dm_db_index_physical_stats (NULL, NULL, NULL, NULL, NULL); GO. ALTER INDEX ALL ON [table_name] REORGANIZE; However, if you want to rebuild all the indexes on the table, you can run the following. 11. A nonclustered columnstore index. Ignore: Fragmentation levels of 10 percent or less should not pose a performance problem, so you don’t need to do anything. NAME 'Index name', ips. To create a new maintenance plan, right click on Maintenance Plan and select New Maintenance Plan and the following window will open. For example, the heaviest index (clustered index and also pk) is running reorg for around 4 hours 30 min even do the index was. In this one case, it happens to make the query. Index maintenance in my opinion is not one of them. Execute SQL Server Agent Job. Rename. REORGANIZE, UPDATE STATISTICS and a simple SELECT statement. From sys. The problem is that the size is getting out of control, I can see up to 99% fragmentation in the Primary Key clustered indexes. DBCC DBREINDEX - use to re-index with older versions (SQL Server 2000 and earlier) sys. If you search for index rebuilding, you will find many complex scripts on the web, but this can also be done. 3. The. you are reading your query result incorrect. Recall the paper example from above: a rebuild would be like reprinting the document in the correct order and trashing the old ones. Since we are facing huge performance problem we have scheduled this Rebuild index task. If there are frequent changes to the full-text catalog, use this. As you've seen, shrinking your database causes high levels of index. . The script will do a reorg if fragmentation goes over 5 %. In the previous SQL Server versions, using the Rebuild Index and Reorganize Index Maintenance Plans tasks to fix the database indexes fragmentation issue is not highly recommended. It's better to do reorg on Nightly basis and Rebuild during the weekends. You can use Ola's Index maintenance solution or Michelle Ufford's - Index Defrag Script. . To rebuild use: ALTER INDEX __NAME_OF_INDEX__ ON __NAME_OF_TABLE__ REBUILD. Well, I’d wager some of it is backwards compatibility. I don't remember if IDENTITY INSERT ON will help. Just kidding – although the evidence does point to that. So I ran reorganize indexes and that took care of the fragmentation problem. If you want to rebuild an index the syntax is below: ALTER INDEX. Expand the Management folder. Answers. Basically, an index rebuild copies the index to another place. New. This blog entry I came across a while back will explain it much better than I can. Below the last two rows that displays the fail: Source: Reorganize Index Executing query "ALTER INDEX [PK_xxTableName] O. Reorganize Index. indexes. No right from SQL Server 7. Speaking for SQL Server, I tend to choose a index size and index fragmentation level at which point I begin performing index maintenance. If your indexes are fragmented : If index has less than 1000 pages - do not perform any index maintenance operation. Test all three and see which is fastest and which gives the least index fragmentation. Reorganizing only works on the leaf pages. Use the ReorganizeIndex Task dialog to move index pages into a more efficient search order. Create a execute sql task and schedule it through sql agent . 3) SQL Server locks acquired with SQL Server online index rebuilds. We can also run the task by running the corresponding job in SQL Server Agent. This is great if you want to release some space quickly. Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance. In this article. I want to reorganize or rebuild indexes. Just go to the table, further expand the indexing folder and right after that you can right-click on it and select the option to rebuild all the indexes. Index should be reorganized when index fragmentation is between 10% to 40%. Particularly if you are in full recovery. The MSDN page says this about reorganizing and rebuilding indexes: The SQL Server Database Engine automatically maintains indexes whenever insert, update, or delete operations are made to the underlying data. Similarly, removing. dm_exec_requests showed the REORG was only 55%. The default value for this parameter will be ‘CATALOG’. On the SQL Server Maintenance Plan Wizard page, select Next. I have maintenance job on SQL Server 2012 Enterprise Edition that runs daily to check index fragmentation and reorganize or rebuild the index based on the percentage of fragmentation. The below query rebuild or Reorganize only the necessary Indexes instead of all index rebuild, As a general recommendation the index need to rebuild that's get fragment percentage more. PARTITION Only rebuild/reorganize one partition of the index. Executing this query requires the VIEW SERVER STATE permission. Product REORGANIZE GO. You can read more on rebuilding indexes here . Once you select that option it