Reorganize index sql server. A developer coming onto a project with out of date tools is a common cause of this. Reorganize index sql server

 
 A developer coming onto a project with out of date tools is a common cause of thisReorganize index sql server  ALTER INDEX ALL ON [table_name] REORGANIZE; However, if you want to rebuild all the indexes on the table, you can run the following

Index should be reorganized when index fragmentation is between 10% to 40%. Executing this query requires the VIEW SERVER STATE permission. SQL Server. So you should explicitly set a deadlock priority, and perhaps a retry loop, to enforce the behavior and document it. line is helpful to give the user some indication of what indexes it is rebuilding and how far it has progressed. SQL Server Index Rebuild and Reorganize Script. Add a comment. I used this approach to improve performance and it worked perfectly for a long time. ALTER INDEX [myIndex] ON [dbo]. First it’ll try an index reorganize, which is an online operation. The performance benefit may not be noticeable for indexes that are used primarily for seek operations. PARTITION Only rebuild/reorganize one partition of the index. Rebuilding your indexes will slow queries down. 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. Until now I'm using the Maintenance Plan Index rebuild task to. Sc (Comp Sci) SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability. By using the Rebuild Index task, a package can rebuild indexes in a single. Reorgs defragment the leaf level of clustered and. Expand the Tables folder. Just a reminder that index reorganize is always online (all indexes are available during defrag) and index rebuild can be made also online (WITH. This to me would be a sign that constant rebuilds of that index actually aren't a good help. 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. Test all three and see which is fastest and which gives the least index fragmentation. In decades of working with MS SQL Server at a many companies, I've never ONCE had to rebuild the indexes in order to fix a performance problem. There are two options to fix fragmentation. . 7. As you've seen, shrinking your database causes high levels of index. In other words, zero percentage fragmentation:. Then monitor and tweak jobs in a way that is appropriate to. 7. You can always update statistics on their own. The Page Fullness is 98. One can also reorganize an index using. 1 Answer. DBCC DBREINDEX - use to re-index with older versions (SQL Server 2000 and earlier) sys. dm_db_index_physical_stats (NULL, NULL, NULL, NULL, NULL); GO. The process uses the existing pages only and does not allocate new ones, but it does compact the index pages. Rebuilding an index can be either an online operation or an offl ine operation, depending on several factors. 3. Depending on the fragmentation level, you need to rebuild or reorganize the indexes. Plan B is fine. SQL Server 2019 adds resumable online index creation, and it’s pretty spiffy: 1. 3,895 9 51 77. Sorry No idea why this happened. Rebuilding basically creates an entirely new copy of the index, and is much more effective at reducing fragmentation - but this comes at a cost, both in terms of time and disk space. sql to our customers's SQL Server instance. Deletes catalog and creates new. Over time these modifications can cause the information in the index to become scattered in the database (fragmented). Index Maintenance is one of the major task for a DBA. TEST REORGANIZE WITH. Quick explanation: An online Rebuild, rebuilds the indexes on the tempDB making it available to the queries while it is being rebuilt. And also, avg_fragmentation_in_percent value says percentage of logical fragmentation (This is. I have been advised by a contracted SQL Server expert that, after any change in # of CPUs and/or available memory, I should reorganize all indexes and then update all statistics or SQL Server will. 例えば、10 % 以上 30 % 未満であれば再構成 (Reorganize)、 30% 以上であれば再構築 (Rebuild) するとすれば、上記の. The index uses the main filters on the sales table from the time dimension, i. 1. 