The database_* tables store query workload information for a Greenplum Database instance. There are three database tables, all having the same columns:

  • database_now is an external table whose data files are stored in$MASTER_DATA_DIRECTORY/gpperfmon/data. Current query workload data is stored in database_now during the period between data collection from the Command Center agents and automatic commitment to the database_history table.
  • database_tail is an external table whose data files are stored in $MASTER_DATA_DIRECTORY/gpperfmon/data. This is a transitional table for query workload data that has been cleared from database_now but has not yet been committed to database_history. It typically only contains a few minutes worth of data.
  • database_history is a regular table that stores historical database-wide query workload data. It is pre-partitioned into monthly partitions. Partitions are automatically added in two month increments as needed. Administrators must drop old partitions for the months that are no longer needed.
Column Type Description
ctime timestamp Time this row was created.
queries_total int The total number of queries in Greenplum Database at data collection time.
queries_running int The number of active queries running at data collection time.
queries_queued int The number of queries waiting in a resource queue at data collection time.