Reorganize index sql server. OBJECT_ID) AS TableName, ind. Reorganize index sql server

 
OBJECT_ID) AS TableName, indReorganize index sql server Factors to consider while Rebuild/Reorganize of index in SQL Server 2012

Create jobs to automate maintenance – create a SQL Server Agent job that will automate SQL index maintenance. This is great if you want to release some space quickly. When you. April 1, 2009 at 5:07 am. : 15% com. Click OK. Index fragmentation problem after disabling page-level locking for an Index. You have to do some research and tailoring of how and when to do it based on your environment, though. For example, the heaviest index (clustered index and also pk) is running reorg for around 4 hours 30 min even do the. Reorganize or rebuild an index SQL Server Management Studio. ALTER INDEX . How can INDEX rebuilds be going parallel when MAXDOP is set to 1? They shouldn't be. I'd just add that adding the line PRINT @sql after the SET @sql =. 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. Reorganize (SQL Server indexes, primary keys, and unique keys) The Reorganize Indexes dialog lets you reorganize an entire index, primary key, or unique key or a single partition of that object. Factors to consider while Rebuild/Reorganize of index in SQL Server 2012. 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. No right from SQL Server 7. 2. ALTER INDEX CCI_TEST on DBO. An index reorganize holds an intent-exclusive table lock throughout the operation, which will only block shared, exclusive, and schema-modification table locks. Here's another script to add to the list. If the page_count is less than 1000 (or whatever you decide) then you should ignore the index. If you want to fully automate your SQL Server Index maintenance then I seriously recommend that you check out Michelle Ufford's stored procedure for this. Sysjobhistory index "nc1" that is on job_id, its fragmentation does not go less than 66. Frequency of the maintenance should be considered with the goal of minimizing impact of log generation. In SQL Server, you "might" run into issues with "updating primary key". 2 Answers. Compaction is based on the existing fill. If you what you are saying is true, even reorganizing the. 1. Online index rebuild higher fragmentation on intermediate level. Any helps to me, please? Thanks · REORGANIZE is always an online operation, that is, it does not block. 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. I would suggest that you use Ola Hallengren's scripts, freely available and widely used. We can however get it back to a compressed segment by issuing the following command we saw previously. The index uses the main filters on the sales table from the time dimension, i. Reorganizing or rebuilding a cluster index does not have any impact on the non-cluster indexes in SQL Server 2000 SP4 or above, or any version of SQL 2005 or. Let it run. SQL Server Maintenance plans – Maintenance plans are shipped with SQL Server and are nice for some tasks. every 2-3 day if running maintenance once per day (night). REORGANIZE seems to work as well as REBUILD all the time. sql to our customers's SQL Server instance. e. 2) Extra disk space required during SQL Server online index rebuilds. Expand the Tables folder. There are two main ways to defragment a Heap Table: Create a Clustered Index and then drop it. Index rebuilds (not index reorganise) always do a fullscan update of the statistics. 3. Designing the SQL Server Reorganize Index Task. How Fragmentation Hurts SQL Server Performance. Basically, an index rebuild copies the index to another place. PARTITION Only rebuild/reorganize one partition of the index. Either can allow maintaining a high average percent full in the data. 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. RCSI utilizes tempdb heavily but gives performance boost. Please refer to SQL Server Maintenance Plan Reorganize Index and Update Statistics Tasks to get more information about how to design the maintenance plan. They are also configured from SSMS. 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. The first and most popular method is to rebuild indexes. 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. . A developer coming onto a project with out of date tools is a common cause of this. Index rebuilding and reorganizing are the two methods to maintain indexes and improve database performance. One thing to ask! When I reorganize MSDB. Online & Offline Index Rebuild. [<table_name>] REORGANIZE How to Reorganize and Rebuild Indexes using SSMS. Reorganize Index. Select Allow online DML processing, and then select True from the list. ALTER INDEX [myIndex] ON [dbo]. First you need to create a maintenance plan and select the "Rebuild Index Task" option as shown below. Obviously this isn't the same as index reorganize, so I'm still trying to think what does reorganize file technically mean. Reorganizing is designed to remove logical fragmentation from the leaf level of an index while keeping the index online and as available as possible. sysindexes compatibility view; therefore, preventing unnecessary updates of unchanged items. This REBUILD option is available in SQL Server 2008 onwards. – variable. Thanks for your. This blog entry