DROP_STATISTICS
Removes statistical data on database projections previously generated by ANALYZE_STATISTICS
. When you drop this data, the Vertica optimizer creates query plans using default statistics.
Regenerating statistics can incur significant overhead.
Syntax
DROP_STATISTICS ('[[[database.]schema.]table]' [, 'category' [, '[column‑list]'] )
Parameters
[database.]schema |
Specifies a schema, by default myschema.thisDbObject If you specify a database, it must be the current database. |
table |
Table on which to drop statistics. If set to an empty string, Vertica drops statistics for all database tables and their projections. |
category |
Category of statistics to drop, one of the following:
|
column‑list | Comma-delimited list of columns in table, typically predicate columns. Vertica narrows the scope of dropped statistics to the specified columns. If you omit this parameter or supply an empty string, Vertica drops statistics on all columns. |
Privileges
Non-superuser:
- Schema: USAGE
- Table: One of INSERT, DELETE, or UPDATE
Examples
Drop all base statistics for the table store.store_sales_fact
:
=> SELECT DROP_STATISTICS('store.store_sales_fact'); DROP_STATISTICS ----------------- 0 (1 row)
Drop statistics for all table projections:
=> SELECT DROP_STATISTICS (''); DROP_STATISTICS ----------------- 0 (1 row)