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  • Ubuntu lucid, maverick high iowait

    - by netom
    I'm using Ubuntu, and I've got the same problem with Lucid and Maverick. From time to time, especially a few minutes after boot, the iowait goes between 50-100% and the box is unusable. Everything that tries to access the disk freezes. I have the following setup: Hard disk: Model Family: Western Digital Caviar Green family Device Model: WDC WD15EADS-00P8B0 Serial Number: WD-WMAVU0391287 Firmware Version: 01.00A01 User Capacity: 1.500.301.910.016 bytes I have a quad core Intel Core2 Q6600 processor, and 4G of memory. When the high iowait occurs, usually 4 processes are active: kdmflush (two procs) jbd2/dm-0-8 jbd2/db-1-8 and a few more starving user processes of course. I know this from top and iotop. Any suggestions about why this is happening? There are a lot of q/a-s about linux and high iowait, but none of them helped so far, I even tweaked the hard disk not to park the head in every 8 seconds (Load cycle count is 50334!!!!! :o ), but nothing. Problem persists. Thank you in advance.

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  • High disk I/O - jbd2/sda2-8 process

    - by Evan Hamlet
    I have run a file server on a CentOS 5.8 final server. My only concern at the moment is what appears to be intermittent but continuous high disk I/O activity causing a general slowdown because of jbd2/sda2-8 process. jbd2/sda2-8 is making use of /dev/sda2, which is the 2nd partition of the first harddrive (IE: root partition). More info: using "iotop" the culprit appears to be "jbd2/sda1-8" making writes every second, which appears to be a kernel process associated with journaling on the ext4 filesystem, if my googling around is correct. I see "jbd2/sda2-8" appearing here every now and then, but certainly not every 3 seconds.. when idle, it appears about 1 or 2 times per minute. When I'm using the system, it appears more frequently. ATOP results: http://grabilla.com/02b14-8022db2e-4eb9-4f10-8e10-d65c49ad7530.png IOTOP results: http://grabilla.com/02b14-cf74b25d-4063-4447-9210-7d1b9b70e25b.png HTOP results: grabilla. com/02b14-ad8cad0e-89b0-46d3-849d-4fd515c1e690.png jbd2/sda2-8 is the processes I see with iotop making writes on disk even though it's not in use at all. Does someone has any idea how could I solve the high disk usage caused jbd2/sda2-8 process?

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  • Weirdly high ping on direct ethernet connection?

    - by Antriel
    I bought new Lenovo IdeaCentre H430 pc and I'm having problem with high pings. Windows 7 with on-board realtek NIC. Fresh install, fully updated, drivers installed from included CD. When I start pinging router (direct 1Gb ethernet connection, 1 hop), pings start at <1ms (which is fine) and after a while they jump to 300-1000ms. I loaded up live ubuntu to test if the problem might be in HW. It's not, in ubuntu pings were always <1ms. I also noticed that when I start using connection somehow, pings go down to 1ms, but go back up when I stop using it (tested by accessing live camera feed on LAN). Power Options set to max performance. I disabled Interrupt Moderation on the NIC, didn't help. I tested it in the safe mode with networking, same problem there. It slows down our client-server based programs and I have no idea what's causing it. All I could google up was that disabling Interrupt Moderation would help, it didn't though. Anyone had similar problems? tl;nr: Computer is giving high pings to router when idle and normal pings when network is under load, it slows down our software significantly.

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  • CPU temperatures high on new build after gaming

    - by Reznor
    My friend had a problem with his computer a while back. His games were crashing, even within the menus. He was stumped as to what the problem was, so I posted on here requesting help. He found out the day later, when his computer would start up but wouldn't display anything on the screen. His video card must have came screwed up. So, he got a replacement. Now, there's a new problem. His temperatures, which were acceptable before, are now insanely high. His GPU temperature runs 70-80c, which is understandable considering he's running his games maxed out, but the real problem here is his processor and motherboard temperatures. All four of his cores are running at 88-90c after coming out of a game. His motherboard temperature was also 70c at one point. In terms of cooling, his case should definitely be adequate. He has an Antec Twelve Hundred. He's using stock fans. The cable management in his case is very good; better than average. He's using the stock heatsink with the processor too, but note, it was fine before the replacement, so it isn't like there's some inherent problem. He has checked the case too. Everything's fine! No cables in the way. The heatsink is seated properly. He turned his case fans up to high, as well, but the temperatures are persisting. Could the processor be overheating due to running games maxed out? Any ideas?

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  • Developing high-performance and scalable zend framework website [on hold]

    - by Daniel
    We are going to develop an ads website like http://www.gumtree.com/ (it will not be like this one but just to give you an ideea) and we are having some issues regarding performance and scalability. We are planning on using Zend Framework for this project but this is all that I'm sure off at this point. I don't think a classic approch like Zend Framework (PHP) + MySQL + Memcache + jQuery (and I would throw Doctrine 2 in there to) will fix result in a high-performance application. I was thinking on making this a RESTful application (with Zend Framework) + NGINX (or maybe MongoDB) + Memcache (or eAccelerator -- I understand this will create problems with scalability on multiple servers) + jQuery or maybe throw Backbone.js in there, a CDN for static content, a server for images and a scalable server for the requests and the rest. My questions are: - What do you think about my approch? - What solutions would you recommand for developing an high performance, scalable application expected to have a lot of traffic using PHP(Zend Framework 2)...I would be interested in your approch. I should note that I'm a Zend developer, I'm working with Zend for over 3 years, this is why I'm choosing it.

