Collecting Statistics on Partitioned Tables

For partitioned tables, you can collect partition-level statistics, which can be queried in the pg_partition and pg_statistic system catalogs and in the pg_stats and pg_ext_stats views.

Partition-level statistics apply to the scenario where the scan range is reduced to a single partition after static pruning is performed on a partitioned table. The following statistics can be collected: number of pages and tuples at the partition level, single-column statistics, multi-column statistics, and expression index statistics.

You can collect statistics on partitioned tables in either of the following ways:

• Collect statistics in cascading mode.
• Collect statistics on a specified partition.

• Collecting Statistics in Cascading Mode
  
• Collecting Partition-Level Statistics