-- sys.dm_db_index_physical_stats(Transact-SQL)
-- http://technet.microsoft.com/ko-kr/library/ms188917.aspx
-- 1.지정한 테이블에 대한 정보 반환
DECLARE @db_id SMALLINT;
DECLARE @object_id INT;
SET @db_id = DB_ID(N'testDB');
SET @object_id = OBJECT_ID(N'testDB.dbo.t3');
IF @db_id IS NULL
BEGIN;
PRINT N'Invalid database';
END;
ELSE IF @object_id IS NULL
BEGIN;
PRINT N'Invalid object';
END;
ELSE
BEGIN;
SELECT * FROM sys.dm_db_index_physical_stats(@db_id, @object_id, NULL, NULL , 'LIMITED');
END;
GO
-- 2.모든 데이터베이스에 대한 정보 반환
SELECT * FROM sys.dm_db_index_physical_stats (NULL, NULL, NULL, NULL, NULL);
GO
-- 3.스크립트에 sys.dm_db_index_physical_stats를 사용하여 인덱스를 다시 작성하거나 다시 구성
-- 다음 예에서는 데이터베이스에서 평균 조각화가 10%를 넘는 모든 파티션을 자동으로 다시 구성하거나 다시 작성합니다. 이 쿼리를 실행하려면 VIEW DATABASE STATE 권한이 필요합니다
-- Ensure a USE <databasename> statement has been executed first.
SET NOCOUNT ON;
DECLARE @objectid int;
DECLARE @indexid int;
DECLARE @partitioncount bigint;
DECLARE @schemaname nvarchar(130);
DECLARE @objectname nvarchar(130);
DECLARE @indexname nvarchar(130);
DECLARE @partitionnum bigint;
DECLARE @partitions bigint;
DECLARE @frag float;
DECLARE @command nvarchar(4000);
-- Conditionally select tables and indexes from the sys.dm_db_index_physical_stats function
-- and convert object and index IDs to names.
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 (DB_ID(), 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.
WHILE (1=1)
BEGIN;
FETCH NEXT
FROM partitions
INTO @objectid, @indexid, @partitionnum, @frag;
IF @@FETCH_STATUS < 0 BREAK;
SELECT @objectname = QUOTENAME(o.name), @schemaname = QUOTENAME(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 = QUOTENAME(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
SET @command = N'ALTER INDEX ' + @indexname + N' ON ' + @schemaname + N'.' + @objectname + N' REORGANIZE';
IF @frag >= 30.0
SET @command = N'ALTER INDEX ' + @indexname + N' ON ' + @schemaname + N'.' + @objectname + N' REBUILD';
IF @partitioncount > 1
SET @command = @command + N' PARTITION=' + CAST(@partitionnum AS nvarchar(10));
EXEC (@command);
PRINT N'Executed: ' + @command;
END;
-- Close and deallocate the cursor.
CLOSE partitions;
DEALLOCATE partitions;
-- Drop the temporary table.
DROP TABLE #work_to_do;
GO
-- 4. sys.dm_db_index_physical_stats를 사용하여 페이지 대 압축된 페이지 수 표시
SELECT o.name,
ips.partition_number,
ips.index_type_desc,
ips.record_count, ips.avg_record_size_in_bytes,
ips.min_record_size_in_bytes,
ips.max_record_size_in_bytes,
ips.page_count, ips.compressed_page_count
FROM sys.dm_db_index_physical_stats ( DB_ID(), NULL, NULL, NULL, 'DETAILED') ips
JOIN sys.objects o on o.object_id = ips.object_id
ORDER BY record_count DESC;
-- 5.SAMPLED 모드에서 sys.dm_db_index_physical_stats 사용
-- 다음 예에서는 SAMPLED 모드가 DETAILED 모드 결과와 다른 대략적인 값을 어떻게 반환하는지를 보여 줍니다.
CREATE TABLE t3 (col1 int PRIMARY KEY, col2 varchar(500)) WITH(DATA_COMPRESSION = PAGE);
GO
BEGIN TRAN
DECLARE @idx int = 0;
WHILE @idx < 1000000
BEGIN
INSERT INTO t3 (col1, col2)
VALUES (@idx,
REPLICATE ('a', 100) + CAST (@idx as varchar(10)) + REPLICATE ('a', 380))
SET @idx = @idx + 1
END
COMMIT;
GO
SELECT page_count, compressed_page_count, forwarded_record_count, *
FROM sys.dm_db_index_physical_stats (db_id(),
object_id ('t3'), null, null, 'SAMPLED');
SELECT page_count, compressed_page_count, forwarded_record_count, *
FROM sys.dm_db_index_physical_stats (db_id(),
object_id ('t3'), null, null, 'DETAILED');
