PAUSE CLUSTER

PAUSE CLUSTER — pause the Postgres-XL cluster

Synopsis

PAUSE CLUSTER

Description

PAUSE CLUSTER is a SQL command specific to Postgres-XL that pauses cluster operation.

Pause blocks any new transactions from starting and waits until existing transactions complete, then returns. Existing sessions are still connected to Coordinators, it is just that any new statements will be held up and not be executed.

The session that paused the cluster can perform tasks exclusively on the cluster. This is useful for maintenance tasks to resolve a problem, restart a Datanode, manually failover a Datanode, etc. Applications will not receive error messages unless they themselves timeout, statement execution will just be briefly suspended.

Once the DBA has completed whatever tasks were needed, the command UNPAUSE CLUSTER can be used.

Compatibility

PAUSE CLUSTER does not conform to the SQL standards, it is a Postgres-XL specific command.