System Operation

MogDB 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 MogDB 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. 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.