Create view_CompressionGainsRevised.sql

Evaluate-Compression-Gains/view_CompressionGainsRevised.sql

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+-- https://learn.microsoft.com/en-us/previous-versions/sql/sql-server-2008/dd894051(v=sql.100)?redirectedfrom=MSDN
+SET NOCOUNT ON;
+
+DECLARE
+	@uptime varchar(12)
+  , @startdate datetime
+  , @sqlmajorver int
+  , @sqlcmd nvarchar(500)
+  , @params nvarchar(500);
+SELECT @sqlmajorver = CONVERT (int, (@@microsoftversion / 0x1000000) & 0xff);
+
+IF @sqlmajorver = 9
+	BEGIN
+		SET @sqlcmd
+			= N'SELECT 
+				  @StartDateOUT = login_time
+				, @UpTimeOUT = DATEDIFF(mi, login_time, GETDATE()) 
+				FROM 
+				  master..sysprocesses WHERE spid = 1';
+	END;
+ELSE
+	BEGIN
+		SET @sqlcmd
+			= N'SELECT 
+				  @StartDateOUT = sqlserver_start_time
+				, @UpTimeOUT = DATEDIFF(mi,sqlserver_start_time,GETDATE()) 
+				FROM 
+				  sys.dm_os_sys_info';
+	END;
+
+SET @params = N'@StartDateOUT DATETIME OUTPUT, @UpTimeOUT VARCHAR(12) OUTPUT';
+
+EXECUTE sp_executesql
+	@sqlcmd
+  , @params
+  , @startdateout = @startdate OUTPUT
+  , @uptimeout = @uptime OUTPUT;
+
+SELECT
+	@startdate AS sq_server_start_date_time
+  , CONVERT (varchar(4), @uptime / 60 / 24) + 'd '
+	+ CONVERT (varchar(4), @uptime / 60 % 24) + 'h '
+	+ CONVERT (varchar(4), @uptime % 60) + 'm' AS uptime;
+
+DROP TABLE IF EXISTS ##compression;
+CREATE TABLE ##compression
+(
+	schema_id int NOT NULL
+  , schema_name sysname NOT NULL
+  , object_id int NOT NULL
+  , object_name sysname NOT NULL
+  , partition int NOT NULL
+  , index_id int NOT NULL
+  , index_name sysname NULL
+  , index_type varchar(50) NOT NULL
+  , rows bigint NOT NULL
+  , current_compression_type nvarchar(60) NOT NULL
+  , percent_scan decimal(5, 2) NOT NULL
+  , percent_update decimal(5, 2) NOT NULL
+  , size_with_current_compression_in_kb bigint NULL
+  , size_with_row_compression_in_kb bigint NULL
+  , savings_by_row_compression_in_percent decimal(5, 2) NULL
+  , size_with_page_compression_in_kb bigint NULL
+  , savings_by_page_compression_in_percent decimal(5, 2) NULL
+  , recommended_compression_type varchar(50) NULL
+  , recommended_compression_command nvarchar(4000) NULL
+);
+
+DROP TABLE IF EXISTS ##estimated_row_compression;
+CREATE TABLE ##estimated_row_compression
+(
+	object_name sysname NOT NULL
+  , schema_name sysname NOT NULL
+  , index_id int NOT NULL
+  , partition int NOT NULL
+  , size_with_current_compression_setting_in_kb bigint NOT NULL
+  , size_with_requested_compression_setting_in_kb bigint NOT NULL
+  , sample_size_with_current_compression_setting_in_kb bigint NOT NULL
+  , sample_size_with_requested_compression_setting_in_kb bigint NOT NULL
+);
+
+DROP TABLE IF EXISTS ##estimated_page_compression;
+CREATE TABLE ##estimated_page_compression
+(
+	object_name sysname NOT NULL
+  , schema_name sysname NOT NULL
+  , index_id int NOT NULL
+  , partition int NOT NULL
+  , size_with_current_compression_setting_in_kb bigint NOT NULL
+  , size_with_requested_compression_setting_in_kb bigint NOT NULL
+  , sample_size_with_current_compression_setting_in_kb bigint NOT NULL
+  , sample_size_with_requested_compression_setting_in_kb bigint NOT NULL
+);
+
+INSERT ##compression
+	(
+		schema_id
+	  , schema_name
+	  , object_id
+	  , object_name
+	  , partition
+	  , index_id
+	  , index_name
+	  , index_type
+	  , rows
+	  , current_compression_type
+	  , percent_scan
+	  , percent_update
+	  , size_with_current_compression_in_kb
+	  , size_with_row_compression_in_kb
+	  , savings_by_row_compression_in_percent
+	  , size_with_page_compression_in_kb
+	  , savings_by_page_compression_in_percent
+	  , recommended_compression_type
+	  , recommended_compression_command
+	)
+SELECT
+	sch.schema_id AS schema_id
+  , sch.name AS schema_name
+  , obj.object_id
+  , obj.name AS object_name
+  , par.partition_number AS partition
+  , ind.index_id
+  , ind.name AS index_name
+  , ind.type_desc AS index_type
+  , par.rows
+  , data_compression_desc AS current_compression_type
+  , ISNULL (
+			   stat.range_scan_count * 100.0
