ScyllaDB Docs ScyllaDB Enterprise CQL Reference Global Secondary Indexes

Global Secondary Indexes¶

CQL supports creating secondary indexes on tables, allowing queries on the table to use those indexes. A secondary index is identified by a name defined by:

index_name: re('[a-zA-Z_0-9]+')

CREATE INDEX¶

Creating a secondary index on a table uses the CREATE INDEX statement:

create_index_statement: CREATE INDEX [ `index_name` ]
                      :     ON `table_name` '(' `index_identifier` ')'
                      :     [ USING `string` [ WITH OPTIONS = `map_literal` ] ]
index_identifier: `column_name`
                :| ( FULL ) '(' `column_name` ')'

For instance:

CREATE INDEX userIndex ON NerdMovies (user);
CREATE INDEX ON Mutants (abilityId);

The CREATE INDEX statement is used to create a new (automatic) secondary index for a given (existing) column in a given table. A name for the index itself can be specified before the ON keyword, if desired. If data already exists for the column, it will be indexed asynchronously. After the index is created, new data for the column is indexed automatically at insertion time.

Local Secondary Index¶

Local Secondary Indexes is an enhancement of Global Secondary Indexes, which allows Scylla to optimize the use case in which the partition key of the base table is also the partition key of the index. Local Secondary Index syntax is the same as above, with extra parentheses on the partition key.

index_identifier: `column_name`
                :| ( PK ) | KEYS | VALUES | FULL ) '(' `column_name` ')'

Example:

CREATE TABLE menus (location text, name text, price float, dish_type text, PRIMARY KEY(location, name));
CREATE INDEX ON menus((location),dish_type);

DROP INDEX¶

Dropping a secondary index uses the DROP INDEX statement:

drop_index_statement: DROP INDEX [ IF EXISTS ] `index_name`

The DROP INDEX statement is used to drop an existing secondary index. The argument of the statement is the index name, which may optionally specify the keyspace of the index.

Additional Information¶

The following courses are available from Scylla University:

Apache®, Apache Cassandra®, Cassandra®, the Apache feather logo and the Apache Cassandra® Eye logo are either registered trademarks or trademarks of the Apache Software Foundation in the United States and/or other countries. No endorsement by The Apache Software Foundation is implied by the use of these marks.

Was this page helpful?