will bring up the following screen. Depending on how many rows actually fit on the page, your mileage may vary. ALTER FULLTEXT INDEX ON [tblname] START FULL POPULATION. Let’s have a look at the differences between rebuild and reorganize indexes. Do not use REORGANIZE. My predecessor created a Maintenance Plan with 4 tasks: CHECKDB; SHRINKDATABASE (N'DB1',10,TRUNCATEONLY); it seems to be running a REORGANIZE on all Indexes for all Tables and Views and "Compact Large Objects" is checked; and then it UPDATE. Reorg the Indexes if the Fragmentation level is > 5% and <30%. Recall the paper example from above: a rebuild would be like reprinting the document in the correct order and trashing the old ones. Hi all, I have SQL Server 2017 Edition and see harmful fragmentation for all tables in DB. As well as maintenance plans, SQL Server Agent jobs are also a handy way to automate and schedule index defragmentation jobs in SQL Server. The first steps of configuring the Reorganize Index task is quite similar to the Rebuild Index task. Is this possible to do? Creating a SQL Server Maintenance Plan. As data is added to the table, the free space fills because the fill factor isn't maintained. Link To find index fragmentation at partition level . Therefore, you do not need to update statistics after performing ALTER INDEX REBUILD, DBCC DBREINDEX, DBCC INDEXDEFRAG, or ALTER INDEX REORGANIZE operations. You also can create a linked server to SQLAZURE and create a sql agent job. The first rebuilds a single index on a table and the second rebuilds all the indexes on the table. You can also see if a reorganize will help until you can do a full rebuild. This means loading the table and building all nonclustered indexes before moving on to the next one. Reorganize: The Reorganize operation is an online operation, and moves the closed row groups into the Columnstore. Create jobs to automate maintenance – create a SQL Server Agent job that will automate SQL index maintenance. We need to drag and drop tasks from the Toolbox (to open the toolbox use Ctrl + Alt + X) into the gray workspace area on the bottom as shown in the below screenshot. I am getting confused with choosing Index Reorganize/Rebuilding of indexes based on avg_fragmentation_in_percent returned by sys. When reorganizing an index, SQL Server acquires an Intent-Exclusive lock on the index B-tree. Dokumentasi SQL Server menggunakan istilah pohon B umumnya dalam referensi ke indeks. The answer is: it depends. 1. The performance benefit may not be noticeable for indexes that are used primarily for seek operations. ALTER INDEX TableDetails_UK0 ON TableDetails REBUILD WITH ( PAD_INDEX=OFF, SORT_IN_TEMPDB=ON. During index optimization, nothing accesses the server other than Red Gate SQL Monitor. I used this approach to improve performance and it worked perfectly for a long time. This REBUILD option is available in SQL Server 2008 onwards. You can always update statistics on their own. On large tables, that may be a while and not frequent enough. Stack Overflow. When you rebuild, SQL creates a new fresh index. name AS IndexName, indexstats. This means there is only 140-ish byte free per page. The import process should be reworked to bulk-load one table at a time. it will reorganise it. Because of this, and also the fact that in such a small index that fragmentation is typically negligable, you really should only be rebuilding indexes with a certain page threshold. To create SQL database maintenance plan, launch SQL Server Management Studio > expand the database instance > Management > right-click on the maintenance plan > New Maintenance Plan. The size of one of the PK Clustered indexes is greater than 200GB, and for this one a REBUILD. (About 1 TB of data including myIndex (non. A SQL Server DBA myth a day: (29/30) fixing heap fragmentation. Here's another script to add to the list. As a good start, read these: Rebuild or Reorganize: SQL Server Index Maintenance (Kendra Little)“Reorganize” index option. Expand the Indexes. There needs to be an automated Index defragmentation job that will either reorganize or rebuild the indexes based on the fragmentation level for a specific table in a specific database. 2. It doesn’t work on the intermediate pages between the root and the leaf. T-SQL Alter Index. – Ed B. Thanks for your. SQL Server Maintenance plans – Maintenance plans are shipped with SQL Server and are nice for some tasks. REORGANIZE seems to work as well as REBUILD all the time. A few thing to consider: Can you insert the data in the order of the index? This will reduce fragmentation. From this tab, select a SQL Server instance in the server explorer on the left and choose database (s) as a target of index operation. One can also reorganize an index using. avg_page_space_used_in_percent column in the sys. 2,057 11 22. Reorganize Index Log Generation Now here is the final demo of Reorganize the Index, it generates lots of Transaction Log records, a very simple demo, we will capture transaction log using sys. The documentation is also indicating that: Online index operations are not available in every SQL Server edition. We have an arguments saying Index rebuild not required if page count <1000 in MS SQL server. March 2, 2023 at 3:05 pm. Rebuilds automatically run statistics on your indexes. 