The gpperfmon Database - system_* - 《Greenplum Database v6.23 Documentation》

The system_* tables store system utilization metrics. There are three system tables, all having the same columns:

system_now is an external table whose data files are stored in $MASTER_DATA_DIRECTORY/gpperfmon/data. Current system utilization data is stored in system_now during the period between data collection from the gpperfmon agents and automatic commitment to the system_history table.
system_tail is an external table whose data files are stored in $MASTER_DATA_DIRECTORY/gpperfmon/data. This is a transitional table for system utilization data that has been cleared from system_now but has not yet been committed to system_history. It typically only contains a few minutes worth of data.
system_history is a regular table that stores historical system utilization metrics. It is pre-partitioned into monthly partitions. Partitions are automatically added in two month increments as needed.

Column	Type	Description
`ctime`	timestamp	Time this row was created.
`hostname`	varchar(64)	Segment or master hostname associated with these system metrics.
`mem_total`	bigint	Total system memory in Bytes for this host.
`mem_used`	bigint	Used system memory in Bytes for this host.
`mem_actual_used`	bigint	Used actual memory in Bytes for this host (not including the memory reserved for cache and buffers).
`mem_actual_free`	bigint	Free actual memory in Bytes for this host (not including the memory reserved for cache and buffers).
`swap_total`	bigint	Total swap space in Bytes for this host.
`swap_used`	bigint	Used swap space in Bytes for this host.
`swap_page_in`	bigint	Number of swap pages in.
`swap_page_out`	bigint	Number of swap pages out.
`cpu_user`	float	CPU usage by the Greenplum system user.
`cpu_sys`	float	CPU usage for this host.
`cpu_idle`	float	Idle CPU capacity at metric collection time.
`load0`	float	CPU load average for the prior one-minute period.
`load1`	float	CPU load average for the prior five-minute period.
`load2`	float	CPU load average for the prior fifteen-minute period.
`quantum`	int	Interval between metric collection for this metric entry.
`disk_ro_rate`	bigint	Disk read operations per second.
`disk_wo_rate`	bigint	Disk write operations per second.
`disk_rb_rate`	bigint	Bytes per second for disk read operations.
`disk_wb_rate`	bigint	Bytes per second for disk write operations.
`net_rp_rate`	bigint	Packets per second on the system network for read operations.
`net_wp_rate`	bigint	Packets per second on the system network for write operations.
`net_rb_rate`	bigint	Bytes per second on the system network for read operations.
`net_wb_rate`	bigint	Bytes per second on the system network for write operations.

Parent topic: The gpperfmon Database