tcp_stats_*

The tcp_stats_* tables store statistical metrics about TCP communications for a Greenplum Database instance.

These tables are in place for future use and are not currently populated.

There are three system tables, all having the same columns:

tcp_stats_now is an external table whose data files are stored in $MASTER_DATA_DIRECTORY/gpperfmon/data.
tcp_stats_tail is an external table whose data files are stored in $MASTER_DATA_DIRECTORY/gpperfmon/data. This is a transitional table for TCP statistical data that has been cleared from tcp_stats_now but has not yet been committed to tcp_stats_history. It typically only contains a few minutes worth of data.
tcp_stats_history is a regular table that stores historical TCP statistical 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
`segments_received`	bigint	Number of TCP segments received.
`segments_sent`	bigint	Number of TCP segments sent.
`segments_retransmitted`	bigint	Number of TCP segments retransmitted.
`active_connections`	int	Number of active TCP connections.
`passive_connections`	int	Number of passive TCP connections.
`failed_connection_attempts`	int	Number of failed TCP connection attempts.
`connections_established`	int	Number of TCP connections established.
`connection_resets_received`	int	Number of TCP connection resets received.
`connection_resets_sent`	int	Number of TCP connection resets sent.