[CASSANDRA-6875] CQL3: select multiple CQL rows in a single partition using IN

• Type: Bug
• Status: Resolved
• Priority: Low
• Resolution: Fixed
• Fix Version/s: 2.0.9, 2.1 rc1
• Component/s: Legacy/CQL
• Severity: Low
• Assignee: Tom Hobbs
• Reporter: Nicolas Favre-Felix

Authors

Tom Hobbs

Reviewers

Sylvain Lebresne

• Created: 17/Mar/14 17:25
• Updated: 16/Apr/19 09:31
• Resolved: 29/May/14 18:29

Description

In the spirit of CASSANDRA-4851 and to bring CQL to parity with Thrift, it is important to support reading several distinct CQL rows from a given partition using a distinct set of "coordinates" for these rows within the partition.

CASSANDRA-4851 introduced a range scan over the multi-dimensional space of clustering keys. We also need to support a "multi-get" of CQL rows, potentially using the "IN" keyword to define a set of clustering keys to fetch at once.

(reusing the same example:)

Consider the following table:

CREATE TABLE test (
  k int,
  c1 int,
  c2 int,
  PRIMARY KEY (k, c1, c2)
);

with the following data:

 k | c1 | c2
---+----+----
 0 |  0 |  0
 0 |  0 |  1
 0 |  1 |  0
 0 |  1 |  1

We can fetch a single row or a range of rows, but not a set of them:

> SELECT * FROM test WHERE k = 0 AND (c1, c2) IN ((0, 0), (1,1)) ;
Bad Request: line 1:54 missing EOF at ','

Supporting this syntax would return:

 k | c1 | c2
---+----+----
 0 |  0 |  0
 0 |  1 |  1

Being able to fetch these two CQL rows in a single read is important to maintain partition-level isolation.

Issue Links

• is duplicated by: CASSANDRA-7854 Unable to select partition keys directly using IN keyword (no replacement for multi row multiget in thrift)