What is reindex in SQL Server?

How do I reindex a SQL database?

Rebuild an index1In Object Explorer, Expand the database that contains the table on which you want to reorganize an index.2Expand the Tables folder.3Expand the table on which you want to reorganize an index.4Expand the Indexes folder.5Right-click the index you want to reorganize and select Rebuild.Reorganize and Rebuild Indexes in the Database - BeyondTrust

When should I reindex SQL Server?

Microsoft recommends fixing index fragmentation issues by rebuilding the index if the fragmentation percentage of the index exceeds 30%, where it recommends fixing the index fragmentation issue by reorganizing the index if the index fragmentation percentage exceeds 5% and less than 30%.

What does Reindexing a database mean?

Description. REINDEX rebuilds an index using the data stored in the index's table, replacing the old copy of the index. There are several scenarios in which to use REINDEX: An index has become corrupted, and no longer contains valid data.

What are Securables in SQL Server?

Securables are the resources to which the SQL Server Database Engine authorization system regulates access. For example, a table is a securable. Some securables can be contained within others, creating nested hierarchies called "scopes" that can themselves be secured.