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. REORGANIZE, but shrink is going to take an age, and then you’ll generate a ton of log doing the fragmentation removal. ALTER INDEX REORGANIZE statement is always performed online. Product REBUILD GO Index Reorganize : This process physically reorganizes the leaf nodes of. Reorganizing the indexes will take less time, and less effort from the SQL server thus they can be done in a weeknight type of instances. Please refer to SQL Server Maintenance Plan Reorganize Index and Update Statistics Tasks to get more information about how to design the maintenance plan. The problem is that the size is getting out of control, I can see up to 99% fragmentation in the Primary Key clustered indexes. The more the fragmentation you need to rebuild if its less you can reorganize. Any helps to me, please? Thanks · REORGANIZE is always an online operation, that is, it does not block. Index Reorganize During Database Full Backup. Microsoft Certified Master: SQL Server, MVP, M. A table may only have one columnstore index on it at a time, regardless of whether it is clustered or nonclustered. In it, enter the Job name, owner, optionally Category. ALTER INDEX [PK_SalesOrderDetailEnlarged_SalesOrderID_SalesOrderDetailID] ON [Sales]. T-SQL Alter Index. It is compatible with all versions of SQL Server 2005 , 2008 , 2012 , 2014 and 2016. If page_count value ( which is there in DMV sys. This tool provides index analysis to manage index defragmentation, including rebuild and reorganize fragmented indexes . Regards. avg_fragmentation_in_percent FROM sys. Here is a procedure what I wrote. Merging the full-text index fragments can improve performance and free up disk and memory resources. The query causing the block is in the format: ALTER INDEX [indexName] ON tableName REORGANIZE. TEST REORGANIZE We get our open delta store again, which will cause locking. Index rebuilding process uses more CPU and it locks the database resources. The Reorganize Index task also includes an option to compact large object data. Rebuild or Reorganize SQL Index. There are two main ways to defragment a Heap Table: Create a Clustered Index and then drop it. Designing the SQL Server Reorganize Index Task. g. You should also include page_count value in your query. You should intelligently do index reorg and rebuilds. Backup Up Database (Full)4. Index maintenance such as index rebuilds are also a wasteful operation. DBCC DBREINDEX rebuilds an index for a table or all indexes defined for a table. Both create/rebuild of columnstore index is an OFFLINE operation at this time but you can defragment columnstore index ONLINE. USE AdventureWorks; GO ALTER INDEX ALL ON Production. sysindexes compatibility view; therefore, preventing unnecessary updates of unchanged items. Bad internal fragmentation (having lots of free space on the pages) means the index is bigger than it needs to be. Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance When you perform online index operations, the following guidelines apply: Clustered indexes must be created, rebuilt, or dropped offline when the underlying table contains the following large object (LOB) data types: image, ntext, and text. REORGANIZE, UPDATE STATISTICS and a simple SELECT statement. [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. Here are a couple of examples. Recall the paper example from above: a rebuild would be like reprinting the document in the correct order and trashing the old ones. Execute SQL Server Agent Job. You can do maintenance in phases, where each maintenance phase covers a subset of. Method 2: Set Change_Tracking to Manual, by using the following command: ALTER FULLTEXT INDEX ON table_name set Change_tracking = Manual Then, create SQL Server jobs to spread. You can also slow down fragmentation by inserting data in the order of the index. Remarks. A developer coming onto a project with out of date tools is a common cause of this. Therefore, you do not need to update statistics after performing ALTER INDEX REBUILD, DBCC DBREINDEX, DBCC INDEXDEFRAG, or ALTER INDEX REORGANIZE operations. The issue is resolved. The answer is: it depends. ALTER INDEX ALL ON table_name REORGANIZE OR. It reorgs indexes when fragmentation is below 30% else it rebuild the index. You can also see if a reorganize will help until you can do a full rebuild. In this case you can perform index reorganize and index rebuild operations only on those partitions that really need it, thus making it more efficient by reducing the time and resources needed for this maintenance. A REORGANIZE physically reorders the leaf-level pages to match the logical order of the leaf nodes, whereas a REBUILD does just that, it rebuilds the index. index_id > 0 -- Indexes. Right-click the Indexes folder and select Reorganize All. Or if it swapping places of two pages. I made them up. Index fragmentation increased significantly after rebuild. Mohamad Mahmoud Darwish. Example #. Surly not, the Maintenance Plan was created in the current Server itself. Mar 8, 2021, 2:47 PM. Use the Reorganize Index task followed by the Update Statistics task; If you have the Enterprise Edition of SQL Server, the Maintenance Plan Wizard offers a Keep index online while reindexing option, which means that the index will continue to be available to users even while it is being rebuilt. Even though this is an online activity, you. For indexes you can drop them, shrink and then create. If your indexes are fragmented : If index has less than 1000 pages - do not perform any index maintenance operation. 