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  • High availability virtual machines

    - by Jeremy
    I've been reading a lot about high availability virtualization, either via Hyper-V or VMWare. In that context, essentially high availabliity means that the VM is hosted by a closter of physical servers (nodes), so if one of the physical servers goes down, the VM can still be served by other physical servers. So far so good, the physical cluster and the VM itself are highly available. However if the service being provided, let's say SQL server, MSDTC, or any other service, are actually being provided by the VM image and the virtualized operating system. So I imagine that there is still a point of failure at the virtual layer that isn't accounted for. Something could happen within the virtual machine itself that the physican cluster can not account for, correct? In that instance the physican failover cluster (Hyper-V) or VMWare host, can not fail over, because the issue is not with one of the servers in the physical cluster - failing over a physical node would not do any good. Does this necessitate building a virtual failover cluster on top of the physical one, or is this not necessary? Alternatively, I suppose you could skip the phsyical clustering, and just cluster at the virtual layer (Child based failover clustering), because that should still survive a physical failure. See image below showing parent based (left), child based (right) and a combination (center). Is parent based as far as you need to go, or is child based more appropriate?

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  • What cause high CPU usage on the server during file upload

    - by bosiang
    When I try to upload a huge file size (approx 2GB), the server cpu usage goes really high. What should I do to fix this? I just use standard html form and php, for file upload. I'm sorry if I post on the wrong forum. Please point me to the right direction here is the result of "top" command during uploading 4 files (18mb, 38mb, 60mb, 33mb) 1904 apache 20 0 33504 5740 1952 R 28.3 0.2 0:02.19 httpd 1905 apache 20 0 33504 5740 1952 R 28.3 0.2 0:01.99 httpd 1903 apache 20 0 33232 6968 3060 R 28.0 0.2 0:01.98 httpd 1910 apache 20 0 33240 6020 2248 S 11.5 0.2 0:02.85 httpd 2133 root 20 0 2656 1124 896 R 1.6 0.0 0:00.71 top 1 root 20 0 2864 1404 1188 S 0.0 0.0 0:03.99 init the code for chunking, although eventhough I don't use this code (just simple file upload), it still cause that high cpu usage function sendRequest() { //clean the screen //bars.innerHTML = ''; var file = document.getElementById('fileToUpload'); for(var i = 0; i < file.files.length; i++) { var blob = file.files[i]; var originalFileName = blob.name; var filePart = 0 const BYTES_PER_CHUNK = 100 * 1024 * 1024; // 10MB chunk sizes. var realFileSize = blob.size; var start = 0; var end = BYTES_PER_CHUNK; totalChunks = Math.ceil(realFileSize / BYTES_PER_CHUNK); alert(realFileSize); while( start < realFileSize ) { if (blob.webkitSlice) { //for Google Chrome var chunk = blob.webkitSlice(start, end); } else if (blob.mozSlice) { //for Mozilla Firefox var chunk = blob.mozSlice(start, end); } uploadFile(chunk, originalFileName, filePart, totalChunks, i); filePart++; start = end; end = start + BYTES_PER_CHUNK; } } }

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  • SQL SERVER – 2011 – Wait Type – Day 25 of 28

