The update statistics command helps the server make the best decisions about which indexes to use when it processes a query, by providing information about the distribution of the key values in the indexes.
The update statistics commands create statistics, if there are no statistics for a particular column, or replaces existing statistics if they already exist.
The statistics are stored in the system tables systabstats and sysstatistics.
- update statistics <table> - Generates statistics for the leading column in each index on the table.
- update statistics <table> <index> - Generates statistics for all columns of the index
- update index statistics <table> - Generates statistics for all columns in all indexes on the table.
- update all statistics <table> - Generates statistics for all columns of a table.
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