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.
|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.|