    - by pinaldave
    Since the beginning of the series, I have been getting the following question again and again: “What are the changes in SQL Server 2011 – Denali with respect to Wait Types?” SQL Server 2011 – Denali is yet to be released, and making statements on the subject will be inappropriate. Denali CTP1 has been released so I suggest that all of you download the same and experiment on it. I quickly compared the wait stats of SQL Server 2008 R2 and Denali (CTP1) and found the following changes: Wait Types Exists in SQL Server 2008 R2 and Not Exists in SQL Server 2011 “Denali” SOS_RESERVEDMEMBLOCKLIST SOS_LOCALALLOCATORLIST QUERY_WAIT_ERRHDL_SERVICE QUERY_ERRHDL_SERVICE_DONE XE_PACKAGE_LOCK_BACKOFF Wait Types Exists in SQL Server 2011 and Not Exists in SQL Server 2008 SLEEP_MASTERMDREADY SOS_MEMORY_TOPLEVELBLOCKALLOCATOR SOS_PHYS_PAGE_CACHE FILESTREAM_WORKITEM_QUEUE FILESTREAM_FILE_OBJECT FILESTREAM_FCB FILESTREAM_CACHE XE_CALLBACK_LIST PWAIT_MD_RELATION_CACHE PWAIT_MD_SERVER_CACHE PWAIT_MD_LOGIN_STATS DISPATCHER_PRIORITY_QUEUE_SEMAPHORE FT_PROPERTYLIST_CACHE SECURITY_KEYRING_RWLOCK BROKER_TRANSMISSION_WORK BROKER_TRANSMISSION_OBJECT BROKER_TRANSMISSION_TABLE BROKER_DISPATCHER BROKER_FORWARDER UCS_MANAGER UCS_TRANSPORT UCS_MEMORY_NOTIFICATION UCS_ENDPOINT_CHANGE UCS_TRANSPORT_STREAM_CHANGE QUERY_TASK_ENQUEUE_MUTEX DBCC_SCALE_OUT_EXPR_CACHE PWAIT_ALL_COMPONENTS_INITIALIZED PREEMPTIVE_SP_SERVER_DIAGNOSTICS SP_SERVER_DIAGNOSTICS_SLEEP SP_SERVER_DIAGNOSTICS_INIT_MUTEX AM_INDBUILD_ALLOCATION QRY_PARALLEL_THREAD_MUTEX FT_MASTER_MERGE_COORDINATOR PWAIT_RESOURCE_SEMAPHORE_FT_PARALLEL_QUERY_SYNC REDO_THREAD_PENDING_WORK REDO_THREAD_SYNC COUNTRECOVERYMGR HADR_DB_COMMAND HADR_TRANSPORT_SESSION HADR_CLUSAPI_CALL PWAIT_HADR_CHANGE_NOTIFIER_TERMINATION_SYNC PWAIT_HADR_ACTION_COMPLETED PWAIT_HADR_OFFLINE_COMPLETED PWAIT_HADR_ONLINE_COMPLETED PWAIT_HADR_FORCEFAILOVER_COMPLETED PWAIT_HADR_WORKITEM_COMPLETED HADR_WORK_POOL HADR_WORK_QUEUE HADR_LOGCAPTURE_SYNC LOGPOOL_CACHESIZE LOGPOOL_FREEPOOLS LOGPOOL_REPLACEMENTSET LOGPOOL_CONSUMERSET LOGPOOL_MGRSET LOGPOOL_CONSUMER LOGPOOLREFCOUNTEDOBJECT_REFDONE HADR_SYNC_COMMIT HADR_AG_MUTEX PWAIT_SECURITY_CACHE_INVALIDATION PWAIT_HADR_SERVER_READY_CONNECTIONS HADR_FILESTREAM_MANAGER HADR_FILESTREAM_BLOCK_FLUSH HADR_FILESTREAM_IOMGR XDES_HISTORY XDES_SNAPSHOT HADR_FILESTREAM_IOMGR_IOCOMPLETION UCS_SESSION_REGISTRATION ENABLE_EMPTY_VERSIONING HADR_DB_OP_START_SYNC HADR_DB_OP_COMPLETION_SYNC HADR_LOGPROGRESS_SYNC HADR_TRANSPORT_DBRLIST HADR_FAILOVER_PARTNER XDESTSVERMGR GHOSTCLEANUPSYNCMGR HADR_AR_UNLOAD_COMPLETED HADR_PARTNER_SYNC HADR_DBSTATECHANGE_SYNC We already know that Wait Types and Wait Stats are going to be the next big thing in the next version of SQL Server. So now I am eagerly waiting to dig deeper in the wait stats. Read all the post in the Wait Types and Queue series. Note: The information presented here is from my experience and there is no way that I claim it to be accurate. I suggest reading Book OnLine for further clarification. All the discussion of Wait Stats in this blog is generic and varies from system to system. It is recommended that you test this on a development server before implementing it to a production server. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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  • SQL SERVER – Generate Report for Index Physical Statistics – SSMS

    - by pinaldave
    Few days ago, I wrote about SQL SERVER – Out of the Box – Activity and Performance Reports from SSSMS (Link). A user asked me a question regarding if we can use similar reports to get the detail about Indexes. Yes, it is possible to do the same. There are similar type of reports are available at Database level, just like those available at the Server Instance level. You can right click on Database name and click Reports. Under Standard Reports, you will find following reports. Disk Usage Disk Usage by Top Tables Disk Usage by Table Disk Usage by Partition Backup and Restore Events All Transactions All Blocking Transactions Top Transactions by Age Top Transactions by Blocked Transactions Count Top Transactions by Locks Count Resource Locking Statistics by Objects Object Execute Statistics Database Consistency history Index Usage Statistics Index Physical Statistics Schema Change history User Statistics Select the Reports with name Index Physical Statistics. Once click, a report containing all the index names along with other information related to index will be visible, e.g. Index Type and number of partitions. One column that caught my interest was Operation Recommended. In some place, it suggested that index needs to be rebuilt. It is also possible to click and expand the column of partitions and see additional details about index as well. DBA and Developers who just want to have idea about how your index is and its physical statistics can use this tool. Click to Enlarge Note: Please note that I will rebuild my indexes just because this report is recommending it. There are many other parameters you need to consider before rebuilding indexes. However, this tool gives you the accurate stats of your index and it can be right away exported to Excel or PDF writing by clicking on the report. Reference : Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Index, SQL Optimization, SQL Performance, SQL Query, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, SQL Utility, T SQL, Technology

