[jira] [Commented] (CASSANDRA-4579) CQL queries using LIMIT sometimes missing results
[ https://issues.apache.org/jira/browse/CASSANDRA-4579?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13457346#comment-13457346 ] Pavel Yaskevich commented on CASSANDRA-4579: +1 CQL queries using LIMIT sometimes missing results - Key: CASSANDRA-4579 URL: https://issues.apache.org/jira/browse/CASSANDRA-4579 Project: Cassandra Issue Type: Bug Components: Core Affects Versions: 1.2.0 beta 1 Reporter: paul cannon Assignee: Sylvain Lebresne Labels: cql, cql3 Fix For: 1.2.0 beta 1 Attachments: 0001-Add-all-columns-from-a-prefix-group-before-stopping.txt, 0002-Fix-LIMIT-for-NamesQueryFilter.txt In certain conditions, CQL queries using LIMIT clauses are not being given all of the expected results (whether unset column values or missing rows). Here are the condition sets I've been able to identify: First mode: all rows are returned, but in the last row of results, all columns which are not part of the primary key receive no values, except for the first non-primary-key column. Conditions: * Table has a multi-component primary key * Table has more than one column which is not a component of the primary key * The number of results which would be returned by a query is equal to or more than the specified LIMIT Second mode: result has fewer rows than it should, lower than both the LIMIT and the actual number of matching rows. Conditions: * Table has a single-column primary key * Table has more than one column which is not a component of the primary key * The number of results which would be returned by a query is equal to or more than the specified LIMIT It would make sense to me that this would have started with CASSANDRA-4329, but bisecting indicates that this behavior started with commit 91bdf7fb4220b27e9566c6673bf5dbd14153017c, implementing CASSANDRA-3647. Test case for the first failure mode: {noformat} DROP KEYSPACE test; CREATE KEYSPACE test WITH strategy_class = 'SimpleStrategy' AND strategy_options:replication_factor = 1; USE test; CREATE TABLE testcf ( a int, b int, c int, d int, e int, PRIMARY KEY (a, b) ); INSERT INTO testcf (a, b, c, d, e) VALUES (1, 11, 111, , 1); INSERT INTO testcf (a, b, c, d, e) VALUES (2, 22, 222, , 2); INSERT INTO testcf (a, b, c, d, e) VALUES (3, 33, 333, , 3); INSERT INTO testcf (a, b, c, d, e) VALUES (4, 44, 444, , 4); SELECT * FROM testcf; SELECT * FROM testcf LIMIT 1; -- columns d and e in result row are null SELECT * FROM testcf LIMIT 2; -- columns d and e in last result row are null SELECT * FROM testcf LIMIT 3; -- columns d and e in last result row are null SELECT * FROM testcf LIMIT 4; -- columns d and e in last result row are null SELECT * FROM testcf LIMIT 5; -- results are correct (4 rows returned) {noformat} Test case for the second failure mode: {noformat} CREATE KEYSPACE test WITH strategy_class = 'SimpleStrategy' AND strategy_options:replication_factor = 1; USE test; CREATE TABLE testcf ( a int primary key, b int, c int, ); INSERT INTO testcf (a, b, c) VALUES (1, 11, 111); INSERT INTO testcf (a, b, c) VALUES (2, 22, 222); INSERT INTO testcf (a, b, c) VALUES (3, 33, 333); INSERT INTO testcf (a, b, c) VALUES (4, 44, 444); SELECT * FROM testcf; SELECT * FROM testcf LIMIT 1; -- gives 1 row SELECT * FROM testcf LIMIT 2; -- gives 1 row SELECT * FROM testcf LIMIT 3; -- gives 2 rows SELECT * FROM testcf LIMIT 4; -- gives 2 rows SELECT * FROM testcf LIMIT 5; -- gives 3 rows {noformat} -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (CASSANDRA-4579) CQL queries using LIMIT sometimes missing results
[ https://issues.apache.org/jira/browse/CASSANDRA-4579?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13442709#comment-13442709 ] paul cannon commented on CASSANDRA-4579: Thanks to Christoph Hack for identifying the problem. CQL queries using LIMIT sometimes missing results - Key: CASSANDRA-4579 URL: https://issues.apache.org/jira/browse/CASSANDRA-4579 Project: Cassandra Issue Type: Bug Components: Core Affects Versions: 1.2.0 Reporter: paul cannon Labels: cql, cql3 Fix For: 1.2.0 In certain conditions, CQL queries using LIMIT clauses are not being given all of the expected results (whether unset column values or missing rows). Here are the condition sets I've been able to identify: First mode: all rows are returned, but in the last row of results, all columns which are not part of the primary key receive no values, except for the first non-primary-key column. Conditions: * Table has a multi-component primary key * Table has more than one column which is not a component of the primary key * The number of results which would be returned by a query is equal to or more than the specified LIMIT Second mode: result has fewer rows than it should, lower than both the LIMIT and the actual number of matching rows. Conditions: * Table has a single-column primary key * Table has more than one column which is not a component of the primary key * The number of results which would be returned by a query is equal to or more than the specified LIMIT It would make sense to me that this would have started with CASSANDRA-4329, but bisecting indicates that this behavior started with commit 91bdf7fb4220b27e9566c6673bf5dbd14153017c, implementing CASSANDRA-3647. Test case for the first failure mode: {noformat} DROP KEYSPACE test; CREATE KEYSPACE test WITH strategy_class = 'SimpleStrategy' AND strategy_options:replication_factor = 1; USE test; CREATE TABLE testcf ( a int, b int, c int, d int, e int, PRIMARY KEY (a, b) ); INSERT INTO testcf (a, b, c, d, e) VALUES (1, 11, 111, , 1); INSERT INTO testcf (a, b, c, d, e) VALUES (2, 22, 222, , 2); INSERT INTO testcf (a, b, c, d, e) VALUES (3, 33, 333, , 3); INSERT INTO testcf (a, b, c, d, e) VALUES (4, 44, 444, , 4); SELECT * FROM testcf; SELECT * FROM testcf LIMIT 1; -- columns d and e in result row are null SELECT * FROM testcf LIMIT 2; -- columns d and e in last result row are null SELECT * FROM testcf LIMIT 3; -- columns d and e in last result row are null SELECT * FROM testcf LIMIT 4; -- columns d and e in last result row are null SELECT * FROM testcf LIMIT 5; -- results are correct (4 rows returned) {noformat} Test case for the second failure mode: {noformat} CREATE KEYSPACE test WITH strategy_class = 'SimpleStrategy' AND strategy_options:replication_factor = 1; USE test; CREATE TABLE testcf ( a int primary key, b int, c int, ); INSERT INTO testcf (a, b, c) VALUES (1, 11, 111); INSERT INTO testcf (a, b, c) VALUES (2, 22, 222); INSERT INTO testcf (a, b, c) VALUES (3, 33, 333); INSERT INTO testcf (a, b, c) VALUES (4, 44, 444); SELECT * FROM testcf; SELECT * FROM testcf LIMIT 1; -- gives 1 row SELECT * FROM testcf LIMIT 2; -- gives 1 row SELECT * FROM testcf LIMIT 3; -- gives 2 rows SELECT * FROM testcf LIMIT 4; -- gives 2 rows SELECT * FROM testcf LIMIT 5; -- gives 3 rows {noformat} -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira