在一个大型数据库中,数据的更改是非常频繁的。 而建立在这些数据上的索引也是需要经常去维护的。 否则这这些数据索引就起不到起应起的作用。甚至会成为数据库本身的负担。 我们就要定期的对数据库的索引进行维护 我在MSDN上发现了这个脚本不过其中有些小问题我已经修正 大家可以使用这个脚本对数据库的索引进行日常维护 复制代码 代码如下: SET NOCOUNT ON; DECLARE @objectid int; DECLARE @indexid int; DECLARE @partitioncount bigint; DECLARE @schemaname sysname; DECLARE @objectname sysname; DECLARE @indexname sysname; DECLARE @partitionnum bigint; DECLARE @partitions bigint; DECLARE @frag float; DECLARE @command varchar(8000); DECLARE @dbId int; -- ensure the temporary table does not exist IF EXISTS (SELECT name FROM sys.objects WHERE name = "work_to_do") DROP TABLE work_to_do; -- conditionally select from the function, converting object and index IDs to names. set @dbId=DB_ID(); SELECT object_id AS objectid, index_id AS indexid, partition_number AS partitionnum, avg_fragmentation_in_percent AS frag INTO work_to_do FROM sys.dm_db_index_physical_stats (@dbId, NULL, NULL , NULL, "LIMITED") WHERE avg_fragmentation_in_percent > 10.0 AND index_id > 0; -- Declare the cursor for the list of partitions to be processed. DECLARE partitions CURSOR FOR SELECT * FROM work_to_do;
-- Open the cursor. OPEN partitions;
-- Loop through the partitions. FETCH NEXT FROM partitions INTO @objectid, @indexid, @partitionnum, @frag;
WHILE @@FETCH_STATUS = 0 BEGIN; SELECT @objectname = o.name, @schemaname = s.name FROM sys.objects AS o JOIN sys.schemas as s ON s.schema_id = o.schema_id WHERE o.object_id = @objectid;
SELECT @indexname = name FROM sys.indexes WHERE object_id = @objectid AND index_id = @indexid;
SELECT @partitioncount = count (*) FROM sys.partitions WHERE object_id = @objectid AND index_id = @indexid;
-- 30 is an arbitrary decision point at which to switch between reorganizing and rebuilding IF @frag < 30.0 BEGIN; SELECT @command = "ALTER INDEX [" + @indexname + "] ON " + @schemaname + ".[" + @objectname + "] REORGANIZE"; IF @partitioncount > 1 SELECT @command = @command + " PARTITION=" + CONVERT (CHAR, @partitionnum);
EXEC (@command); END;
IF @frag >= 30.0 BEGIN; SELECT @command = "ALTER INDEX [" + @indexname +"] ON " + @schemaname + ".[" + @objectname + "] REBUILD"; IF @partitioncount > 1 SELECT @command = @command + " PARTITION=" + CONVERT (CHAR, @partitionnum);
FETCH NEXT FROM partitions INTO @objectid, @indexid, @partitionnum, @frag; END; -- Close and deallocate the cursor. CLOSE partitions; DEALLOCATE partitions;
-- drop the temporary table IF EXISTS (SELECT name FROM sys.objects WHERE name = "work_to_do") DROP TABLE work_to_do; GO