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. Many people (and even solutions) in the SQL Server community say you need to look at Index Fragmentation levels (e. If the page_count is less than 1000 (or whatever you decide) then you should ignore the index. If you use Ola Hallegren's scripts then you can set the thresholds for a rebuild/reorganise (say over 50% fragmentation for a reorganise, over 80% for a rebuild) and this can run overnight out of hours. 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. I cannot understand the reason, can you ?. 23%. Thanks for your reply. Online index rebuild higher fragmentation on intermediate level. Remarks. x) and in Azure SQL Database, we recommend using ALTER. ApexSQL Defrag is a powerful application used for scheduled analyzing and defragmenting of SQL Server database indexes. A nonclustered columnstore index. 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。. In the infrequent cases where you do need to reorganize or re-build index, consider these: Run index maintenance during off peak period. In SQL Server Management Studio, in Object Explorer, expand the server. Compaction is based on the existing fill. 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. This means you can grant alter table on every table of interest that already exists. Note that the time it takes to complete the operations depends on the size of the database and how fragmented the indexes. That can be found using the STATS_DATE function. In this article. It doesn't work the way you think it does. dm_exec_requests showed the REORG was only 55%. The tool allows you to quickly collect index fragmentation statistics and detect databases that require maintenance. e check fragmentation and take an appropriate action. ALTER INDEX [PK_SalesOrderDetailEnlarged_SalesOrderID_SalesOrderDetailID] ON [Sales]. Use the ALTER TABLE command to rebuild the Heap. Larger indexes have more intermediate levels and pages. So any insert in the middle of the key range, and likely any update too, will cause a page split and fragmentation. An index can become fragmented over time as data is added, updated, or deleted, and this fragmentation can lead to longer query execution times and decreased performance. SQL SERVER – Difference Between Index Rebuild and Index Reorganize Explained with T-SQL Script. Hi all, I have SQL Server 2017 Edition and see harmful fragmentation for all tables in DB. 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. Method 2: Manually create rebuild job using scripts and scheduled as. Similarly, removing. Should be straight forward. 1. > 5% and < = 30% ALTER INDEX REORGANIZE. Sc (Comp Sci). However, recently this approach has. This opens the Toolbox and the maintenance_plan_name [Design] surface with the Subplan_1 subplan. This task uses the ALTER INDEX REORGANIZE statement with SQL Server databases. I also removed the the second part of the case statement that uses REORGANIZE. ALTER INDEX CCI_TEST on DBO. 1. However, my SQL Server license is Standard and I can't rebuild indexes online. The Reorganize Index task encapsulates the Transact-SQL ALTER INDEX statement. You also can create a linked server to SQLAZURE and create a sql agent job. This is great if you want to release some space quickly. indexstats. Next the New Job window will open. It will have a parameter called @MaintenanceMode that can be set to either ‘INDEX’ or ‘CATALOG’ in order to choose the way we want to maintain our Full-Text indexes. Additionally, after reorganizing indexes it is reasonable to update the statistics as this operation does not update the statistics like the index rebuild operation. 