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  • SQL SERVER – Four Posts on Removing the Bookmark Lookup – Key Lookup

    - by pinaldave
    In recent times I have observed that not many people have proper understanding of what is bookmark lookup or key lookup. Increasing numbers of the questions tells me that this is something developers are encountering every single day but have no idea how to deal with it. I have previously written three articles on this subject. I want to point all of you looking for further information on the same post. SQL SERVER – Query Optimization – Remove Bookmark Lookup – Remove RID Lookup – Remove Key Lookup SQL SERVER – Query Optimization – Remove Bookmark Lookup – Remove RID Lookup – Remove Key Lookup – Part 2 SQL SERVER – Query Optimization – Remove Bookmark Lookup – Remove RID Lookup – Remove Key Lookup – Part 3 SQL SERVER – Interesting Observation – Execution Plan and Results of Aggregate Concatenation Queries In one of my recent class we had in depth conversation about what are the alternative of creating covering indexes to remove the bookmark lookup. I really want to this question open to all of you and see what community thinks about the same. Is there any other way then creating covering index or included index to remove his expensive keylookup? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Backup and Restore, SQL Index, SQL Optimization, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQLAuthority News, SQLServer, T SQL, Technology

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  • SQLAuthority News – Feature Pack for Microsoft SQL Server 2005 SP4

    - by pinaldave
    If you are still using SQL Server 2005 – I suggest that you consider migrating to later version of the SQL Server 2008/2008 R2. Due to any reason, you wanted to continue using SQL Server 2005, I suggest that you take a look at the Feature Pack for Microsoft SQL Server 2005 SP4. There are many different tools and features available in pack, which can be very handy and can solve issues. Microsoft ADOMD.NET Microsoft Core XML Services (MSXML) 6.0 Microsoft OLEDB Provider for DB2 Microsoft SQL Server Management Pack for MOM 2005 Microsoft SQL Server 2000 PivotTable Services Microsoft SQL Server 2000 DTS Designer Components Microsoft SQL Server Native Client Microsoft SQL Server 2005 Analysis Services 9.0 OLE DB Provider Microsoft SQL Server 2005 Backward Compatibility Components Microsoft SQL Server 2005 Command Line Query Utility Microsoft SQL Server 2005 Datamining Viewer Controls Microsoft SQL Server 2005 JDBC Driver Microsoft SQL Server 2005 Management Objects Collection Microsoft SQL Server 2005 Compact Edition Microsoft SQL Server 2005 Notification Services Client Components Microsoft SQL Server 2005 Upgrade Advisor Microsoft .NET Data Provider for mySAP Business Suite, Preview Version Reporting Add-In for Microsoft Visual Web Developer 2005 Express Microsoft Exception Message Box Data Mining Managed Plug-in Algorithm API for SQL Server 2005 Microsoft SQL Server 2005 Reporting Services Add-in for Microsoft SharePoint Technologies Microsoft SQL Server 2005 Data Mining Add-ins for Microsoft Office 2007 SQL Server 2005 Performance Dashboard Reports SQL Server 2005 Best Practices Analyzer Download Feature Pack for Microsoft SQL Server 2005 SP4 Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: SQL, SQL Authority, SQL Documentation, SQL Download, SQL Query, SQL Server, SQL Service Pack, SQL Tips and Tricks, SQLAuthority News, T SQL, Technology

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  • SQL SERVER – Subquery or Join – Various Options – SQL Server Engine knows the Best

    - by pinaldave
    This is followup post of my earlier article SQL SERVER – Convert IN to EXISTS – Performance Talk, after reading all the comments I have received I felt that I could write more on the same subject to clear few things out. First let us run following four queries, all of them are giving exactly same resultset. USE AdventureWorks GO -- use of = SELECT * FROM HumanResources.Employee E WHERE E.EmployeeID = ( SELECT EA.EmployeeID FROM HumanResources.EmployeeAddress EA WHERE EA.EmployeeID = E.EmployeeID) GO -- use of in SELECT * FROM HumanResources.Employee E WHERE E.EmployeeID IN ( SELECT EA.EmployeeID FROM HumanResources.EmployeeAddress EA WHERE EA.EmployeeID = E.EmployeeID) GO -- use of exists SELECT * FROM HumanResources.Employee E WHERE EXISTS ( SELECT EA.EmployeeID FROM HumanResources.EmployeeAddress EA WHERE EA.EmployeeID = E.EmployeeID) GO -- Use of Join SELECT * FROM HumanResources.Employee E INNER JOIN HumanResources.EmployeeAddress EA ON E.EmployeeID = EA.EmployeeID GO Let us compare the execution plan of the queries listed above. Click on image to see larger image. It is quite clear from the execution plan that in case of IN, EXISTS and JOIN SQL Server Engines is smart enough to figure out what is the best optimal plan of Merge Join for the same query and execute the same. However, in the case of use of Equal (=) Operator, SQL Server is forced to use Nested Loop and test each result of the inner query and compare to outer query, leading to cut the performance. Please note that here I no mean suggesting that Nested Loop is bad or Merge Join is better. This can very well vary on your machine and amount of resources available on your computer. When I see Equal (=) operator used in query like above, I usually recommend to see if user can use IN or EXISTS or JOIN. As I said, this can very much vary on different system. What is your take in above query? I believe SQL Server Engines is usually pretty smart to figure out what is ideal execution plan and use it. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Joins, SQL Optimization, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQL SERVER – Concat Strings in SQL Server using T-SQL – SQL in Sixty Seconds #035 – Video

