_seconds - $php_seconds; } // convert the time difference in seconds to a formatted string displaying hours, minutes and seconds $nice_time_difference = gmdate("H:i:s", $time_difference); echo '<p>Time difference between the servers is ' . $nice_time_difference; } else { // Timestamps are exactly the same echo '<p>Database server and web server are in sync with each other!</p>'; } Yes, I know that I have used the deprecated mysql_* functions but that aside, how would you have answered, i.e. what changes would you make and why? Are there any factors I have omitted which I should take into consideration? The interesting thing is that my results always seem to be an exact number of minutes apart when executed on my hosting account: 2012-12-06 11:47:07 2012-12-06 11:12:07

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  • Understanding and Controlling Parallel Query Processing in SQL Server

    Data warehousing and general reporting applications tend to be CPU intensive because they need to read and process a large number of rows. To facilitate quick data processing for queries that touch a large amount of data, Microsoft SQL Server exploits the power of multiple logical processors to provide parallel query processing operations such as parallel scans. Through extensive testing, we have learned that, for most large queries that are executed in a parallel fashion, SQL Server can deliver linear or nearly linear response time speedup as the number of logical processors increases. However, some queries in high parallelism scenarios perform suboptimally. There are also some parallelism issues that can occur in a multi-user parallel query workload. This white paper describes parallel performance problems you might encounter when you run such queries and workloads, and it explains why these issues occur. In addition, it presents how data warehouse developers can detect these issues, and how they can work around them or mitigate them.

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  • SQL Pre-Con…at the Beach

    - by Argenis
      Building upon the success of SQL Rally 2012 (where we packed a room full of DBAs), my friend Robert Davis [Twitter|Blog] and yours truly will be again delivering our day-long Pre-Conference “Demystifying Database Administration Best Practices” this Friday (6/8/2012) – right before SQLSaturday #132 in Pensacola, FL. If you are in the vicinity of Pensacola, come join us! We had tons of fun at Rally. Robert and I love sharing tips and stories that will help you on your day to day duties as a DBA. Some of the topics that we’ll touch on (this is by no means a comprehensive list) Active Directory configuration for SQL Server Deployments Windows Server Deployments Storage and I/O High Availability / Disaster Recovery / Business Continuity Replication Day-To-Day Operations Maintenance TempDB Code Reviews Other Database and Server Settings   Follow this link to sign up for the Pre-Con at Pensacola: http://demystifyingdba.eventbrite.com/ Here’s a blog post that Robert made on the subject of Best Practices.  Hope to see you there!

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  • SQL Pre-Con…at the Beach

    - by Argenis
      Building upon the success of SQL Rally 2012 (where we packed a room full of DBAs), my friend Robert Davis [Twitter|Blog] and yours truly will be again delivering our day-long Pre-Conference “Demystifying Database Administration Best Practices” this Friday (6/8/2012) – right before SQLSaturday #132 in Pensacola, FL. If you are in the vicinity of Pensacola, come join us! We had tons of fun at Rally. Robert and I love sharing tips and stories that will help you on your day to day duties as a DBA. Some of the topics that we’ll touch on (this is by no means a comprehensive list) Active Directory configuration for SQL Server Deployments Windows Server Deployments Storage and I/O High Availability / Disaster Recovery / Business Continuity Replication Day-To-Day Operations Maintenance TempDB Code Reviews Other Database and Server Settings   Follow this link to sign up for the Pre-Con at Pensacola: http://demystifyingdba.eventbrite.com/ Here’s a blog post that Robert made on the subject of Best Practices.  Hope to see you there!

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  • LINQ for SQL Developers and DBA’s

    - by AtulThakor
    Firstly I’d just like to thank the guys who organise the SQL Server User Group (Martin/Tony/Chris) and for giving me the opportunity to speak at the recent event. Sorry about the slides taking so long but here they are along with some extra information. Firstly the demo’s were all done using LINQPad 4.0 which can be downloaded here: http://www.linqpad.net/ There are 2 versions 3.5/4.0 With 3.5 you should be able to replicate the problem I showed where a query using a parameter which is X characters long would create a different execution plan to a query which uses a parameter which is Y characters long, otherwise I would just use 4.0 The sample database used is AdventureWorksLT2008 which can be downloaded from here: http://msftdbprodsamples.codeplex.com/releases/view/37109 The scripts have been named so that you can select the appropriate way to run them i.e.: C# expression / C#statement, each script can be run individually be highlighting the query and clicking the play symbol or hitting F5. Scripts and Slides: http://sqlblogcasts.com/blogs/atulthakor/An%20Introduction%20to%20LINQ.zip Please don't hesitate in sending any questions via email/twitter, I’ll try my best to answer your questions! Thanks, Atul

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