1. Statistics on indexes automatically get updated. By allowing an index to be rebuilt dynamically, indexes enforcing either PRIMARY KEY or UNIQUE constraints can be rebuilt without having to drop and re-create those constraints. For now, I have just turned off the weekly index reorganize task which is not really a good long term solution. I wonder if there is just something weird about the way. Sorted by: 5. REORGANIZE cannot be specified for a disabled index or. ALTER INDEX ALL ON [dbo]. We use SQL Server Index Rebuild and Reorganize operation to remove fragmentation level of the indexes. For example, the heaviest index (clustered index and also pk) is running reorg for around 4 hours 30 min even do the. regarding index rebuild or reorganize for system database **I do not see a need** out of all system databases, tempdb is recreated whenever SQL Server service starts, Model is used as a template database. Indexes play a vital role in the performance of SQL Server applications. Bug in Rebuild on SQL Server 2016 and above? 6. Online rebuilds are online available on the Enterprise version of SQL Server and your version probably isn't, so just set the operation not to be run "Online" on you Wizard. Total fragmentation is 96% page fullness 66%, avg row size is 20,. 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). This means that an index can be rebuilt without knowing the structure. 3. We will call this stored procedure Maintenance. ALTER INDEX ALL ON [table_name] REORGANIZE; However, if you want to rebuild all the indexes on the table, you can run the following. To solve this, I want to use the REORGANIZE operation every time. set @SQL = 'alter index ' + QuoteName ( @IndexName ) + ' on ' + QuoteName ( @TableName ) + ' rebuild';. Shrink File is. Script to reorganize all indexes on all tables in user databases. All versions of SQL Server 2008 Management Studio create the index with page level locking enabled by. Some operations that took ~90s now take ~6mins. Clean Up History. From Reorganize and Rebuild Indexes. Index rebuilding and reorganizing are the two methods to maintain indexes and improve database performance. Applies to: SQL Server. Or considering avoiding index rebuilds in favor of statistics updates. . When you reorganize an index, SQL Server physically reorders the leaf-level pages to match the logical order of the leaf nodes. Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW) Poorly designed indexes and a lack of indexes are primary sources of database application bottlenecks. Therefore, focus on the larger indexes because their pages are less likely to be cached by SQL Server. every 2-3 day if running maintenance once per day (night). 1. 8. Whether you rebuild or reorganize indexes depends on the following guidelines: avg_fragmentation_in_percent value Corrective statement. If you are reindexing lots of large tables, the changes are still going to be logged and the log. By allowing an index to be rebuilt dynamically, indexes enforcing either PRIMARY KEY or UNIQUE constraints can be rebuilt without having to drop and re-create those constraints. When investigating we found that the index reorganise for the clustered index of FooDetail takes between 90 minutes and 120 minutes. Clean Up History. For maintenance i create a procedure that: -Shrink Database file (if is enabled) -Shrink Database log file. – Ed B. record_count > 0 AND o. 11. Creating or dropping the table’s clustered index causes all its nonclustered indexes to be rebuilt. REORGANZE index - is for reducing fragmentation without index rebuild, so no drop and create. This script has been tested and will work with SQL Server 2005, SQL Server 2008, SQL Server 2008R2, SQL Server 2012, SQL Server 2014, SQL Server 2016, SQL Server 2017 and SQL Server 2019. Here's another script to add to the list. ALTER INDEX ALL ON [table_name] REORGANIZE; However, if you want to rebuild all the indexes on the. Yes, rebuilding indexes will take a toll on your transaction log file. Rebuilding an index does two things. Factors to consider while Rebuild/Reorganize of index in SQL Server 2012. ALTER INDEX CCI_TEST on DBO. Rebuild Indexes. The transaction log backup size spikes during index reorganize - exponentially bigger. 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. In SQL Server, when rebuilding an index which previously had statistics updated with PERSIST_SAMPLE_PERCENT, the persisted sample percent is reset back to default. Check indexes from the index grid and click desired defragment operation from the ribbon. The size of one of the PK Clustered indexes is greater than 200GB, and for this one a REBUILD. You can even stagger which indexes get rebuilt when and perhaps pick the top N index, based on fragmentation level, and REORGANIZE a certain number of them each night. SQL Server, MVP, M. For example, one of the indexes with a page_count of 967 has a fragmentation percentage of 98,98%! To me, it seems worth rebuilding that index! I did, and afterwards, the fragmentation was 0%. As a good start, read these: Rebuild or Reorganize: SQL Server Index Maintenance (Kendra Little)“Reorganize” index option. It’s advisable to remove those often. The Reorganize Index task also includes an option to compact large object data. 1. Below is an example of this technique, where the @PartitonNumber value can be changed in a restart scenario. This REBUILD option is available in SQL Server 2008 onwards. Reorganize all index in SQL Server. The purpose is to reduce the size of database and increase the db performance. Rebuild or Reorganize SQL Index. 