How to use Database Compatibility to increase your migration success

Understanding SQL Server database compatibility levels helps in understanding risk in upgrades Read more →

SELECT 1 FROM TABLE

Question: I'm working on an Enterprise application upgrade and have hit some problems. As part of the debugging process I'm inspecting the sql queries executing. The program is currently running SELECT 1 FROM TABLE. (replace TABLE with actual table name). What is the purpose of SELECT 1 FROM TABLE ? Answer: The SELECT 1 FROM TABLE technique is often used in certain products. The first question is what does this sql statement actually do? When you execute SELECT 1 FROM TABLE , there will be a Scan , because the purpose of SELECT 1 FROM TABLE is to return a... Read more →

Type Conversion may affect cardinality estimate in query plan

Type Conversion may affect cardinality estimate in query plan is a warning found on Execution Plans. This may negatively impact the correct index usage. Cardinality is a critical part of how indexes are used. Data type matching has many benefits. It’s a practise often neglected in database design but which can have a number of long term consequences for query access and database performance One long term cost of neglecting data type matching is it can lead to more memory required. When data types are matched , this leads to less bytes requires , leading to less data pages in... Read more →

Automatic Index Tuning by default on Azure sql server

Automated Index Tuning by default on Azure will start on January 15th 2018. It’s clear from reading the announcement – it is a very well tested technology based on large amounts of field testing, and will continue to improve with time. This announcement inevitably will raise questions about the future of the DBA and the The future of the DBA profession (SQL Server DBA) , but like most automation it will open up other opportunities for DBAs to add value to the database management process. Automation,auto install, patching , template builds. Bring it on! The less of these tasks you're... Read more →

SQL Server 100 cpu diagnose

Question: Users are reporting long delays in query responses. I checked on the server and noticed CPU counter at 100 % on Performance Monitor. There are 4 cores associated to this server and all the cores were hovering around 100%. How can I diagnose the underlying cause ? Answer: It’s a common problem faced by DBAs , where the server is sitting at 100% for prolonged periods. Check there are no other processes outside of SQL Server which are causing the server to be at 100%. Typically security scans, virus scans and monitoring can be root causes. I have also... Read more →