## 17.8. Run-Time Statistics

### 17.8.1. Statistics Monitoring

`log_statement_stats` (`boolean`)
`log_parser_stats` (`boolean`)
`log_planner_stats` (`boolean`)
`log_executor_stats` (`boolean`)

  For each query, write performance statistics of the respective module to the server log. This is a crude profiling instrument. `log_statement_stats` reports total statement statistics, while the others report per-module statistics. `log_statement_stats` cannot be enabled together with any of the per-module options. All of these options are disabled by default. Only superusers can change these settings.

### 17.8.2. Query and Index Statistics Collector

`stats_start_collector` (`boolean`)

  Controls whether the server should start the statistics-collection subprocess. This is on by default, but may be turned off if you know you have no interest in collecting statistics. This option can only be set at server start.

`stats_command_string` (`boolean`)

  Enables the collection of statistics on the currently executing command of each session, along with the time at which that command began execution. This option is off by default. Note that even when enabled, this information is not visible to all users, only to superusers and the user owning the session being reported on; so it should not represent a security risk. This data can be accessed via the `pg_stat_activity` system view; refer to Chapter 24, Monitoring Database Activity for more information.

`stats_block_level` (`boolean`)

  Enables the collection of block-level statistics on database activity. This option is disabled by default. If this option is enabled, the data that is produced can be accessed via the `pg_stat` and `pg_statio` family of system views; refer to Chapter 24, Monitoring Database Activity for more information.

`stats_row_level` (`boolean`)

  Enables the collection of row-level statistics on database activity. This option is disabled by default. If this option is enabled, the data that is produced can be accessed via the `pg_stat` and `pg_statio` family of system views; refer to Chapter 24, Monitoring Database Activity for more information.

`stats_reset_on_server_start` (`boolean`)

  If on, collected statistics are zeroed out whenever the server is restarted. If off, statistics are accumulated across server restarts. The default is `off`. This option can only be set at server start.