[
https://issues.apache.org/jira/browse/DERBY-3926?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Mamta A. Satoor updated DERBY-3926:
-----------------------------------
Attachment: script3WithUserFriendlyIndexNames.sql
I am attaching a newer version of script3.sql The new script is called
script3WithUserFriendlyIndexNames.sql The only changes made to script3.sql are
to use user-friendly index names so that it is easier to understand the query
which is using index names through optimizer overrides to demonstrate the buggy
behavior. Hopefully it will be easier to read the query plan as well. The query
to see the problem is as follows
SELECT table1.id, table2.value, table3.value FROM --DERBY-PROPERTIES
joinOrder=FIXED
table3 -- DERBY-PROPERTIES index=nonUniqueOnValue_Table3
, table2 -- DERBY-PROPERTIES index=nonUniqueOnValue_Table2
, table1
WHERE table1.id=table2.id AND table2.name='PageSequenceId'
AND table1.id=table3.id
AND table3.name='PostComponentId'
AND table3.value='21857' ORDER BY table2.value;
> Incorrect ORDER BY caused by index
> ----------------------------------
>
> Key: DERBY-3926
> URL: https://issues.apache.org/jira/browse/DERBY-3926
> Project: Derby
> Issue Type: Bug
> Components: SQL
> Affects Versions: 10.1.3.3, 10.2.3.0, 10.3.3.1, 10.4.2.0
> Reporter: Tars Joris
> Assignee: Mamta A. Satoor
> Attachments: derby-reproduce.zip, script3.sql,
> script3WithUserFriendlyIndexNames.sql, test-script.zip
>
>
> I think I found a bug in Derby that is triggered by an index on a large
> column: VARCHAR(1024). I know it is generally not a good idea to have an
> index on such a large column.
> I have a table (table2) with a column "value", my query orders on this column
> but the result is not sorted. It is sorted if I remove the index on that
> column.
> The output of the attached script is as follows (results should be ordered on
> the middle column):
> ID |VALUE |VALUE
> ----------------------------------------------
> 2147483653 |000002 |21857
> 2147483654 |000003 |21857
> 4294967297 |000001 |21857
> While I would expect:
> ID |VALUE |VALUE
> ----------------------------------------------
> 4294967297 |000001 |21857
> 2147483653 |000002 |21857
> 2147483654 |000003 |21857
> This is the definition:
> CREATE TABLE table1 (id BIGINT NOT NULL, PRIMARY KEY(id));
> CREATE INDEX key1 ON table1(id);
> CREATE TABLE table2 (id BIGINT NOT NULL, name VARCHAR(40) NOT NULL, value
> VARCHAR(1024), PRIMARY KEY(id, name));
> CREATE UNIQUE INDEX key2 ON table2(id, name);
> CREATE INDEX key3 ON table2(value);
> This is the query:
> SELECT table1.id, m0.value, m1.value
> FROM table1, table2 m0, table2 m1
> WHERE table1.id=m0.id
> AND m0.name='PageSequenceId'
> AND table1.id=m1.id
> AND m1.name='PostComponentId'
> AND m1.value='21857'
> ORDER BY m0.value;
> The bug can be reproduced by just executing the attached script with the
> ij-tool.
> Note that the result of the query becomes correct when enough data is
> changed. This prevented me from creating a smaller example.
> See the attached file "derby-reproduce.zip" for sysinfo, derby.log and
> script.sql.
> Michael Segel pointed out:
> "It looks like its hitting the index ordering on id,name from table 2 and is
> ignoring the order by clause."
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