+			   / NULLIF (
+							(stat.range_scan_count + stat.leaf_insert_count
+							 + stat.leaf_delete_count + stat.leaf_update_count
+							 + stat.leaf_page_merge_count
+							 + stat.singleton_lookup_count
+							), 0
+						), 0
+		   ) AS percent_scan
+  , ISNULL (
+			   stat.leaf_update_count * 100.0
+			   / NULLIF (
+							(stat.range_scan_count + stat.leaf_insert_count
+							 + stat.leaf_delete_count + stat.leaf_update_count
+							 + stat.leaf_page_merge_count
+							 + stat.singleton_lookup_count
+							), 0
+						), 0
+		   ) AS percent_update
+  , NULL AS size_with_current_compression_in_kb
+  , NULL AS size_with_row_compression_in_kb
+  , NULL AS savings_by_row_compression_in_percent
+  , NULL AS size_with_page_compression_in_kb
+  , NULL AS savings_by_page_compression_in_percent
+  , NULL AS recommended_compression_type
+  , NULL AS recommended_compression_command
+FROM
+	sys.objects AS obj
+INNER JOIN
+	sys.schemas AS sch
+ON
+	obj.schema_id = sch.schema_id
+INNER JOIN
+	sys.indexes AS ind
+ON
+	obj.object_id = ind.object_id
+INNER JOIN
+	sys.partitions AS par
+ON
+	ind.object_id = par.object_id
+	AND ind.index_id = par.index_id
+OUTER APPLY sys.dm_db_index_operational_stats (
+												  DB_ID (), ind.object_id
+												, ind.index_id
+												, par.partition_number
+											  ) AS stat
+WHERE
+	OBJECTPROPERTY (obj.object_id, 'IsUserTable') = 1
+ORDER BY
+	sch.name, obj.name;
+
+DECLARE @number_of_objects int;
+SELECT @number_of_objects = COUNT (*)
+FROM
+	##compression;
+
+DECLARE
+	@schema_name sysname
+  , @object_name sysname
+  , @partition int
+  , @index_id int
+  , @index_name sysname
+  , @counter int = 1;
+
+DECLARE cur CURSOR FAST_FORWARD FOR
+SELECT
+	schema_name, object_name, partition, index_id, index_name
+FROM
+	##compression;
+OPEN cur;
+FETCH NEXT FROM cur
+INTO
+	@schema_name, @object_name, @partition, @index_id, @index_name;
+WHILE @@FETCH_STATUS = 0
+	BEGIN
+		RAISERROR (
+					  '%i out of %i : Estimate compression savings for %s.%s.%s partition %i'
+					, 10, 1, @counter, @number_of_objects, @schema_name
+					, @object_name, @index_name, @partition
+				  ) WITH NOWAIT;
+
+		INSERT INTO ##estimated_row_compression
+		EXEC ('sp_estimate_data_compression_savings ''' + @schema_name + ''', ''' + @object_name + ''', ''' + @index_id + ''', ''' + @partition + ''', ''ROW''');
+		INSERT INTO ##estimated_page_compression
+		EXEC ('sp_estimate_data_compression_savings ''' + @schema_name + ''', ''' + @object_name + ''', ''' + @index_id + ''', ''' + @partition + ''', ''PAGE''');
+		FETCH NEXT FROM cur
+		INTO
+			@schema_name, @object_name, @partition, @index_id, @index_name;
+		SELECT @counter = @counter + 1;
+	END;
+CLOSE cur;
+DEALLOCATE cur;
+
+WITH
+	cte_compression_savings AS
+		(
+			SELECT
+				tr.object_name
+			  , tr.schema_name
+			  , tr.index_id
+			  , tr.partition
+			  , tr.size_with_current_compression_setting_in_kb
+			  , tr.size_with_requested_compression_setting_in_kb AS size_with_row_compression_in_kb
+			  , CASE
+					WHEN tr.size_with_requested_compression_setting_in_kb = 0
+						 THEN 0
+					ELSE 100
+						 - ((tr.size_with_requested_compression_setting_in_kb
+							 * 100.0
+							)
+							/ CASE
+								  WHEN tr.size_with_current_compression_setting_in_kb = 0
+									   THEN 1
+								  ELSE tr.size_with_current_compression_setting_in_kb
+							  END
+						   )
+				END AS savings_by_row_compression_in_percent
+			  , tp.size_with_requested_compression_setting_in_kb AS size_with_page_compression_in_kb
+			  , CASE
+					WHEN tr.size_with_requested_compression_setting_in_kb = 0
+						 THEN 0
+					ELSE 100
+						 - ((tp.size_with_requested_compression_setting_in_kb
+							 * 100.0
+							)
+							/ CASE
+								  WHEN tp.size_with_current_compression_setting_in_kb = 0
+									   THEN 1
+								  ELSE tp.size_with_current_compression_setting_in_kb
+							  END
+						   )
+				END AS savings_by_page_compression_in_percent
+			FROM
+				##estimated_row_compression AS tr