11. below line will remove the NULL value from the query. If you're looking for whenif the index was ever rebuilt, the Ola sp does have the ability to log to a table and the previous DBA hopefully utilized this feature. Yup, that is one perfectly valid way. Shrink File. Many people (and even solutions) in the SQL Server community say you need to look at Index Fragmentation levels (e. When you double click on this task the following screen appears. ALTER INDEX ALL ON Adventureworks. So you should explicitly set a deadlock priority, and perhaps a retry loop, to enforce the behavior and document it. Online & Offline Index Rebuild. Er…. This means you can grant alter table on every table of interest that already exists. The query causing the block is in the format: ALTER INDEX [indexName] ON tableName REORGANIZE. Books Online for ALTER INDEX (Transact-SQL) Free index maintenance tool (and much more) Tags; index fragmentation;SQL Server 2016 allows customer to defragment this index using the familiar ALTER INDEX <index-name> REORGANIZE command instead of using a heavy hammer approach of rebuilding the index. This might be a good time to stop blindly rebuilding indexes. [Product] SET ( ALLOW_PAGE_LOCKS = ON ) ALTER INDEX [PK_Product] ON [Production]. (Look in the Misconceptions blog category for the rest of the month’s posts and check out the 60-page PDF with all the myths and misconceptions blog posts collected together when you join our Insider list, plus my online Myths and Misconceptions training course on Pluralsight. Cancelling / Stopping ALTER INDEX REORGANIZE. But commit your whole transaction before reorganize. You can still run the index reorg/rebuild as part of your maintenance scripts. Edit 2: Nikita added a good point on moving the data to a different filegroup as an option to exporting it outside SQL Server. Large objects (LOBs) are stored in different "pages". Reorgs require statistics run manually (exec sp_updatestats) From the description it sounds like a less intrusive operation and only less recommended because it's an older, slower process during which the DB will be less responsive. This allows you to interrupt the rebuild and preserve the work already done. To create a new job, right click on SQL Server Agent, select New and then Job. In this article. Connection. It has an IF condition for the Reorganize but i don't need it, i need to modify the code so it queries indexes of a certain database and schema and rebuilds only if the fragmentation is bigger than 5%. Bulk amount records are deleted and updated frequently. Over here it will display all the indexes of the table and you can just click OK. This schema modification lock blocks all other concurrent access to the table, but it is only held for a very short period of time while the old index is dropped and the statistics updated. To run the Maintenance plan, make sure your SQL server agent service is running. First of all you need to find the fragmentation percentage for the indexes in a database or table. 3. This caused the system to reorganize or rebuild. Msdn says: And also, avg_fragmentation_in_percent value says percentage of logical fragmentation (This is the percentage of out-of-order pages in the leaf pages of an index. Therefore, you do not need to update statistics after performing ALTER INDEX REBUILD, DBCC DBREINDEX, DBCC INDEXDEFRAG, or ALTER INDEX REORGANIZE operations. You can also slow down fragmentation by inserting data in the order of the index. #4156024. The fi rst factor is whether you have SQL Server Standard Edition or SQL Server Enterprise Edition. 2. DROP INDEX when. Expand the Tables folder. )You need to assemble the SQL prior to calling SP_ExecuteSQL, i. GO. dm_db_index_physical_stats dm function. Jonathan’s right in that fragmentation changes the query plan. The following index operations require no additional disk space: ALTER INDEX REORGANIZE; however, log space is required. The index it is running against is 78% fragmented. Yes it will - but only to a certain degree. reorganize pages. An index rebuild operation cannot be interrupted without it rolling back everything it’s done so far – it’s atomic – all or nothing. This will obviously alleviate both internal and external fragmentation but is a more heavy weight operation and by default causes the index to go offline, although it can be performed as an online operation, depending on your SQL. 7. If an index is between 10% and 30% fragmented, I will REORGANIZE the index and UPDATE the statistics. The Reorganize Index task reorganizes all indexes, regardless of fragmentation level. Applies to: SQL Server. For indexes you can drop them, shrink and then create. The script for the index itself: ALTER TABLE [dbo]. Surly not, the Maintenance Plan was created in the current Server itself. 