000. However, imagine that you have seven years of data. " But following the Russ's reply the REORGANIZE is a more time expensive operation the REBUILD one. ALTER INDEX [PK_SalesOrderDetailEnlarged_SalesOrderID_SalesOrderDetailID] ON [Sales]. Failing that (ie Standard Edition etc), look at re-organizing indexes - these will keep them online. It doesn’t work on the intermediate pages between the root and the leaf. An index rebuild will always build a new index, even if there’s no fragmentation. ;WITH cte AS ( SELECT object_id, index_id, partition_number, rows, ROW_NUMBER () OVER (PARTITION BY object_id, index_id, partition_number. allocation_units. The execute sql task should contain the index rebuild code along with stats rebuild . This tool provides index analysis to manage index defragmentation, including rebuild and reorganize fragmented indexes . For the data (clustered index and heap) you'd have to export outside SQL Server, truncate the table, shrink and then import the data. #4156024. Microsoft's guidance on index reorganize and rebuild supports this: For example, if a given index is used mainly for scan operations, removing fragmentation can improve performance of these operations. dm_tran_database_transactions DMV:SQL: Procedure for rebuild and reorganize indexes like Microsoft says. This is because the Rebuild Index task will destroy all the indexes and build it again from scratch, without considering the fragmentation percentage. [Test] REBUILD WITH (ONLINE = ON); Additionally, I would only rebuild indexes which require it. As a result of rebuilding an index, SQL Server also updates the statistics for the indexes that were rebuilt. The fill factor determines the amount of empty space on each page in the index, to accommodate future expansion. Unless you are adding data exactly in the order of the index the index will fragment. The following example returns all statistics for all tables and indexes within the instance of SQL Server by specifying the wildcard NULL for all parameters. Index reorg only shuffles around leaf-level pages of your index and will try to compact those - but it doesn't completely rebuild the index structure. Reorganizing an Index should be done when you have elevated amounts of white space within your index (i. 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. If the command that's running is a reorg, you can just kill it. Microsoft recommends Index Rebuild operation to defrag indexes if the fragmentation level of your index is greater. I'd like to propose to use REORGANIZE index and so I need to tell the related real benefits. dbo. For more information, see sys. I don't think Windows SQL Server Maintenance has this option yet. As a generally accepted good practice reorganize only when ragmentation of index is between 5 to 30 % for anything more than that rebuild the index. If the index is disabled, rebuilding brings it back to life. Answers. : 15% com. It is used when the operation takes a. Microsoft's guidance on index reorganize and rebuild supports this: For example, if a given index is used mainly for scan operations, removing fragmentation can improve performance of these operations. I suspect the reorganize is compacting the index after the rebuild and thus moving quite a bit of data around. 1. Expand Tables. e. It was trying to do so because when. When you. So far, all good. You can also change this threshold via parameters. •DatabaseBackup: SQL Server Backup •DatabaseIntegrityCheck: SQL Server Integrity Check •IndexOptimize: SQL Server Index and Statistics Maintenance. Either can allow maintaining a high average percent full in the data. ” Select the vault database(s). The MAXDOP index option cannot be specified in the ALTER INDEX REORGANIZE statement. 