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https://issues.apache.org/jira/browse/CASSANDRA-15064?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Marcus Eriksson updated CASSANDRA-15064:
----------------------------------------
Bug Category: Parent values: Correctness(12982)Level 1 values: API /
Semantic Implementation(12988)
Complexity: Normal
Discovered By: User Report
Status: Open (was: Triage Needed)
[~jmeredithco] anything more to do here?
> Wrong ordering for timeuuid fields
> ----------------------------------
>
> Key: CASSANDRA-15064
> URL: https://issues.apache.org/jira/browse/CASSANDRA-15064
> Project: Cassandra
> Issue Type: Bug
> Components: Cluster/Schema
> Reporter: Andreas Andersen
> Assignee: Jon Meredith
> Priority: Normal
> Attachments: example.cql
>
>
> Hi!
> We're seeing some strange behavior for the ordering of timeuuid fields. They
> seem to be sorted in the wrong order when the clock_seq_low field in a
> timeuuid goes from 7f to 80. Consider the following example:
> {noformat}
> cqlsh:test> show version;
> [cqlsh 5.0.1 | Cassandra 3.11.4 | CQL spec 3.4.4 | Native protocol v4]
> cqlsh:test> CREATE TABLE t (
> ... partition int,
> ... t timeuuid,
> ... i int,
> ...
> ... PRIMARY KEY(partition, t)
> ... )
> ... WITH CLUSTERING ORDER BY(t ASC);
> cqlsh:test> INSERT INTO t(partition, t, i) VALUES(1,
> 84e2c963-4ef9-11e9-b57e-f0def1d0755e, 1);
> cqlsh:test> INSERT INTO t(partition, t, i) VALUES(1,
> 84e2c963-4ef9-11e9-b57f-f0def1d0755e, 2);
> cqlsh:test> INSERT INTO t(partition, t, i) VALUES(1,
> 84e2c963-4ef9-11e9-b580-f0def1d0755e, 3);
> cqlsh:test> INSERT INTO t(partition, t, i) VALUES(1,
> 84e2c963-4ef9-11e9-b581-f0def1d0755e, 4);
> cqlsh:test> INSERT INTO t(partition, t, i) VALUES(1,
> 84e2c963-4ef9-11e9-b582-f0def1d0755e, 5);
> cqlsh:test> SELECT * FROM t WHERE partition = 1 ORDER BY t ASC;
>
> partition | t | i
> -----------+--------------------------------------+---
> 1 | 84e2c963-4ef9-11e9-b580-f0def1d0755e | 3
> 1 | 84e2c963-4ef9-11e9-b581-f0def1d0755e | 4
> 1 | 84e2c963-4ef9-11e9-b582-f0def1d0755e | 5
> 1 | 84e2c963-4ef9-11e9-b57e-f0def1d0755e | 1
> 1 | 84e2c963-4ef9-11e9-b57f-f0def1d0755e | 2
>
> (5 rows)
> cqlsh:test>
> {noformat}
> The expected behavior is that the rows are returned in the same order as they
> were inserted (we inserted them with their clustering key in an ascending
> order). Instead, the order "wraps" in the middle.
> This issue only arises when the 9th octet (clock_seq_low) in the uuid goes
> from 7f to 80. A guess would be that the comparison is implemented as a
> signed integer instead of an unsigned integer, as 0x7f = 127 and 0x80 = -128.
> According to the RFC, the field should be treated as an unsigned integer:
> [https://tools.ietf.org/html/rfc4122#section-4.1.2]
> Changing the field from a timeuuid to a uuid gives the expected correct
> behavior:
> {noformat}
> cqlsh:test> CREATE TABLE t (
> ... partition int,
> ... t uuid,
> ... i int,
> ...
> ... PRIMARY KEY(partition, t)
> ... )
> ... WITH CLUSTERING ORDER BY(t ASC);
> cqlsh:test> INSERT INTO t(partition, t, i) VALUES(1,
> 84e2c963-4ef9-11e9-b57e-f0def1d0755e, 1);
> cqlsh:test> INSERT INTO t(partition, t, i) VALUES(1,
> 84e2c963-4ef9-11e9-b57f-f0def1d0755e, 2);
> cqlsh:test> INSERT INTO t(partition, t, i) VALUES(1,
> 84e2c963-4ef9-11e9-b580-f0def1d0755e, 3);
> cqlsh:test> INSERT INTO t(partition, t, i) VALUES(1,
> 84e2c963-4ef9-11e9-b581-f0def1d0755e, 4);
> cqlsh:test> INSERT INTO t(partition, t, i) VALUES(1,
> 84e2c963-4ef9-11e9-b582-f0def1d0755e, 5);
> cqlsh:test> SELECT * FROM t WHERE partition = 1 ORDER BY t ASC;
>
> partition | t | i
> -----------+--------------------------------------+---
> 1 | 84e2c963-4ef9-11e9-b57e-f0def1d0755e | 1
> 1 | 84e2c963-4ef9-11e9-b57f-f0def1d0755e | 2
> 1 | 84e2c963-4ef9-11e9-b580-f0def1d0755e | 3
> 1 | 84e2c963-4ef9-11e9-b581-f0def1d0755e | 4
> 1 | 84e2c963-4ef9-11e9-b582-f0def1d0755e | 5
>
> (5 rows)
> cqlsh:test>{noformat}
>
>
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