    - by pinaldave
    Concatenating  string is one of the most common tasks in SQL Server and every developer has to come across it. We have to concat the string when we have to see the display full name of the person by first name and last name. In this video we will see various methods to concatenate the strings. SQL Server 2012 has introduced new function CONCAT which concatenates the strings much efficiently. When we concat values with ‘+’ in SQL Server we have to make sure that values are in string format. However, when we attempt to concat integer we have to convert the integers to a string or else it will throw an error. However, with the newly introduce the function of CONCAT in SQL Server 2012 we do not have to worry about this kind of issue. It concatenates strings and integers without casting or converting them. You can specify various values as a parameter to CONCAT functions and it concatenates them together. Let us see how to concat the values in Sixty Seconds: Here is the script which is used in the video. -- Method 1: Concatenating two strings SELECT 'FirstName' + ' ' + 'LastName' AS FullName -- Method 2: Concatenating two Numbers SELECT CAST(1 AS VARCHAR(10)) + ' ' + CAST(2 AS VARCHAR(10)) -- Method 3: Concatenating values of table columns SELECT FirstName + ' ' + LastName AS FullName FROM AdventureWorks2012.Person.Person -- Method 4: SQL Server 2012 CONCAT function SELECT CONCAT('FirstName' , ' ' , 'LastName') AS FullName -- Method 5: SQL Server 2012 CONCAT function SELECT CONCAT('FirstName' , ' ' , 1) AS FullName Related Tips in SQL in Sixty Seconds: SQL SERVER – Concat Function in SQL Server – SQL Concatenation String Function – CONCAT() – A Quick Introduction 2012 Functions – FORMAT() and CONCAT() – An Interesting Usage A Quick Trick about SQL Server 2012 CONCAT Function – PRINT A Quick Trick about SQL Server 2012 CONCAT function What would you like to see in the next SQL in Sixty Seconds video? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Database, Pinal Dave, PostADay, SQL, SQL Authority, SQL in Sixty Seconds, SQL Query, SQL Scripts, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, T SQL, Technology, Video Tagged: Excel

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  • SQL SERVER – Subquery or Join – Various Options – SQL Server Engine Knows the Best – Part 2

    - by pinaldave
    This blog post is part 2 of the earlier written article SQL SERVER – Subquery or Join – Various Options – SQL Server Engine knows the Best by Paulo R. Pereira. Paulo has left excellent comment to earlier article once again proving the point that SQL Server Engine is smart enough to figure out the best plan itself and uses the same for the query. Let us go over his comment as he has posted. “I think IN or EXISTS is the best choice, because there is a little difference between ‘Merge Join’ of query with JOIN (Inner Join) and the others options (Left Semi Join), and JOIN can give more results than IN or EXISTS if the relationship is 1:0..N and not 1:0..1. And if I try use NOT IN and NOT EXISTS the query plan is different from LEFT JOIN too (Left Anti Semi Join vs. Left Outer Join + Filter). So, I found a case where EXISTS has a different query plan than IN or ANY/SOME:” USE AdventureWorks GO -- use of SOME SELECT * FROM HumanResources.Employee E WHERE E.EmployeeID = SOME ( SELECT EA.EmployeeID FROM HumanResources.EmployeeAddress EA UNION ALL SELECT EA.EmployeeID FROM HumanResources.EmployeeDepartmentHistory EA ) -- use of IN SELECT * FROM HumanResources.Employee E WHERE E.EmployeeID IN ( SELECT EA.EmployeeID FROM HumanResources.EmployeeAddress EA UNION ALL SELECT EA.EmployeeID FROM HumanResources.EmployeeDepartmentHistory EA ) -- use of EXISTS SELECT * FROM HumanResources.Employee E WHERE EXISTS ( SELECT EA.EmployeeID FROM HumanResources.EmployeeAddress EA UNION ALL SELECT EA.EmployeeID FROM HumanResources.EmployeeDepartmentHistory EA ) When looked into execution plan of the queries listed above indeed we do get different plans for queries and SQL Server Engines creates the best (least cost) plan for each query. Click on image to see larger images. Thanks Paulo for your wonderful contribution. Reference : Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, Readers Contribution, SQL, SQL Authority, SQL Joins, SQL Optimization, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQLAuthority News – A Successful Performance Tuning Seminar at Pune – Dec 4-5, 2010