1. SQL Server does not maintain when an Index was last rebuild, instead it keeps information when stats were last updated. Unlike REORGANIZE on user tables, REORGANIZE on a queue is always performed as an offline operation because page level locks are explicitly disabled on queues. indexstats. This procedure automatically chooses whether to rebuild or reorganize an index according to its fragmentation level, amongst other parameters, and update statistics. Prior to this index failing to reorganize, a different index (a non clustered unique index) on this table had this same error, and dropping and creating it fixed that one, but not this one. ” Select the vault database(s). The best practice recommendation is to reorganize your index if you have 5-30% of fragmentation, and only rebuild it if it has more than 30% fragmentation. Thanks, I will try this next time. 2. just like many things in RDBMS. dm_db_index_physical_stats in a script to rebuild or reorganize indexes). August 1, 2013 at 3:52 pm. Index fragmentation problem after disabling page-level locking for an Index. Therefore, focus on the larger indexes because their pages are less likely to be cached by SQL Server. 環境SQL Server 2012参考前回の以下の投稿に若干手を加えて作成しました。SQL Server の指定したテーブルのインデックス名を取得する方法ストアドプロシージャを実装するC…According to BOL:’In SQL Server 2005, sp_updatestats updates only those statistics that require updating based on the rowmodctr information in the sys. How can INDEX rebuilds be going parallel when MAXDOP is set to 1? They shouldn't be. These scripts are widely tested in the community and are much flexible so that you. Therefore you do not need to update statistics OR reorganize an index if it gets rebuilt. If an index contains less than 100 pages, I will perform no maintenance. SIMPLE mode only means the log space is made available for reuse after a transaction is committed. Inadequate disk space can degrade performance or even cause the index operation to fail. Oct 4, 202335. Proceed to the Steps tab: Clicking on New. Expand the table on which you want to reorganize an index. I am not sure I am picturing this correctly. [myTable] REORGANIZE WITH ( LOB_COMPACTION = ON ) I have the above query running for 16 days (still running), the table is a dummy table used for benchmark tests, it has over 10 Billion rows. Users(DisplayName) WITH (ONLINE = ON, RESUMABLE = ON, MAX_DURATION = 1); Those parameters mean: ONLINE = ON means you’ve got the money for Enterprise Edition. Maybe I am reading a different article - but what you linked to is actually worse. I would like to rebuild and reorganize my indexes, but our system works 24/7. 2. In earlier versions of Microsoft SQL Server it could cause system slowdown to reorganize or rebuild a large index. Oct 6, 2022 at 14:56 "I want to reorganize or. When you rebuild an index, SQL Server actually resorts the data of the index and uses a new set of index pages. 0 to SQL Server 2016 there is no feature to rebuild index automatically. I cannot understand the reason, can you ?. However, you can use the following methods to rebuild your indexes: Method 1: Create a SQL Server agent job to rebuild indexes and update statistics. The first steps of configuring the Reorganize Index task is quite similar to the Rebuild Index task. Rebuilding indexes is done using the following statement. The reason given is that the indexes and statistics are partly based on available CPU and memory resources. Hallengren website has an option to reorganize indexes say with 5% Fragmentation, and rebuild for 30% Fragmentation. allocation_units. Clean Up History. Use the ALTER TABLE command to rebuild the Heap. インデックスの断片化の状態がわかったら、それによってインデックス (index) を再構成 (Reorganize)するか、または再構築 (Rebuild) するか決定します。. When I run a maintenance plan to reorganize and rebuild tables indexes, it fails. Index rebuilds (not index reorganise) always do a fullscan update of the statistics. I wonder if there is just something weird about the way. This makes it more likely that some other session is blocked by your session, and that you may, in turn, become blocked by a lock held by that session. Make sure to thick the Enabled checkbox. Copied the LOB column to another table, dropped the column, re-created the column, and copied the data back (as outlined in this post: Freeing Unused Space SQL Server Table). Sumanta Roy (5/26/2011) Select Name as IndexName, STATS_DATE ( object_id , index_id ) as IndexCreatedDate. Thanks for your reply. This removes fragmentation, reclaims disk space by. ALTER INDEX REORGANIZE; however, log space is required. dm_db_index_physical_stats ‘ Dynamic Management View (DMV). 