query optimization in sql server 2012

Label:Original: SQL Server 2012:SQL Server architecture--The life cycle of a query (part 1th)To reduce the scope of the read operation, this article first looks at a simple select query

Original: SQL Server 2012:SQL Server architecture--The life cycle of a query (part 2nd)Planning cache (Plan caches)If SQL Server has found a

To reduce the scope of the read operation, this article first looks at a simple select query and then introduces additional procedures related to performing the update operation. Finally, you will read that SQL Server uses the terminology and processes associated with the Restore tool when optimizing performance.relational and storage engines,

comes from the bottom line value and is independent of your hardware speed, in each SQL Server appliance (Like-for-like version. Bo Main note: not related to the version. The cost of generating each plan is the same. Because our select query is very simple, it exits the operation during the pre-optimization period bec

Yesterday's SQL Server query performance optimization-index creation principle (I) mainly introduced the principle. today are some of the main principles and checks the created indexes. Iii. indexing principles In general, building indexes depends on the data usage scenarios. In other words, which

Original: SQL Server 2012:SQL Server architecture--The life cycle of a query (part 3rd) (end)A simple update queryYou should now know the query life cycle of reading only the data, and

--Cross join produces a Cartesian value (x*y) SELECT * from Student crosses Join dbo. ClassInfo--Another way of writing select * from Student, ClassInfo--INNER join (Inner can omit) select *from Student JOIN dbo. ClassInfo on dbo. Student.class = dbo. classinfo.id;--Inner Join SELECT *from Student Inner join dbo. ClassInfo on dbo. Student.class = dbo. Classinfo.id; --on condition, usually the primary foreign key, but not limited to the primary foreign key--on condition, which allows multiple, a

curve before optimization, the figure shows the method call TP99 indicator jitter between 100~300ms is the optimized performance curve, can see the optimized method call TP99 indicator in the 100~150ms range, and relatively stable; Although WSFC no longer has a heartbeat line like Windows cluster, in order to avoid the impact of large data synchronization on the application access link, it is recommended to increase the direct line (or dedicated d

'the value of the Key5' fromheadertable awhereA.headerid= 10000 SELECTA.*, t.a0001 as 'the value of the Key1', t.a0002 as 'the value of the Key2', t.a0003 as 'the value of the Key3', t.a0004 as 'the value of the Key4', t.a0005 as 'the value of the Key5' fromHeadertable AInner Join (SelectHeaderid, Detailkey, detailvalues fromdetailtable) T Pivot (MAX(detailvalues) forDetailkeyinch(a0001,a0002,a0003,a0004,a0005)) T onT.headerid=A.headeridwhereA.headerid= 10000 　　

Original: Set STATISTICS io and set STATISTICS time in SQL Server query performance optimizationIn recent times, has been exploring the SQL Server query performance issues, of course, also aimless search for a lot of information,

The word booksearch may be unfamiliar to many developers. Many people have encountered this word, but they have not paid enough attention to it, so they have always ignored its existence. The word booksearch may be unfamiliar to many developers. Many people have encountered this word, but they have not paid enough attention to it, so they have always ignored its existence. The growth of SQL Server Cognit

The growth of SQL Server Cognition 1. I don't have to graduate or work for a long time. I only know the relationship between SQL and SQL Server Oracle and MySql. I usually think that SQL is S