System Operation ​

openGauss text runs SQL statements to perform different system operations, such as setting variables, displaying the execution plan, and collecting garbage data.

Setting Variables ​

For details about how to set various parameters for a session or transaction, see SET.

Displaying the Execution Plan ​

For details about how to display the execution plan that openGauss makes for SQL statements, see EXPLAIN.

Specifying a Checkpoint in Transaction Logs ​

By default, WALs periodically specify checkpoints in a transaction log. CHECKPOINT forces an immediate checkpoint when the related command is issued, without waiting for a regular checkpoint scheduled by the system. For details, see CHECKPOINT.

Collecting Unnecessary Data ​

For details about how to collect garbage data and analyze a database as required, see VACUUM.

Collecting Statistics ​

For details about how to collect statistics on tables in databases, see ANALYZE | ANALYSE.

Setting the Constraint Check Mode for the Current Transaction ​

For details about how to set the constraint check mode for the current transaction, see SET CONSTRAINTS.

Shutting Down The Current Database Node ​

For details about shutting down the current database node, see SHUTDOWN.