Question: How Can I Rebuild My Index Online?

How does online Rebuild Index work in SQL Server?

The ONLINE option allows concurrent user access to the underlying table or clustered index data and any associated nonclustered indexes during these index operations.

For example, while a clustered index is being rebuilt by one user, that user and others can continue to update and query the underlying data..

Why do we rebuild indexes?

When and how often should you Rebuild Indexes? The performance of your indexes, and therefore your database queries, will degrade as you indexes become fragmented. The Rebuild Index task does a very good job of rebuilding indexes to remove logical fragmentation and empty space, and updating statistics.

Should I rebuild or reorganize indexes?

An index rebuild will always build a new index, even if there’s no fragmentation. … This means that for a lightly fragmented index (e.g. less than 30% fragmentation), it’s generally faster to reorganize the index, but for a more heavily fragmented index, it’s generally faster to just rebuild the index.

Does rebuilding clustered index rebuild nonclustered?

It’ll have absolutely no effect on the nonclustered indexes. Nonclustered indexes use the clustered index key as a ‘pointer’ and that doesn’t change in a rebuild. … A non-clustered index is not rebuilt if a clustered index is rebuilt, on SQL Server 2005 and higher.

What is the difference between index rebuild and index reorganize?

Index Rebuild : This process drops the existing Index and Recreates the index. Index Reorganize : This process physically reorganizes the leaf nodes of the index. … Index should be reorganized when index fragmentation is between 10% to 40%. Index rebuilding process uses more CPU and it locks the database resources.

Does rebuilding indexes improve performance?

The index rebuild should leave you with indexes that have a standard amount of fragmentation, as determined by the Fill Factor. As you start to do inserts, index performance will actually improve for a time as the free-space pages are used, and then start to deteriorate as index fragmentation begins.

Can you rebuild a clustered index?

To efficiently rebuild a clustered index, the CREATE INDEX command provides the DROP_EXISTING option. … When a table’s clustered index is dropped using a DROP command and then re-added using a CREATE command, each non-clustered index on the table can be re-created twice.

How do I speed up index rebuild in SQL Server?

By changing the number of processors SQL Server can use in parallel, in other words the maximum degree of parallelism (MAXDOP), we can improve index rebuild performance. This option is by default set to zero instance-wide on SQL Server, it does not mean use zero processors.

How do you rebuild indexes?

Open up the “Indexing Options” window by hitting Start and typing “Indexing Options.” In the “Indexing Options” window, click the “Advanced” button. In the “Advanced Options” window, click the “Rebuild” button. After that, it’s just a matter of waiting while Windows rebuilds the index from scratch.

When should you rebuild indexes?

You should rebuild indexes when they become highly fragmented by special events. For example, you perform a large, bulk load of data into an indexed table.

How do you reindex a database?

Rebuild an IndexRight click on an index and go to Properties.Select Fragmentation from the Select a page window. … Click out of that window and right click on your index again. … Click Okay and the window and your Index will be rebuilt. … Rebuild All Indexes in a Table. … Then click okay.Or you can use the follow SQL Code.More items…•

How often should I rebuild indexes SQL Server?

4 Answers. There’s a general consensus that you should reorganize (“defragment”) your indices as soon as index fragmentation reaches more than 5 (sometimes 10%), and you should rebuild them completely when it goes beyond 30% (at least that’s the numbers I’ve heard advocated in a lot of places).