3. Options. These pages can get empty space on them and become out of order over time as well. Also, in earlier versions the granularity of control was less refined. But, fill factor is defined in index properties, and is not overriden in index rebuild settings, so I believe both operations should respect the value. This method can help when Change_tracking is Auto. These tables are updated daily. SQL Server 2005 Index Rebuild/Reorganize. line is helpful to give the user some indication of what indexes it is rebuilding and how far it has progressed. This is typically how indexes with page level locking disabled get created. -Search all indexes of a table that have 5% or more of fragmentation and page_count >= 1000. Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance. Index Rebuild operation first drops and then recreates the index. Listing 8-5: Rebuild the clustered columnstore index over a clustered rowstore index. 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 a table has multiple indexes, create the clustered index first, then the nonclustered. Problem. There are two options to fix fragmentation. Syntax ALTER INDEX index_name ON table_name. Below the last two rows that displays the fail: Source: Reorganize Index Executing query "ALTER INDEX [PK_xxTableName] O. This might be a good time to stop blindly rebuilding indexes. 0. When you rebuild, SQL creates a new fresh index. Correct way of maintenance of SQLServer Cluster Columnstore Index. For higher fragmentation Rebuild is preferred. This job needs to be scheduled and ran on a weekly basis due to large data load. I have been advised by a contracted SQL Server expert that, after any change in # of CPUs and/or available memory, I should reorganize all indexes and then update all statistics or SQL Server will not make the full use of the new resources. A clustered index exists, along with 3 non-clustered indexes. For information about how to maintenance index, refer to MS document. Reorganizing only works on the leaf pages. SQL Server (SQL Server 2016 (13. dm_db_index_physical_stats function is avg. The database is using the Simple Recovery model. Using above query, you could also query the progress of backup,restore,dbcc command and so on. The script for the index itself: ALTER TABLE [dbo]. How Fragmentation Hurts SQL Server Performance. Yup. Reorganize all indexes on the queue internal table. Identify and remove index fragmentation – this is obviously what we have been talking until now and the biggest part of the SQL index maintenance. If you specify the hint. This topic describes how to reorganize or rebuild a fragmented index in SQL Server 2017 by using SQL Server Management Studio or Transact-SQL. If you cancel a rebuild operation midway, it. Parallel index execution and the MAXDOP index option apply to the. An index reorganize holds an intent-exclusive table lock throughout the operation, which will only block shared, exclusive, and schema-modification table locks. This had a negligible impact. Next Steps This is a simple base script that could be modified into a stored procedure and also allow you to pass other parameters such as doing an index. The equivalent statistics update can be achieved by: UPDATE STATISTICS . The documentation for alter index, for example, shows that it accepts an index_name, not an expression that might evaluate to an index name. You should always do some form of intelligent rebuilding - i. This blog entry I came across a while back will explain it much better than I can. 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. @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. Reorganizing an index uses minimal system resources. So it can remove some fragmentation - but only on a limited scale. Applies to: SQL Server SSIS Integration Runtime in Azure Data Factory The Rebuild Index task rebuilds indexes in SQL Server database tables and views. ALTER INDEX [myIndex] ON [dbo]. 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. Usually, you should rebuild the index if it has a fragmentation greater than 30% and reorganize it if it has less than 30% fragmentation. Object: SQLServer:Databases; Counter: Percent Log Used ; Instance: (your big database name) Alert if counter rises above: 80; Response: Execute job ('Reorganize Check') Create a job ('Reorganize Check')In this article. Largest table has around 500. 5% to 30% -> ALTER INDEX REORGANIZE Over 30% -> ALTER INDEX REBUILD WITH (ONLINE = ON)* However, we have noticed that even with really high fragmentation (over 95%) on large and small tables, REORGANIZE works fine. Index Rebuild : This process drops the existing Index and Recreates the index. March 2, 2023 at 3:05 pm. You can query the sys.