CREATE CUSTOM INDEX

Creates a Storage-Attached Indexing (SAI) index. You can create multiple secondary indexes on the same database table, with each SAI index based on any column in the table. Exception: there is no need to define an SAI index based on the partition key when it's comprised of only one column; in this case, SAI issues an invalid query message.

You can also define an SAI index using one of the columns in the table's composite partition key. A composite partition key means that the partition is based on multiple columns. In this case with an SAI index, you would specify just one of the columns that comprises the composite partition key. You could define a separate SAI index that specifies another single column from the composite partition key.

Defining one or more SAI indexes based on any column in a database table (with the rules noted above) subsequently gives you the ability to run performant queries that specify the indexed column. See the SAI guide.

Synopsis

CREATE CUSTOM INDEX [ IF NOT EXISTS ] [ index_name ]
  ON [ keyspace_name.]table_name (column_name)
     [ (keys(map_name)) ] 
     [ (values(map_name)) ] 
     [ (entries(map_name)) ]
  USING 'StorageAttachedIndex' 
  [ WITH OPTIONS = { option_map } ] ;

index_name

Optional identifier for index. If no name is specified, the default is used, table_name_column_name_idx. Enclose in quotes to use special characters or to preserve capitalization.

column_name

The name of the table column on which the SAI index is being defined. SAI allows alphanumeric characters and underscores only. SAI returns InvalidRequestException if you try to define an index on a column name that contains other characters, and does not create the index.

map_name

Used with collections, identifier of the map_name specified in CREATE TABLE ... map(map_name). See SAI collection map examples with keys, values, and entries.

option_map

Define options in JSON simple format.

The following WITH OPTIONS option_map choices apply only to SAI indexes based on string columns. Not applicable with numeric column SAI indexes. See examples below.

Option	Description
case_sensitive	Ignore case in matching string values. Default: true.
normalize	When set to true, perform Unicode normalization on indexed strings. SAI supports Normalization Form C (NFC) Unicode. When set to true, SAI normalizes the different versions of a given Unicode character to a single version, retaining all the marks and symbols in the index. For example, SAI would change the character Å (U+212B) to Å (U+00C5). When implementations keep strings in a normalized form, equivalent strings have a unique binary representation. See Unicode Standard Annex #15, Unicode Normalization Forms. Default: false.

About query operators

Examples

CREATE CUSTOM INDEX lastname_sai_idx ON cycling.cyclist_semi_pro (lastname) 
USING 'StorageAttachedIndex' 
WITH OPTIONS = {'case_sensitive': false, 'normalize': true }; 

CREATE CUSTOM INDEX age_sai_idx ON cycling.cyclist_semi_pro (age) 
USING 'StorageAttachedIndex';

CREATE CUSTOM INDEX country_sai_idx ON cycling.cyclist_semi_pro (country) 
USING 'StorageAttachedIndex'
WITH OPTIONS = {'case_sensitive': false, 'normalize': true }; 

CREATE CUSTOM INDEX registration_sai_idx ON cycling.cyclist_semi_pro (registration) 
USING 'StorageAttachedIndex'; 

For sample queries that find data in cycling.cyclist_semi_pro via these sample SAI indices, see Submit CQL queries. Also refer to Examine SAI column index and query rules.

SAI collection map examples with keys, values, and entries

These examples demonstrate using collection maps with multiple types in SAI indexes. For related information, see Creating collections and Using map type.

CREATE KEYSPACE demo3 WITH replication = 
       {'class': 'SimpleStrategy', 'replication_factor': '1'};

USE demo3;

CREATE TABLE demo3.audit ( id int PRIMARY KEY , text_map map<text, text>);

CREATE CUSTOM INDEX ON demo3.audit (keys(text_map)) USING 'StorageAttachedIndex';

CREATE CUSTOM INDEX ON demo3.audit (values(text_map)) USING 'StorageAttachedIndex';

CREATE CUSTOM INDEX ON demo3.audit (entries(text_map)) USING 'StorageAttachedIndex';

INSERT INTO demo3.audit (id, text_map) values (1, {'Carlos':'Perotti', 'Marcel':'Silva'});
INSERT INTO demo3.audit (id, text_map) values (2, {'Giovani':'Pasi', 'Frances':'Giardello'});
INSERT INTO demo3.audit (id, text_map) values (3, {'Mark':'Pastore', 'Irene':'Cantona'});

SELECT * FROM demo3.audit;

 id | text_map
----+---------------------------------------------
  1 | {'Carlos': 'Perotti', 'Marcel': 'Silva'}
  2 | {'Frances': 'Giardello', 'Giovani': 'Pasi'}
  3 | {'Irene': 'Cantona', 'Mark': 'Pastore'}

(3 rows)

SELECT * FROM demo3.audit WHERE text_map['Irene'] = 'Cantona' AND text_map['Mark'] = 'Pastore';

 id | text_map
----+-----------------------------------------
  3 | {'Irene': 'Cantona', 'Mark': 'Pastore'}

(1 rows)

SELECT * FROM demo3.audit WHERE text_map CONTAINS KEY 'Giovani';

 id | text_map
----+---------------------------------------------
  2 | {'Frances': 'Giardello', 'Giovani': 'Pasi'}

(1 rows)

SELECT * FROM demo3.audit WHERE text_map CONTAINS 'Silva';

 id | text_map
----+------------------------------------------
  1 | {'Carlos': 'Perotti', 'Marcel': 'Silva'}

(1 rows)