摘要:
Various embodiments of a method, apparatus and article of manufacture of managing statistics in a database management system are provided. A volatility of at least one of statistic is determined. One or more statistics collection tasks are generated based on, at least in part, the volatility.
摘要:
In various embodiments, a method, apparatus, and article of manufacture collect statistics in a database management system. A workload comprising a plurality of database queries is received. Query statistics for the database queries are identified. The query statistics for the database queries are consolidated to provide consolidated statistics. One or more statistics collection requests are generated based on the consolidated statistics.
摘要:
In various embodiments, a method, apparatus, and article of manufacture collect statistics in a database management system. A workload comprising a plurality of database queries is received. Query statistics for the database queries are identified. The query statistics for the database queries are consolidated to provide consolidated statistics. One or more statistics collection requests are generated based on the consolidated statistics.
摘要:
Disclosed is a technique for maintaining statistics. A query is received. Column group generation is performed to form one or more column groups. Column group refinement is performed based on statistics data generated for a previously received query. A statistics check is automatically performed. A statistics collection command is generated to obtain statistics.
摘要:
A method, apparatus, and article of manufacture for optimizing a query in a computer system, wherein the query is performed by the computer system to retrieve data from a database stored on the computer system. The optimization is performed by identifying a correlated subquery in the query that qualifies for transformation, transitively closing a local filtering predicate within the identified correlated subquery that is on a same column as a correlation join predicate within the identified correlated subquery, and pulling out or bubbling up the transitively closed predicate from the correlated subquery to a parent query block of the query.