[jira] [Created] (DERBY-7173) Very poor performance with a = ? AND b = ? OR a = ? AND b = ? in query

[Richard Evans (Jira)]

Richard Evans created DERBY-7173:
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             Summary: Very poor performance with a = ? AND b = ? OR a = ? AND b 
= ? in query
                 Key: DERBY-7173
                 URL: https://issues.apache.org/jira/browse/DERBY-7173
             Project: Derby
          Issue Type: Bug
          Components: SQL
    Affects Versions: 10.16.1.1
            Reporter: Richard Evans
         Attachments: lkp.java

Execute a query like:

SELECT * FROM table WHERE col1 = ? AND col2 = ? OR col1 = ? AND col2 = ?

Performance is significantly worse then the simpler:

SELECT * FROM table WHERE col1 = ? AND col2 = ? 

even though both col1 and col2 are indexed.

Simple test case attached - run with db directory and number of OR clauses in 
query - use 2 for first example above and 1 for second.



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