Bug #16722 Fulltext: implicit limit for query word number (depends on length of the query)
Submitted: 23 Jan 2006 11:42 Modified: 2 Feb 2006 16:56
Reporter: Sergey Vojtovich Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server Severity:S2 (Serious)
Version:5.1 OS:Any (any)
Assigned to: Sergey Vojtovich CPU Architecture:Any

[23 Jan 2006 11:42] Sergey Vojtovich
Description:
This bug affects custom fulltext parsers only, built-in parser works just fine.

The problem is that MySQL has implicit limit for query word number which depends on length of the query:

limit= 1 + query_length / 2;

E.g.: 'AAAA' query length is 4, the limit is 3 words per this query, but if the parser expands query to 4 words ('test1', 'test2', 'test3', 'test4') it results in unexpected behavior. Note that query 'AAAAAA' works just fine.

How to repeat:
N/A
[25 Jan 2006 9:49] Bugs System
A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/internals/33384
[26 Jan 2006 11:13] Bugs System
A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/1668
[30 Jan 2006 13:32] Sergey Vojtovich
Fixed in 5.1.6.
Removed implicit limit for query word number.
[2 Feb 2006 16:56] Mike Hillyer
Documented in 5.1.6 changelog:

   <listitem>
        <para>
          Word limit removed from FULLTEXT to improve compatibility with
          custom parsers. (Bug #16722)
        </para>
      </listitem>