I came across a while back will explain it much better than I can. Disk space is an important consideration when you create, rebuild, or drop indexes. Or if it swapping places of two pages. Yes. The more the fragmentation you need to rebuild if its less you can reorganize. The first rebuilds a single index on a table and the second rebuilds all the indexes on the table. As you've seen, shrinking your database causes high levels of index. We have a database server (2016 SQL Server), that we have added a step of 'rebuilding indexes' to the deployment process. If the command that's running is a reorg, you can just kill it. Wouldn’t rebuilding an index with MAXDOP=4 on a heavily utilized SQL Server result in the index being (again) fragmented after the rebuild? This could happen in the case where they’re a lot of statements waiting to be processed and the database engine assingning the subtasks of the index reorganize in portions to different queues. Which is the best method to reorganize sql server database. #4156024. Sumanta Roy (5/26/2011) Select Name as IndexName, STATS_DATE ( object_id , index_id ) as IndexCreatedDate. The. We are using clustered columnstore index in SqlServer 2016 for 400M rows. > 5% and < = 30% ALTER INDEX REORGANIZE. So, whenever I need to rebuild the indexes of my OrdersItemstable, with some millions of rows, my customers can't create/edit new orders for about 2-4 minutes. MS advises using Reorganize for 30% fragmentation or less. Reorganize Index. IndexOptimize is the SQL Server Maintenance Solution’s stored procedure for rebuilding and reorganizing indexes and updating statistics. Maybe I am reading a different article - but what you linked to is actually worse. Applies to: SQL Server. To create SQL Server agent that will defragment specified indexes automatically, perform the following steps: Expand SQL Server Agent in Object explorer, right click on Jobs, and select New Job…: In General tab, specify the name and description for the job. Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW) Columnstore indexes are the standard for storing and querying large data warehousing fact tables. 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. Sc (Comp Sci). Rebuild of indexes is the prime job of a DBA as heavily fragmented indexes can degrade query performance and cause your application to respond slowly. Reorganize an index For rowstore indexes, the Database Engine defragments only the leaf level of clustered and nonclustered indexes on. reorganize pages. The script for the index itself: ALTER TABLE [dbo]. Index rebuilding process uses more CPU and it locks the database resources. 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. Therefore, you do not need to update statistics after performing ALTER INDEX REBUILD, DBCC DBREINDEX, DBCC INDEXDEFRAG, or ALTER INDEX REORGANIZE operations. Starting from SQL Server 2016, new options were added to the index maintenance tasks that allow us to perform the Rebuild Index and Reorganize Index tasks, based on the fragmentation percentage of the index, and other useful options to control the index maintenance process. This. Because I was blamed for the slow SQL Server mainly because I. 000. My problem is that the reorg is running for a very long time. 1 Answer. ALTER INDEX [PK_SalesOrderDetailEnlarged_SalesOrderID_SalesOrderDetailID] ON [Sales]. Shrinking is a wasteful operation. every 2-3 day if running maintenance once per day (night). Rebuilds automatically run statistics on your indexes. I know the sql to perform this action on all indexes in a table is alter index all on table_name reorganize; But I only want to rebuild or reorganize if . 6. Thanks for your reply. Rebuild Index. I was going to take a look at Ola Hallengren 's scripts and some other stuff but wanted to see if there was possibly a simple explanation for this. REORGANIZE, UPDATE STATISTICS and a simple SELECT statement. Yes. 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. If you search for index rebuilding, you will find many complex scripts on the web, but this can also be done. You can also see if a reorganize will help until you can do a full rebuild. Similarly, removing. From sys. Our Production instance is running SQL Server 2014. First, we will start the index reorganization in a session using the following T-SQL code. 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. NAME 'Table name', i. Right-click the Maintenance Plans folder and select New Maintenance Plan. Larger indexes have more intermediate levels and pages. From Reorganize and Rebuild Indexes. As per followed practice you can rebuild index when fragmentation is >30 % and can reorganize when fragmentation is between 10 and 30 %. Remarks. We leave default values here as well. 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. I also removed the the second part of the case statement that uses REORGANIZE. Connection. This article *recommends* REORGANIZE as the primary method to be used and then links to code that uses the same. Otherwise you're holding an exclusive lock on the table/partition before you start the reorganize. 