[jira] [Updated] (CASSANDRA-8473) Secondary index support for key-value pairs in CQL3 maps

["Samuel Klock (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/CASSANDRA-8473?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Samuel Klock updated CASSANDRA-8473:
------------------------------------
    Attachment: cassandra-2.1-8473.txt

Attaching proposed patch.

> Secondary index support for key-value pairs in CQL3 maps
> --------------------------------------------------------
>
>                 Key: CASSANDRA-8473
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-8473
>             Project: Cassandra
>          Issue Type: Improvement
>            Reporter: Samuel Klock
>         Attachments: cassandra-2.1-8473.txt
>
>
> CASSANDRA-4511 and CASSANDRA-6383 made substantial progress on secondary indexes on CQL3 maps, but support for a natural use case is still missing: queries to find rows with map columns containing some key-value pair.  For example (from a comment on CASSANDRA-4511):
> {code:sql}
> SELECT * FROM main.users WHERE notify['email'] = true;
> {code}
> Cassandra should add support for this kind of index.  One option is to expose a CQL interface like the following:
> * Creating an index:
> {code:sql}
> cqlsh:mykeyspace> CREATE TABLE mytable (key TEXT PRIMARY KEY, value MAP<TEXT, TEXT>);
> cqlsh:mykeyspace> CREATE INDEX ON mytable(ENTRIES(value));
> {code}
> * Querying the index:
> {code:sql}
> cqlsh:mykeyspace> INSERT INTO mytable (key, value) VALUES ('foo', {'a': '1', 'b': '2', 'c': '3'});
> cqlsh:mykeyspace> INSERT INTO mytable (key, value) VALUES ('bar', {'a': '1', 'b': '4'});
> cqlsh:mykeyspace> INSERT INTO mytable (key, value) VALUES ('baz', {'b': '4', 'c': '3'});
> cqlsh:mykeyspace> SELECT * FROM mytable WHERE value['a'] = '1';
>  key | value
> -----+--------------------------------
>  bar |           {'a': '1', 'b': '4'}
>  foo | {'a': '1', 'b': '2', 'c': '3'}
> (2 rows)
> cqlsh:mykeyspace> SELECT * FROM mytable WHERE value['a'] = '1' AND value['b'] = '2' ALLOW FILTERING;
>  key | value
> -----+--------------------------------
>  foo | {'a': '1', 'b': '2', 'c': '3'}
> (1 rows)
> cqlsh:mykeyspace> SELECT * FROM mytable WHERE value['b'] = '2' ALLOW FILTERING;
>  key | value                         
> -----+--------------------------------
>  foo | {'a': '1', 'b': '2', 'c': '3'}
> (1 rows)                             
> cqlsh:mykeyspace> SELECT * FROM mytable WHERE value['b'] = '4';
>  key | value
> -----+----------------------
>  bar | {'a': '1', 'b': '4'}
>  baz | {'b': '4', 'c': '3'}
> (2 rows)
> {code}
> A patch against the Cassandra-2.1 branch that implements this interface will be attached to this issue shortly.



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