2. REORGANZE index - is for reducing fragmentation without index rebuild, so no drop and create. It eventually makes a Job in your server agent and then you can set a schedule or run the job manually by running this script. To solve this, I want to use the REORGANIZE operation every time. A clustered index exists, along with 3 non-clustered indexes. @LeeWalters shrink is done, and yes, due to disk issues, not possible to add drives, that's why, in addition, db is populated with blob data, so the question is more from the index fragmentation side. If the index you wish to reorganize is not listed in the “Indexes to be reorganized” section, ensure that it has been added to this section and then click the “OK” button. Reorganizing is designed to remove logical fragmentation from the leaf level of an index while keeping the index online and as available as possible. . Coming to update stats, I would prefer to do it with Full Scan depending on the size of the databases. The guidance from Microsoft is that indexes be rebuilt if the fragmentation is over 30% and reorganized if the fragmentation is between 5 and 30%. This is larger than the minimum row size. SQL Server Index Rebuild and Reorganize Script. REORGANIZES works by moving pages around, one at time. The. It doesn’t work on the intermediate pages between the root and the leaf. Here are a couple of examples. The Microsoft Docs page for SQL Server statistics states: Operations such as rebuilding, defragmenting, or reorganizing an index do not change the distribution of data. Select the server connection to use when performing this task. The purpose is to reduce the size of database and increase the db performance. こんにちは。開発部基幹SREチームの廣瀬です。 弊社では、システムの一部にSQL Serverを使用しています。 本記事では、SQL Serverにおけるインデックスのメンテナンス方法である再構成と再構築について、それぞれを実行した場合のクエリ性能の比較結果をご紹介したいと思います。 比較を実施. Note: You can select “Reorganize All” to reorganize all the indexes in the table. The discussion of columnstore indexes thus far has focused on clustered columnstore indexes that target a primarily OLAP workload. One of the possibilities that we have in SQL Server to keep our indexes defragmented, is the index reorganize operation. SQL Server internally does not keeps in any system table the fragmentation value so how it is going to decide what criteria to select when. 7. If rate of Index fragmentation increased then index de-fragmentation is become required. . If You have few indexes in. Identify and remove index fragmentation – this is obviously what we have been talking until now and the biggest part of the SQL index maintenance. . The discussion of columnstore indexes thus far has focused on clustered columnstore indexes that target a primarily OLAP workload. ALTER INDEX ALL ON table_name REBUILD OR. Let’s move on to creating the Reorganize Index task via the Maintenance Plans and then Update Statistics task. Modifying a SQL Server Maintenance Plan. Reorganizing should be used at lower (<30%) fragmentations but only rebuilding (which is heavier to the database) cuts the fragmentation down to 0%. Rebuild or Reorganize SQL Index. Okay, maybe not that. [<table_name>] REORGANIZE How to Reorganize and Rebuild Indexes using SSMS. I'm able to rebuild all other indexes with online=on option and it won't affect performance. If you are reindexing lots of large tables, the changes are still going to be logged and the log. Rebuild or reindex ?? good question ! Analysis indexes defragmentation RATIO and decide to REORGANIZE OR REBUILD. The size of one of the PK Clustered indexes is greater than 200GB, and for this one a REBUILD. Index automation Job script. This to me would be a sign that constant rebuilds of that index actually aren't a good help. Let it run. ALTER INDEX [PK_SalesOrderDetailEnlarged_SalesOrderID_SalesOrderDetailID] ON [Sales]. The SQL Server Database. But your index will also use more space. You should also include page_count value in your query. And that frequency can be lowered by using carefully selected fill factor. Here is the image for additional clarity. Sysjobhistory index "nc1" that is on job_id, its fragmentation does not go less than 66. Hi, We have SQL Server 2005 EE 62 bit with SP3. It reorgs indexes when fragmentation is below 30% else it rebuild the index. ALTER DATABASEdb_name SETREAD_COMMITTED_SNAPSHOT ON go Alter index Index_name on table_name. All versions of SQL Server 2008 Management Studio create the index with page level locking enabled by. Index fragmentation increased significantly after rebuild. The Reorganize Index task encapsulates the Transact-SQL ALTER INDEX statement. In SQL Server Management Studio, in Object Explorer, expand the server. When you reorganize the index, you go through the existing index, cleaning up blocks for deleted records etc. dm_exec_requests to see how much longer your query has to finish. Reorganizing an index uses minimal system resources. Although this option increases the amount of temporary disk space that is used to create an index, the. Applies to: SQL Server SSIS Integration Runtime in Azure Data Factory The Rebuild Index task rebuilds indexes in SQL Server database tables and views. 