RESHARD_DATABASE
Eon Mode only
Changes the number of shards in the default_namespace. You can only change the number of shards in the default_namespace if it is the only namespace in your database. If your database contains any non-default namespaces, running RESHARD_DATABASE results in an error.
RESHARD_DATABASE does not immediately affect the storage containers in communal storage. After resharding, the new shards still point to the existing containers. If you increase the number of shards in the namespace, multiple shards will point to the same storage containers. Eventually, the Tuple Mover (TM) mergeout tasks will realign the storage containers with the new shard segmentation bounds. If you want the TM to immediately realign storage containers, call DO_TM_TASK to run a 'RESHARDMERGEOUT' task.
This function requires a global catalog lock (GCLX) during runtime. The runtime depends on the size of your catalog. The function does not disrupt most queries. However, the global catalog lock might affect data loads and DDL statements.
Important
RESHARD_DATABASE might be rolled back if you call REBALANCE_SHARDS during runtime. In some cases, rollback is caused by down nodes or nodes that fail during the reshard process.Syntax
RESHARD_DATABASE(shard-count)
Arguments
shard-count- A positive integer, the number of shards in the resharded
default_namespace. For information about choosing a suitableshard-count, see Choosing the initial node and shard counts.
Privileges
Superuser
Examples
See Reshard the default namespace.