sql server query tuning advisor

can speed up our grouping. Below is an example of the Orders table for Northwind: --an index on the EmployeeID of the Orders table. Select Employeeid,count (*)From OrdersGROUP BY EmployeeID --View the execution plan, which leverages the index on the EmployeeID. If you change to the following query: Select Employeeid,sum (Freight)From OrdersGROUP BY EmployeeID --View the execution plan, which does not use the index on the EmployeeID. Instead, the full

ELSEStatement_end_offsetEND -Statement_start_offset)/ 2) fromSys.dm_exec_sql_text (sql_handle)) asQuery_text--, Plan_handle,db_name(qp.dbid), Qp.query_plan fromsys.dm_exec_query_stats Crossapply Sys.dm_exec_query_plan (plan_handle) QPORDER by(total_logical_reads+Total_logical_writes)/Execution_countDESC--indexes that have not been usedSELECTO.nameobject_name --Table name, I.name index_name--Index name, I.type_desc--whether the clustered index, S.user

partial database backup and file backup. The new restore statement allows you to use full or partial database backup and record file backup for restoration. These replace the dump and load statements in earlier versions of SQL Server. For a complete list of new statements and options for SQL Server 7.0 and

Recently, the following project encountered an urgent problem, my old horse and young people to fight together. The problem is that many queries are incredibly slow when the pressure data is poured into the database. Said there must be some basic guidelines for performance issues. The order of performance problems tunning 1 Architecture design (software architecture and database design, poor design is almost fatal) 2 Code defects (90% of performance problems) 3 Add index (this is to be deter

, one is not perfect function also dare to take Out (2000) The second functional architecture of the outstanding design makes the function has a strong continuity and Scalability (2005 2000 of the function to retain and improve). The optimization tool is simple to use 1: Use SQL Server Porfiler (Event Viewer) to record all the steps of the operation database in the business system and save it as a working

calculation.In fact, the goal of bitmap computing is very simple: pre-filtering , because our statement requires the result item to compare more than 10000 rows of data, in the thread behind us to take the parallel scan of the way to obtain the data. Due to the large amount of data, the various threads in the process of the completion of data acquisition time is different, in order to avoid the slow execution of a thread, resulting in overall congestion, the index introduced a bitmap operation

an execution plan, and stored in a database of SQL statements, is a collection of control flow language, the speed of course fast. 48, the return value of the function is not too large, this overhead is very large. A user-defined function that executes as a cursor consumes a large amount of resources if a large result is returned with a stored procedure. 49, as far as possible to avoid repeated access to the same or several tables, especially the lar

Label:SELECT Mig.index_group_handle, Mid.index_handle, CONVERT (Decimal (28,1), Migs.avg_total_user_cost * Migs.avg_user_impact * (Migs.user_seeks + Migs.user_scans) ) as Improvement_measure, ' CREATE index idx_ ' + object_name (object_id,database_id) + ' _missing_ ' + Replace (replace (replace (ISNULL (Mid.equality_columns, ') + ' _ ' + ISNULL (Mid.inequality_columns, '), ', ', ' _ '), ', '), ' [', ' '), '] ', ') + ' On [' + object_name (object_id,database_id) + '] (' + ISNULL (mid.equality_col

SQL Server database self-optimizing release time under large data volume:2013-12-17 15:19:00 Source: Forum anonymous Keywords: database development1.1: Add secondary data filesStarting with SQL SERVER 2005, the database does not generate the NDF data file by default, generally there is a master data file (MDF) is enou

In our OLAP implementation, SQL is extremely complex and uses a lot of temporary tables. During the installation of tempdb, the local disk path for SQL Server installation is selected by default, and no disk array is used. When learning PostgreSQL, we found that many experts suggest placing the temporary tablespace on SSD or using RAID0 + 1 to increase the write

released, the data page will not be in the memory of the data cache, This causes the memory problem to be the bottleneck of the disk. PAGEIOLATCH_EX is write data, this is generally the disk write speed obviously keep up, and memory is not directly related. Here is the resource wait time for query pageiolatch_x: Select Wait_type, waiting_tasks_count, Wait_time_ms, Max_wait_time_ms, Signal_wait_time_ms from sys.dm_os_wait_stats wherelike' pageiolat

Label:Original address: Http://social.technet.microsoft.com/wiki/contents/articles/4995.sql-server-columnstore-performance-tuning.aspxSQL Server's Columnstore index is a new version of SQL Server release that improves query performance for the Data Warehouse, and this articl

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 and then introduces additional procedures re

) Select DATEADD (Wk,datediff (Wk,0,getdate ()), 0) query yesterday Date: Select CONVERT (Char,dateadd (dd,-1,getdate)), 111 //111 is the style number, (100-114) query the first day of the month Date: Select DATEADD (mm, DATEDIFF (Mm,0,getdate ()), 0) as FirstDay query last day of the month Date: Select DATEADD (M S,-3,dateadd (mm, DATEDIFF (M,0,getdate ()) +1, 0

-- Script used to obtain the connection information of the SQL Server server (based on the original shard creation and writing) Declare@ Dbname sysname,-- The name of the database to be queried (empty for all). The connection information of all databases is queried by default.@ Brief deip bit-- Whether to display the IP address (0 NO, 1 Yes). This control is add