Optimized collection of just-in-time statistics for database query optimization

摘要

A system and method are provided for updating database statistics for use in generating query execution plans. A first query for a database is received, for example by a compiler, and the compiler accesses statistics associated with the first query for optimizing a query execution plan for the first query. The statistics may be accessed from a first cache. If the statistics retrieved from the first cache are determined to be stale, the system obtains updated statistics and may store them in a temporary cache. The stale statistics in the first cache are marked as invalid. Existing queries using the first cache may continue to use the first cache, while new queries may be provided with updated statistics.