RESHARD_DATABASE
Eon Mode only
Changes the number of shards in a database. This function requires a global catalog lock (GCLX) during runtime. The runtime depends on the size of your catalog.
RESHARD_DATABASE does not immediately affect the storage containers in communal storage. After re-sharding, the new shards still point to the existing containers. If you increase the number of shards in your database, 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 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 re-shard process.Syntax
RESHARD_DATABASE(shard-count)
Arguments
shard-count- A positive integer, the number of shards in the re-sharded database. For information about choosing a suitable
shard-count, see Choosing the Number of Shards and the Initial Node Count.
Privileges
Superuser
Examples
See Change the number of shards in the database.