[CASSANDRA-7855] Genralize use of IN for compound partition keys

• Type: Improvement
• Status: Resolved
• Priority: Low
• Resolution: Fixed
• Fix Version/s: 2.2.0 beta 1
• Component/s: Legacy/CQL
• Labels: cql docs
• Assignee: Benjamin Lerer
• Reporter: Sylvain Lebresne

Authors

Benjamin Lerer

Reviewers

Sam Tunnicliffe

• Created: 01/Sep/14 09:36
• Updated: 16/Apr/19 09:31
• Resolved: 30/Jan/15 18:06

Description

When you have a compount partition key, we currently only support to have a IN on the last column of that partition key. So given:

CREATE TABLE foo (
    k1 int,
    k2 int,
    v int,
    PRIMARY KEY ((k1, k2))
)

we allow

SELECT * FROM foo WHERE k1 = 0 AND k2 IN (1, 2)

but not

SELECT * FROM foo WHERE k1 IN (0, 1) AND k2 IN (1, 2)

There is no particular reason for us not supporting the later (to the best of my knowledge) since it's reasonably straighforward, so we should fix it.

I'll note that using IN on a partition key is not necessarily a better idea than parallelizing queries server client side so this syntax, when introduced, should probably be used sparingly, but given we do support IN on partition keys, I see no reason not to extend it to compound PK properly.