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. If an index is between 10% and 30% fragmented, I will REORGANIZE the index and UPDATE the statistics. Product REBUILD GO Index Reorganize : This process physically reorganizes the leaf nodes of the index. SQL. 8. Over here it will display all the indexes of the table and you can just click OK. set @SQL = 'alter index ' + QuoteName ( @IndexName ) + ' on ' + QuoteName ( @TableName ) + ' rebuild';. Remarks. ALTER INDEX [name_of_the_index] ON [table_name] REORGANIZE; If you want to reorganize all the indexes on any table, you can run the following syntax. ApexSQL Defrag tool is a 3 rd party SQL index defragmentation tool that you can easily use to perform number of operations related to the SQL Server indexes. SQL Agent doesn't connect as SA, and the rebuild index task generates a command that looks like ALTER INDEX [ci_FactInternetSales] ON [dbo]. Although this option increases the amount of temporary disk space that is used to create an index, the. dm_db_index_physical_stats(DB_ID(), NULL, NULL, NULL, NULL) indexstats INNER JOIN sys. Basically every hour I query the dm_db_index_physical_stats dynamic management view and if an index is between 5% and 30% fragmented I. Index automation Job script. Example #. SQL Server 2005 Index Rebuild/Reorganize. Right-click on Maintenance Plans and select New Maintenance Plan…. I'm currently using the approach described here: sys. Index Defrag Script V4. If you want to rebuild an index the syntax is below: ALTER INDEX. A SQL Server DBA myth a day: (29/30) fixing heap fragmentation. December 8, 2009. This will invoke the Tuple Mover , which will turn closed delta stores into compressed rowgroups. Rebuild or reindex ?? good question ! Analysis indexes defragmentation RATIO and decide to REORGANIZE OR REBUILD. Expand the Indexes folder. 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. Index should be reorganized when index fragmentation is between 10% to 40%. Quote from "Microsoft SQL Server 2000 Index Defragmentation Best Practices": "Fragmentation affects disk I/O. . WITH (ONLINE=ON) causes locking. Rebuilding an index can be either an online operation or an offl ine operation, depending on several factors. It's so bad on indexes that fragment that it's actually the cause of the myth of Random GUID Fragmentation. RESUMABLE = ON means you can. Regular index maintenance and statistics updates are crucial, that much is certain. ALTER FULLTEXT INDEX ON [tblname] START FULL POPULATION. Here is MSDN article on this: Reorganizing and Rebuilding Indexes. index_id = 0 -- Heap or table indexstats. Next the New Job window will open. There are two options to fix fragmentation. Rebuild or Reorganize SQL Index. DBCC DBREINDEX - use to re-index with older versions (SQL Server 2000 and earlier) sys. This means loading the table and building all nonclustered indexes before moving on to the next one. Does database on which tables reside have database owner. To solve this, I want to use the REORGANIZE operation every time. To create a new job, right click on SQL Server Agent, select New and then Job. Hi, The widely used thresholds are: Reorganize if fragmentation is between 10-30%. 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. x) and in Azure SQL Database, we recommend using ALTER. Sorted by: 1. Approved By Raja Jegan R Updated on October 18, 2023 Min Reading 4 Min Summary: MS SQL Server chooses not to use an index when it becomes fragmented. Hi all, I have SQL Server 2017 Edition and see harmful fragmentation for all tables in DB. ". This means that an index can be rebuilt without knowing the structure. First, we will start with the "Maintenance Plan Wizard":The rebuild command will defragment all those intermediate pages. Just kidding – although the evidence does point to that. ixRebuild @fillfactor int = 100, @Force bit = 0, @Schema varchar (255) = NULL, @Table varchar. This removes fragmentation, reclaims disk space by. I have been trying to gather information about rebuilding and reorganizing indexes. Select Maximum degree of parallelism, and then enter some value between 1. Right-click the index that you want to rebuild online and select Properties. indexstats. An index reorganize can be interrupted and the worst that will happen is that a single page move operation is rolled back. Large object data is data with the image, text, ntext, varchar (max), nvarchar (max), varbinary (max), or xml data type. Use the Rebuild Index Task dialog to re-create the indexes on the tables in the database with a new fill factor. 2. ALTER INDEX index_name ON table_name REORGANIZE OR. Quick explanation: An online Rebuild, rebuilds the indexes on the tempDB making it available to the queries while it is being rebuilt. dm_tran_database_transactions DMV:SQL: Procedure for rebuild and reorganize indexes like Microsoft says. Sc (Comp Sci) SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability. Here is a sample script to reorganize any index in SQL Server. Regards. A page is a small section of a database, typically an 8kb chunk. I'm just using the reorg index task that is in the maintenance plan designer GUI. If it's a rebuild, it'll have to roll back, which is single threaded, and may take a very long time. Yes. 0 to SQL Server 2016 there is no feature to rebuild index automatically. Again you most likely have some big indexes that are fragmented. Feb 21, 2022, 8:01 AM. Shrink File is. First, we will start the index reorganization in a session using the following T-SQL code. Backup Up Database (Full)4. Correct way of maintenance of SQLServer Cluster Columnstore Index. dm_db_index_physical_stats (under the Examples -> D section: Using sys. ALTER INDEX ALL ON table_name REORGANIZE OR. Let’s move on to creating the Reorganize Index task via the Maintenance Plans and then Update Statistics task. If you select one database from the "Databases" dropdown list you then get the option to. dm_db_index_physical_stats (NULL, NULL, NULL, NULL, NULL); GO. This could be done (and is in some databases) when. 