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https://issues.apache.org/jira/browse/CASSANDRA-11223?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16072265#comment-16072265
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Benjamin Lerer commented on CASSANDRA-11223:
--------------------------------------------
I pushed a patch for
[2.2|https://github.com/apache/cassandra/compare/cassandra-2.2...blerer:11223-2.2]
and
[3.0|https://github.com/apache/cassandra/compare/cassandra-3.0...blerer:11223-3.0].
I ran the tests on our internal CI and the results look good. The DTests
failures appear to be unrelated to the patches.
The {{3.0}} patch solve the problem by not counting partitions with only static
data when the there are some restrictions on the clustering or regular columns.
The {{2.2}} patch does not count partitions with only static data when the
there are some restrictions on the clustering column. In {{2.2}}, partitions
with only static data are never returned for index queries due to that checking
restrictions on regular columns was not needed.
[~Stefania] Could you have a first look before I create the patch for {{3.11}}
and {{trunk}}?
> Queries with LIMIT filtering on clustering columns can return less rows than
> expected
> -------------------------------------------------------------------------------------
>
> Key: CASSANDRA-11223
> URL: https://issues.apache.org/jira/browse/CASSANDRA-11223
> Project: Cassandra
> Issue Type: Bug
> Components: Local Write-Read Paths
> Reporter: Benjamin Lerer
> Assignee: Benjamin Lerer
>
> A query like {{SELECT * FROM %s WHERE b = 1 LIMIT 2 ALLOW FILTERING}} can
> return less row than expected if the table has some static columns and some
> of the partition have no rows matching b = 1.
> The problem can be reproduced with the following unit test:
> {code}
> public void testFilteringOnClusteringColumnsWithLimitAndStaticColumns()
> throws Throwable
> {
> createTable("CREATE TABLE %s (a int, b int, s int static, c int,
> primary key (a, b))");
> for (int i = 0; i < 3; i++)
> {
> execute("INSERT INTO %s (a, s) VALUES (?, ?)", i, i);
> for (int j = 0; j < 3; j++)
> if (!(i == 0 && j == 1))
> execute("INSERT INTO %s (a, b, c) VALUES (?, ?, ?)",
> i, j, i + j);
> }
> assertRows(execute("SELECT * FROM %s"),
> row(1, 0, 1, 1),
> row(1, 1, 1, 2),
> row(1, 2, 1, 3),
> row(0, 0, 0, 0),
> row(0, 2, 0, 2),
> row(2, 0, 2, 2),
> row(2, 1, 2, 3),
> row(2, 2, 2, 4));
> assertRows(execute("SELECT * FROM %s WHERE b = 1 ALLOW FILTERING"),
> row(1, 1, 1, 2),
> row(2, 1, 2, 3));
> assertRows(execute("SELECT * FROM %s WHERE b = 1 LIMIT 2 ALLOW
> FILTERING"),
> row(1, 1, 1, 2),
> row(2, 1, 2, 3)); // <-------- FAIL It returns only one
> row because the static row of partition 0 is counted and filtered out in
> SELECT statement
> }
> {code}
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