pg_buffercache
The pg_buffercache module provides five views for obtaining cluster-wide shared buffer metrics:
gp_buffercachegp_buffercache_summarygp_buffercache_usage_countsgp_buffercache_summary_aggregatedgp_buffercache_usage_counts_aggregated
The gp_buffercache view is a cluster-wide view that displays the pg_buffercache information from the coordinator and every primary segment for each buffer in the shared cache.
The gp_buffercache_summary view is a cluster-wide view that displays the pg_buffercache_summary information from the coordinator and each primary segment, summarized as one row per segment. Similar and more detailed information is provided by gp_buffercache, but gp_buffercache_summary is significantly better performance-wise.
The gp_buffercache_usage_counts view is a cluster-wide view that displays the pg_puffercache_usage_counts information from the coordinator and each primary segment returning summarized states of all shared buffers, aggregated over the possible usage count values. Similar and more detailed information is provided by gp_buffercache, but gp_buffercache_usage_counts is significantly better performance-wise.
The gp_buffercache_summary_aggregated view returns a single row with the aggregated output of gp_buffercache_summary.
The gp_buffercache_usage_counts_aggregated view returns a single row with the aggregated output of gp_buffercache_usage_counts.
Installing and Registering the Module
The pg_buffercache module is installed when you install VMware Greenplum. Before you can use any of the functions defined in the module, you must register the pg_buffercache extension in each database in which you want to use the functions:
CREATE EXTENSION pg_buffercache;
Refer to Installing Additional Supplied Modules for more information.
Module Documentation
See pg_buffercache in the PostgreSQL documentation for detailed information about the individual functions in this module.
