BATCH¶

Multiple INSERT, UPDATE and DELETE can be executed in a single statement by grouping them through a BATCH statement:

batch_statement: BEGIN [ UNLOGGED | COUNTER ] BATCH
               : [ USING `update_parameter` ( AND `update_parameter` )* ]
               : `modification_statement` ( ';' `modification_statement` )*
               : APPLY BATCH
modification_statement: `insert_statement` | `update_statement` | `delete_statement`

For instance:

BEGIN BATCH
   INSERT INTO users (userid, password, name) VALUES ('user2', 'ch@ngem3b', 'second user');
   UPDATE users SET password = 'ps22dhds' WHERE userid = 'user3';
   INSERT INTO users (userid, password) VALUES ('user4', 'ch@ngem3c');
   DELETE name FROM users WHERE userid = 'user1';
APPLY BATCH;

The BATCH statement group multiple modification statements (insertions/updates and deletions) into a single statement. It serves several purposes:

• It saves network round-trips between the client and the server (and sometimes between the server coordinator and the replicas) when batching multiple updates.

• All updates in a BATCH belonging to a given partition key are performed atomically.

• By default, all operations in the batch are performed as logged, to ensure all mutations eventually complete (or none will). See the notes on UNLOGGED batches for more details.

Note that:

• BATCH statements may only contain UPDATE, INSERT and DELETE statements (not other batches, for instance).

• Batches are not a full analogue for SQL transactions.

• If a timestamp is not specified for each operation, then all operations will be applied with the same timestamp (either one generated automatically, or the timestamp provided at the batch level). Due to Scylla’s conflict resolution procedure in the case of timestamp ties, operations may be applied in an order that is different from the order they are listed in the BATCH statement. To force a particular operation ordering, you must specify per-operation timestamps.

• A LOGGED batch to a single partition will be converted to an UNLOGGED batch as an optimization.

BATCH supports the TIMESTAMP option with the same semantics as the TIMESTAMP parameter in UPDATE statement. For more information on the update_parameter refer to the UPDATE section.