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 how you can rebuild or reorganize fragmented indexes:-- Rebuild index to reduce fragmentation ALTER INDEX [YourIndexName] ON [YourTableName]. Total fragmentation is 96% page fullness 66%, avg row size is 20,. Right-click the index you want to reorganize and select Reorganize. Expand Tables. 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. 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. This task uses the ALTER INDEX. Large object data is data with the image, text, ntext, varchar (max), nvarchar (max), varbinary (max), or xml data type. From Rebuild or Reorganize: SQL Server Index Maintenance by Kendra Little: Short version: Rebuild: An index ‘rebuild’ creates a fresh, sparkling new structure for the index. When reorganizing an index, SQL Server acquires an Intent-Exclusive lock on the index B-tree. SQL Server 2019 adds resumable online index creation, and it’s pretty spiffy: 1. line is helpful to give the user some indication of what indexes it is rebuilding and how far it has progressed. Therefore you do not need to update statistics OR reorganize an index if it gets rebuilt. It doesn’t work on the intermediate pages between the root and the leaf. •DatabaseBackup: SQL Server Backup •DatabaseIntegrityCheck: SQL Server Integrity Check •IndexOptimize: SQL Server Index and Statistics Maintenance. This means that an index can be rebuilt without knowing the structure of a table or its. 1. x) 以降) および Azure SQL データベース における列ストア インデックスの場合、REORGANIZE では、次の追加のデフラグ最適化がオンラインで実行されます。 行の 10% 以上が論理的に削除されたとき、行グループから行を物理的に削除します。Also when I try to reorganize or rebuild manually, using one of the following commands: use DBNAME. I'm trying to find out how our production database indexes are getting fragmented. If we then try to reorganize this index. The performance benefit may not be noticeable for indexes that are used primarily for seek operations. The purpose is to reduce the size of database and increase the db performance. But the index is updating itself properly. This task uses the ALTER INDEX REORGANIZE statement with SQL Server databases. Mohamad Mahmoud Darwish. Last night I killed the REORG on the clustered index after almost 6 hours of execution. e check fragmentation and take an appropriate action. This caused the system to reorganize or rebuild. I don't think Windows SQL Server Maintenance has this option yet. When using columnstore indexes, the delta store may end up with multiple small row groups after inserting, updating, and. Index should be rebuilt when index fragmentation is greater than 40%. Firstly you should take into account the page_count of the index. less than 10% logical fragmentation, don’t. ALTER INDEX ALL ON table_name REBUILD OR. Also, in earlier versions the granularity of control was less refined. Update Statistics. Instead of our phone book having 1,000 pages that are 100% full, we might have 1100 pages that are only 90% full. The database is using the Simple Recovery model. Index Rebuild operation first drops and then recreates the index. And if the reorganize is a deadlock. According to Microsoft’s best practices, it is recommended to reorganize indexes if their fragmentation level is >15% and <=30% (if >30%, a rebuild should be done). I have many DBs that are currently used for insert and delete. SQL Server 2005 Index Rebuild/Reorganize. Sorted by: 5. Last night I killed the REORG on the clustered index after almost 6 hours of execution. It is used when the operation takes a. Clean Up History. ALTER FULLTEXT CATALOG [CatalogName] REBUILD. The page swapping can CRUSH you (and the tlog and data files with writes) when you have. First it’ll try an index reorganize, which is an online operation. USE AdventureWorks; GO ALTER INDEX ALL ON Production. REORGANIZES works by moving pages around, one at time. [Test] REBUILD WITH (ONLINE = ON); Additionally, I would only rebuild indexes which require it. Larger indexes have more intermediate levels and pages. A nonclustered columnstore index. Index Rebuild vs Index Reorganize. 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. The procedure uses SQL Server ALTER INDEX command, with the REORGANIZE option NULL. 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. If you want to know how far along it is, open up another instance of SSMS and connect to the server, then run a query against the sys. 1. The process uses the existing pages only and does not allocate new ones, but it does compact the index pages. We need to set these parameters for the job IndexOptimize - USER_DATABASES: @UpdateStatistics = 'ALL'. The table at issue has 111,543,114 rows. 