The log_alert_* tables store pg_log errors and warnings.

See Alert Log Processing and Log Rotation for information about configuring the system logger for gpperfmon.

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

• log_alert_now is an external table whose data is stored in .csv files in the $MASTER_DATA_DIRECTORY/gpperfmon/logs directory. Current pg_log errors and warnings data are available in log_alert_now during the period between data collection from the gpperfmon agents and automatic commitment to the log_alert_history table.
• log_alert_tail is an external table with data stored in $MASTER_DATA_DIRECTORY/gpperfmon/logs/alert_log_stage. This is a transitional table for data that has been cleared from log_alert_now but has not yet been committed to log_alert_history. The table includes records from all alert logs except the most recent. It typically contains only a few minutes' worth of data.
• log_alert_history is a regular table that stores historical database-wide errors and warnings data. It is pre-partitioned into monthly partitions. Partitions are automatically added in two month increments as needed.