CLEAR ORPHAN DATABASES

Removes orphaned partitions. Orphaned partitions are partition databases and tables on leaf nodes that are no longer considered part of the cluster.

Syntax

CLEAR ORPHAN DATABASES;

Remarks

Caution

This command cannot be undone.

  • The master aggregator avoids dropping orphan partition databases if there is no corresponding master partition.

  • To detect orphan partitions, run SHOW CLUSTER STATUS and check for partitions with the role of Orphan.

  • Before running CLEAR ORPHAN DATABASES, run: EXPLAIN CLEAR ORPHAN DATABASES; to see which partitions will be dropped.

  • Orphan tables are tables that don't exist in metadata but do exist on some partition databases. For example, if a table is dropped on the master in asynchronous replication and its node fails before it can succeed then the table could become an orphan table.

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