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. Right-click Maintenance Plan and select Execute. the reorganize index also facing some problem like it is successfull once in three runs and twice it is failing. First of all you need to find the fragmentation percentage for the indexes in a database or table. The import process should be reworked to bulk-load one table at a time. Index Reorganize/ Rebuild Time. It checks the SQL Server licences, if Enterprise it will rebuild the index online else it. When investigating we found that the index reorganise for the clustered index of FooDetail takes between 90 minutes and 120 minutes. Mar 8, 2021, 2:47 PM. 7. 3) SQL Server locks acquired with SQL Server online index rebuilds. Index Rebuild : This process drops the existing Index and Recreates the index. There are a number of differences. That can be found using the STATS_DATE function. 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. . After an index reorganize, yes, for all statistics as none of them are updated by the. I would prefer to rebuild the indexes where the fragmentation percent of the indexes is greater than 30% and a Re-org of indexes where fragmentation percent is in between 9% and 30%. [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. In the Description box, briefly describe your maintenance plan. The size of one of the PK Clustered indexes is greater than 200GB, and for this one a REBUILD. Create a job to run your index reorganize ('Reorganize'). Also, running UPDATE STATISTICS gets you both index and columns stats updates. This might be a good time to stop blindly rebuilding indexes. 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. Merging the full-text index fragments can improve performance and free up disk and memory resources. This tool provides index analysis to manage index defragmentation, including rebuild and reorganize fragmented indexes . index rebuild/reorganize frequency. SQL Server Database Engine. Reorganizing should be used at lower (<30%) fragmentations but only rebuilding (which is heavier to the database) cuts the fragmentation down to 0%. Indexes play a vital role in the performance of SQL Server applications. Plan B is fine. The performance benefit may not be noticeable for indexes that are used primarily for seek operations. Script to reorganize all indexes on all tables in user databases. Ignore anything with less than 15-20 pages. Now that you learned how to create an index in SQL Server, it is time to undo it (only if you need to)! Learn how to drop an index in the next tutorial. DECLARE. MyTable REORGANIZE WITH(LOB_COMPACTION = ON). When you create or rebuild an index, by setting the SORT_IN_TEMPDB option to ON you can direct the SQL Server Database Engine to use tempdb to store the intermediate sort results that are used to build the index. If you search for index rebuilding, you will find many complex scripts on the web, but this can also be done using SQL Server Maintenance Plans which we will discuss in this article. As a general (widely accepted) rule of thumb is . Even though this is an online activity, you. This topic describes how to reorganize or rebuild a fragmented index in SQL Server 2017 by using SQL Server Management Studio or Transact-SQL. And if the reorganize is a deadlock. But your index will also use more space. Basically there’s no really easy AND resource-efficient way to do this, which is a problem with SQL Server. This opens the Toolbox and the maintenance_plan_name [Design] surface with the Subplan_1 subplan. But if you want your script to work you would have to go to index right click select properties and enable row level locking for reorganize to work this is the only optionHello, We are running SQL 2005 and I just looked over my tables indexes, and most of the indexes were very fragmented. before i answer your question is the database on simple recovery. Right-click the table on which the full-text index is defined, select Full-Text index, and on the Full-Text index context menu, select Properties. before i answer your question is the database on simple recovery. For more information, see Data Types (Transact-SQL). Rebuild the NCIs. I used the sp_who2 procedure to see which queries were waiting, and which other query they were blocked by. For maintenance i create a procedure that: -Shrink Database file (if is enabled) -Shrink Database log file. Speaking for SQL Server, I tend to choose a index size and index fragmentation level at which point I begin performing index maintenance. Rebuild Index using ApexSQL Defrag ApexSQL Defrag Overview. The Reorganize Index task also includes an option to compact large object data. Rebuild if > 30%. When you reorganize the index, you go through the existing index, cleaning up blocks for deleted records etc. T-SQL Alter Index. Select the server connection to use when performing this task. Online & Offline Index Rebuild. Index should be rebuild when index fragmentation is great than 40%. dm_db_index_physical_stats DMV). It should be: TRUNCATE; Insert ; ALTER INDEX REBUILD; It might stil be slow, but at least you get sharp indexes. Answers. .