    - by pinaldave
    This is report to my third of very successful seminar event on SQL Server Performance Tuning. SQL Server Performance Tuning Seminar in Colombo was oversubscribed with total of 35 attendees. You can read the details over here SQLAuthority News – SQL Server Performance Optimizations Seminar – Grand Success – Colombo, Sri Lanka – Oct 4 – 5, 2010. SQL Server Performance Tuning Seminar in Hyderabad was oversubscribed with total of 25 attendees. You can read the details over here SQL SERVER – A Successful Performance Tuning Seminar – Hyderabad – Nov 27-28, 2010. The same Seminar was offered in Pune on December 4,-5, 2010. We had another successful seminar with lots of performance talk. This seminar was attended by 30 attendees. The best part of the seminar was that along with the our agenda, we have talked about following very interesting concepts. Deadlocks Detection and Removal Dynamic SQL and Inline Code SQL Optimizations Multiple OR conditions and performance tuning Dynamic Search Condition Building and Improvement Memory Cache and Improvement Bottleneck Detections – Memory, CPU and IO Beginning Performance Tuning on Production Parametrization Improving already Super Fast Queries Convenience vs. Performance Proper way to create Indexes Hints and Disadvantages I had great time doing the seminar and sharing my performance tricks with all. The highlight of this seminar was I have explained the attendees, how I begin doing performance tuning when I go for Performance Tuning Consultations.   Pinal Dave at SQL Performance Tuning Seminar SQL Server Performance Tuning Seminar Pinal Dave at SQL Performance Tuning Seminar Pinal Dave at SQL Performance Tuning Seminar SQL Server Performance Tuning Seminar SQL Server Performance Tuning Seminar This seminar series are 100% demo oriented and no usual PowerPoint talk. They are created from my experiences of various organizations for performance tuning. I am not planning any more seminar this year as it was great but I am booked currently for next 60 days at various performance tuning engagements. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Optimization, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, SQL Training, SQLAuthority News, T SQL, Technology

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  • SQL SERVER – Standard Reports from SQL Server Management Studio – SQL in Sixty Seconds #016 – Video

    - by pinaldave
    SQL Server management Studio 2012 is wonderful tool and has many different features. Many times, an average user does not use them as they are not aware about these features. Today, we will learn one such feature. SSMS comes with many inbuilt performance and activity reports, but we do not use it to the full potential. Connect to SQL Server Node >> Right Click on it >> Go to Reports >> Click on Standard Reports >> Pick Any Report. Please note that some of the reports can be IO intensive and not suggested to run during business hours! More on Standard Reports: SQL SERVER – Out of the Box – Activity and Performance Reports from SSSMS SQL SERVER – Generate Report for Index Physical Statistics – SSMS SQL SERVER – Configure Management Data Collection in Quick Steps I encourage you to submit your ideas for SQL in Sixty Seconds. We will try to accommodate as many as we can. If we like your idea we promise to share with you educational material. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Database, Pinal Dave, PostADay, SQL, SQL Authority, SQL in Sixty Seconds, SQL Query, SQL Scripts, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, T SQL, Technology, Video

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  • SQL SERVER – Activity Monitor and Performance Issue

    - by pinaldave
    We had wonderful SQLAuthority News – Community Tech Days – December 11, 2010 event yesterday. After the event, we had meeting among Jacob Sebastian, Vinod Kumar, Rushabh Mehta and myself. We all were sharing our experience about performance tuning consultations. During the conversation, Jacob has shared wonderful story of his recent observation. The story is very small but the moral of the story is very important. The story is about a client, who had continuously performance issues. Client used Activity Monitor (Read More: SQL SERVER – 2008 – Location of Activity Monitor – Where is SQL Serve Activity Monitor Located) to check the performance issues. The pattern of the performance issues was very much common all the time. Every time, after a while the computer stopped responding. After doing in-depth performance analysis, Jacob realized that client once opened activity monitor never closed it. The same activity monitor itself is very expensive process. The tool, which helped to debug the performance issues, also helped (negatively) to bring down the server. After closing the activity monitor which was open for long time, the server did not have performance issues. Moral of the story: Activity Monitor is great tool but use it with care and close it when not needed. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Best Practices, Pinal Dave, SQL, SQL Authority, SQL Optimization, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQL SERVER – Concat Function in SQL Server – SQL Concatenation

    - by pinaldave
    Earlier this week, I was delivering Advanced BI training on the subject of “SQL Server 2008 R2″. I had great time delivering the session. During the session, we talked about SQL Server 2010 Denali. Suddenly one of the attendees suggested his displeasure for the product. He said, even though, SQL Server is now in moving very fast and have proved many times a good enterprise solution, it does not have some basic functions. I naturally asked him for example and he suggested CONCAT() which exists in MySQL and Oracle. The answer is very simple – the equalent function in SQL Server to CONCAT() is ‘+’ (plus operator without quotes). Method 1: Concatenating two strings SELECT 'FirstName' + ' ' + 'LastName' AS FullName Method 2: Concatenating two Numbers SELECT CAST(1 AS VARCHAR(10)) + 'R' + CAST(2 AS VARCHAR(10)) Method 3: Concatenating values from table columns SELECT FirstName + ' ' + LastName FROM AdventureWorks.Person.Contact Well, this may look very simple but sometime it is very difficult to find the information for simple things only. Do you have any such example which you would like to share with community? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL String, SQL Tips and Tricks, T SQL, Technology