+			INNER JOIN
+				##estimated_page_compression AS tp
+			ON
+				tr.object_name = tp.object_name
+				AND tr.schema_name = tp.schema_name
+				AND tr.index_id = tp.index_id
+				AND tr.partition = tp.partition
+		)
+UPDATE
+	##compression
+SET
+	size_with_current_compression_in_kb = comp_sav.size_with_current_compression_setting_in_kb
+  , size_with_row_compression_in_kb = comp_sav.size_with_row_compression_in_kb
+  , savings_by_row_compression_in_percent = comp_sav.savings_by_row_compression_in_percent
+  , size_with_page_compression_in_kb = comp_sav.size_with_page_compression_in_kb
+  , savings_by_page_compression_in_percent = comp_sav.savings_by_page_compression_in_percent
+FROM
+	cte_compression_savings AS comp_sav
+INNER JOIN
+	##compression AS comp
+ON
+	comp_sav.object_name = comp.object_name
+	AND comp_sav.schema_name = comp.schema_name
+	AND comp_sav.index_id = comp.index_id
+	AND comp_sav.partition = comp.partition;
+
+
+WITH
+	cte_compression_recommendation AS
+		(
+			SELECT
+				object_id
+			  , index_id
+			  , partition
+			  , CONVERT (
+							varchar(50)
+						  , CASE
+								WHEN savings_by_row_compression_in_percent <= 0
+									 AND savings_by_page_compression_in_percent <= 0
+									 THEN 'none'
+								WHEN percent_update >= 10
+									 THEN 'row'
+								WHEN percent_scan <= 1
+									 AND percent_update <= 1
+									 AND savings_by_row_compression_in_percent > savings_by_page_compression_in_percent
+									 THEN 'row'
+								WHEN percent_scan <= 1
+									 AND percent_update <= 1
+									 AND savings_by_row_compression_in_percent < savings_by_page_compression_in_percent
+									 THEN 'page'
+								WHEN percent_scan >= 60
+									 AND percent_update <= 5
+									 THEN 'page'
+								WHEN percent_scan <= 35
+									 AND percent_update <= 5
+									 THEN 'likely row'
+								ELSE 'row'
+							END
+						) AS recommended_compression_type
+			FROM
+				##compression
+			WHERE
+				percent_scan > 0
+				OR percent_update > 0
+		)
+UPDATE
+	##compression
+SET
+	recommended_compression_type = ISNULL (
+											  com_rec.recommended_compression_type
+											, 'no recommendation'
+										  )
+  , recommended_compression_command = CASE
+										  WHEN com_rec.recommended_compression_type IN (
+																						   'row'
+																						 , 'page'
+																						 , 'likely row'
+																					   )
+											   AND com_rec.recommended_compression_type <> comp.current_compression_type
+											   THEN CASE
+														WHEN comp.index_id IN (
+																				  0
+																				, 1
+																			  )
+															 THEN CONCAT (
+																			 'ALTER TABLE '
+																		   , QUOTENAME (comp.schema_name)
+																		   , '.'
+																		   , QUOTENAME (comp.object_name)
+																		   , ' REBUILD PARTITION = '
+																		   , comp.partition
+																		   , ' WITH (DATA_COMPRESSION = '
+																		   , UPPER (com_rec.recommended_compression_type)
+																		   , ');'
+																		 )
+														ELSE CONCAT (
+																		'ALTER INDEX '
+																	  , QUOTENAME (comp.index_name)
+																	  , ' ON '
+																	  , QUOTENAME (comp.schema_name)
+																	  , '.'
+																	  , QUOTENAME (comp.object_name)
+																	  , ' REBUILD PARTITION = '
+																	  , comp.partition
+																	  , ' WITH (DATA_COMPRESSION = '
+																	  , UPPER (com_rec.recommended_compression_type)
+																	  , ');'
+																	)
+													END
+									  END
+FROM
+	##compression AS comp
+LEFT JOIN
+	cte_compression_recommendation AS com_rec
+ON
+	com_rec.object_id = comp.object_id
+	AND com_rec.index_id = comp.index_id
+	AND com_rec.partition = comp.partition;
+
+SELECT * FROM ##compression;
+
+DROP TABLE IF EXISTS ##compression;
+DROP TABLE IF EXISTS ##estimated_row_compression;
+DROP TABLE IF EXISTS ##estimated_page_compression;
+GO