1. You can add a rebuild index task or reorganize index task into the maintenance plan, but the problem is that you can't really apply any logic to the plan. A table may only have one columnstore index on it at a time, regardless of whether it is clustered or nonclustered. Hi, Added an index maintenance job (Hallengren) to a database (SQL Server 2016) with a few large tables. Sorted by: 1. There are a number of differences. sysindexes compatibility view; therefore, preventing unnecessary updates of unchanged items. The execute sql task should contain the index rebuild code along with stats rebuild . Here's another script to add to the list. Microsoft Certified Master: SQL Server, MVP, M. . ”. x)) e Banco de Dados SQL do Azure, REORGANIZE executa as seguintes otimizações adicionais desfragmentação online: Remove fisicamente linhas de um grupo de linhas quando 10% ou mais linhas foram excluídas logicamente. So we can use index reorganize option to rebuild all the indexes. For example, the heaviest index (clustered index and also pk) is running reorg for around 4 hours 30 min even do the. Useful links. Exclusive page locks are taken on individual pages only while those pages are being manipulated. When investigating we found that the index reorganise for the clustered index of FooDetail takes between 90 minutes and 120 minutes. #1637994. " But following the Russ's reply the REORGANIZE is a more time expensive operation the REBUILD one. However, a new database server backed with Intel PCIe SSDs is showing the opposite of what we expect. dm_db_index_physical_stats system dynamic management function which returns a list of indexes created on SQL Server instance with enough information for a database admin to decide if the sql index is fragmented or not. the reorganize index also facing some problem like it is successfull once in three runs and twice it is failing. some action needs to be taken to remove the ghosted records. With dbForge Index Manager, you can instantly rebuild and reorganize SQL Server indexes in visual mode or generate SQL scripts for future use. It also lets you specify a LOB_COMPACTION option. The MAXDOP index option cannot be specified in the ALTER INDEX REORGANIZE statement. REORGANIZE Tells SQL Server to perform a master merge, which involves merging the smaller indexes created in the process of indexing into one large index. SQL Server 2016 (13. I am getting confused with choosing Index Reorganize/Rebuilding of indexes based on avg_fragmentation_in_percent returned by sys. Frequency of the maintenance should be considered with the goal of minimizing impact of log generation. So any insert in the middle of the key range, and likely any update too, will cause a page split and fragmentation. Failing that (ie Standard Edition etc), look at re-organizing indexes - these will keep them online. Use the page count reported by DBCC SHOWCONTIG to get an idea of the size of the indexes (each page is 8 KB in size). Another possibly is that the index is being rebuilt and then re-fragmenting again. Large object data is data with the image, text, ntext, varchar (max), nvarchar (max), varbinary (max), or xml data type. dbForge Index Manager for SQL Server will. These pages can get empty space on them and become out of order over time as well. Exclusive page locks are taken on individual pages only while those pages are being manipulated. The first part of this tip focuses on SQL Server Enterprise Edition to reduce the duration for index maintenance for off-line rebuilds. This means that an index can be rebuilt without knowing the structure. Please post more details like how are you running the reorganize via TSQL or SSMS or SSIS. index rebuild/reorganize frequency. Mohamad Mahmoud Darwish. The link points to SQL Server 2014 docs, but the syntax should work on 2005 and 2008 as well. However, my SQL Server license is Standard and I can't rebuild indexes online. dm_db_index_physical_stats (under the Examples -> D section: Using sys. dm_db_index_physical_stats (Transact-SQL). To execute our task, we can right-click on the plan and choose Execute. The transaction log backup size spikes during index reorganize - exponentially bigger. the year and month columns. The second set of options, in figure 8-5, rebuilds only a single partition of a clustered columnstore index and optionally changes the compression type. @OnlyModifiedStatistics = 'Y'.