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  • SQLAuthority News – Three Posts on Reporting – T-SQL Tuesday #005

    - by pinaldave
    If you are following my blog, you already know that I am more of “T-SQL and Performance Tuning” type of person. I do have a good understanding of Business Intelligence suit and I also do certain training sessions on the same subject. When I was writing the blog post for T-SQL Tuesday #005 – Reporting, I realized that I have written a post that clearly explains how to generate reports using SQL Server Management Studio. Here is a quick recap on how one can use SSMS and out-of-the-box reports which can help many developers. Please note that they can be resource-intensive as well, so please use SSMS carefully. SQL SERVER – Generate Report for Index Physical Statistics – SSMS SQL SERVER – Out of the Box – Activity and Performance Reports from SSSMS SQL SERVER – Configure Management Data Collection in Quick Steps – T-SQL Tuesday #005 Junior developers and DBA can use these reports right away and can also start learning and exploring most database performance issues with the help of Sr. DBAs. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Performance, SQL Query, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, T SQL, Technology Tagged: SQL Reporting, SQL Reports

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  • SQLAuthority News – Pinal Dave: Blogger, MVP and now Interviewee by Michael J Swart

    - by pinaldave
    Michael J. Swart is a very unique person. I have often exchanged emails with him and also used a couple of his scripts in my presentations (with his permission). Every time I conduct spatial database presentation, I always start with his script where he has drawn the wonderful image of Botticelli’s Birth of Venus. I often think he is more of a creative artist than IT professional. However, if you read his blog posts and articles, they are top notch and each article is as creative as his caricatures. He is wonderful, inspiring, creative and most importantly, very humble. He recently took my interview and asked me some very interesting question. To answer his question, I had to share some of the interesting aspects of my life which I have had never shared in any interview before. He made me share the following interesting facts. Pinal Dave Caricatures Read my Interview Here are a few questions that I have answered at his blog: How I met my wife? Best moments of my life? How to pronounce my last name? Who inspired me? English as a Third Language. I am also thankful to Michael for drawing my caricature. I really liked it and I am very glad that he took time to do so. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: About Me, Pinal Dave, PostADay, Readers Question, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQL SERVER – Installing AdventureWorks for SQL Server 2011

    - by pinaldave
    I just began with SQL Server 2011 Denali CTP1. The very first thing, I realized that there is no AdventureWorks Sample Database available for Denali. I quickly searched online and reached to Microsoft documentations where it provides information of the how to install (restore) AdventureWorks for SQL Server 2011 for Denali. Download the AdventureWorks from here. Run following script (replace your path of mdf file. CREATE DATABASE AdventureWorks2008R2 ON (FILENAME = 'C:\SQL 11 CTP1\CTP1\AdventureWorks2008R2_Data.mdf') FOR ATTACH_REBUILD_LOG ; When you run above script it will give you following message and you are DONE! File activation failure. The physical file name "C:\Program Files\Microsoft SQL Server\MSSQL11.MSSQLSERVER\MSSQL\DATA\AdventureWorks2008R2_Log.ldf" may be incorrect. New log file 'C:\SQL 11 CTP1\CTP1\AdventureWorks2008R2_log.ldf' was created. Converting database 'AdventureWorks2008R2' from version 679 to the current version 684. Database 'AdventureWorks2008R2' running the upgrade step from version 679 to version 680. Database 'AdventureWorks2008R2' running the upgrade step from version 680 to version 681. Database 'AdventureWorks2008R2' running the upgrade step from version 681 to version 682. Database 'AdventureWorks2008R2' running the upgrade step from version 682 to version 683. Database 'AdventureWorks2008R2' running the upgrade step from version 683 to version 684. I will soon write my experience about Denali. However, SQL Server Management Studio more started to look a like Visual Studio. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Backup and Restore, SQL Query, SQL Scripts, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, T SQL, Technology

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  • SQLAuthority News – Statistics Used by the Query Optimizer in Microsoft SQL Server 2008 – Microsoft Whitepaper

    - by pinaldave
    I recently presented session on Statistics and Best Practices in Virtual Tech Days on Nov 22, 2010. The sessions was very popular and I got many questions right after the sessions. The number question I had received was where everybody can get the further information. I am very much happy that my sessions created some curiosity for one of the most important feature of the SQL Server. Statistics are the heart of the SQL Server. Microsoft has published a white paper on the subject how statistics are useful to Query Optimizer. Here is the abstract of the same white paper from Microsoft. Statistics Used by the Query Optimizer in Microsoft SQL Server 2008 Writer: Eric N. Hanson and Yavor Angelov Microsoft SQL Server 2008 collects statistical information about indexes and column data stored in the database. These statistics are used by the SQL Server query optimizer to choose the most efficient plan for retrieving or updating data. This paper describes what data is collected, where it is stored, and which commands create, update, and delete statistics. By default, SQL Server 2008 also creates and updates statistics automatically, when such an operation is considered to be useful. This paper also outlines how these defaults can be changed on different levels (column, table, and database). In addition, it presents how certain query language features, such as Transact-SQL variables, interact with use of statistics by the optimizer, and it provides guidance for using these features when writing queries so you can obtain good query performance. Link to white paper Statistics Used by the Query Optimizer in Microsoft SQL Server 2008 ?Reference: Pinal Dave (http://blog.SQLAuthority.com)   Filed under: Pinal Dave, SQL, SQL Authority, SQL Documentation, SQL Download, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL White Papers, SQLAuthority News, T SQL, Technology

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  • SQLAuthority News – Spot the SQLAuthority Baby Contest – SQL Server Cheat Sheet

    - by pinaldave
    Last Year during the TechEd India 2009 SQL Server Cheat Sheets were instant hit. Yesterday when I announce that I am going to attend TechED India 2010 at Bangalore, I received many requests for the same. I have only 30 copies available at this moment.  I will print more copies of the same after this event. For the moment I am going to run quick content to win SQL Server Cheat Sheet during this event. The contest is very simple. My 7 months old daughter will join me in this trip. She will be staying with me in the same hotel where the event is organized. Here is the detail for contest: Contest: If you Spot SQLAuthority Baby, get one SQL Server Cheat Sheet. Rules: Every hour the first person to spot SQLAuthority Baby will get 1 SQL Server Cheat Sheet. If you spot her and the hourly SQL Server Cheat Sheet is given away, you still have chance to get a copy. Drop your business card or email address and we will contact you for your copy. SQLAuthority Baby is very easy to spot. Shaivi Dave If you are not attending this event and want copy, you can easily download the same from link below. Download SQL Server Cheat Sheet from here. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: MVP, Pinal Dave, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority News, T SQL, Technology Tagged: SQL Cheat Sheet, TechEd, TechEdIn

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  • SQL SERVER – Find Max Worker Count using DMV – 32 Bit and 64 Bit

    - by pinaldave
    During several recent training courses, I found it very interesting that Worker Thread is not quite known to everyone despite the fact that it is a very important feature. At some point in the discussion, one of the attendees mentioned that we can double the Worker Thread if we double the CPU (add the same number of CPU that we have on current system). The same discussion has triggered this quick article. Here is the DMV which can be used to find out Max Worker Count SELECT max_workers_count FROM sys.dm_os_sys_info Let us run the above query on my system and find the results. As my system is 32 bit and I have two CPU, the Max Worker Count is displayed as 512. To address the previous discussion, adding more CPU does not necessarily double the Worker Count. In fact, the logic behind this simple principle is as follows: For x86 (32-bit) upto 4 logical processors  max worker threads = 256 For x86 (32-bit) more than 4 logical processors  max worker threads = 256 + ((# Procs – 4) * 8) For x64 (64-bit) upto 4 logical processors  max worker threads = 512 For x64 (64-bit) more than 4 logical processors  max worker threads = 512+ ((# Procs – 4) * 8) In addition to this, you can configure the Max Worker Thread by using SSMS. Go to Server Node >> Right Click and Select Property >> Select Process and modify setting under Worker Threads. According to Book On Line, the default Worker Thread settings are appropriate for most of the systems. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL System Table, SQL Tips and Tricks, T SQL, Technology Tagged: SQL DMV

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  • SQL SERVER – Color Coding SQL Server Management Studio Status Bar – SQL in Sixty Seconds #023 – Video

    - by pinaldave
    I often see developers executing the unplanned code on production server when they actually want to execute on the development server. Developers and DBAs get confused because when they use SQL Server Management Studio (SSMS) they forget to pay attention to the server they are connecting. It is very easy to fix this problem. You can select different color for a different server. Once you have different color for different server in the status bar, it will be easier for developer easily notice the server against which they are about to execute the script. Personally when I work on SQL Server development, here is the color code, which I follow. I keep Green for my development server, blue for my staging server and red for my production server. Honestly color coding does not signify much but different color for different server is the key here. More Tips on SSMS in SQL in Sixty Seconds: Generate Script for Schema and Data in SQL Server – SQL in Sixty Seconds #021  Remove Debug Button in SQL Server Management Studio – SQL in Sixty Seconds #020  Three Tricks to Comment T-SQL in SQL Server Management Studio – SQL in Sixty Seconds #019  Importing CSV into SQL Server – SQL in Sixty Seconds #018   Tricks to Replace SELECT * with Column Names – SQL in Sixty Seconds #017 I encourage you to submit your ideas for SQL in Sixty Seconds. We will try to accommodate as many as we can. If we like your idea we promise to share with you educational material. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Database, Pinal Dave, PostADay, SQL, SQL Authority, SQL in Sixty Seconds, SQL Query, SQL Scripts, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, T SQL, Technology, Video

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