Bug #747 | using an index on some regular expressions | ||
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Submitted: | 28 Jun 2003 6:44 | Modified: | 14 Jul 2003 16:57 |
Reporter: | Daniel Penning | Email Updates: | |
Status: | Closed | Impact on me: | |
Category: | MySQL Server | Severity: | S4 (Feature request) |
Version: | OS: | ||
Assigned to: | Peter Gulutzan | CPU Architecture: | Any |
[28 Jun 2003 6:44]
Daniel Penning
[14 Jul 2003 16:57]
Peter Gulutzan
There is another way to accomplish the same effect: use LIKE. If you have an indexed column column1, and you ask "explain select * from table1 where column1 LIKE 'd%'", you will see that the query does cause use of an index. However, we do intend to work toward a "faster REGEXP package". It's already on our list of possible future changes. When we start work (sorry, no dates), we will certainly regard this as a reasonable suggestion for the set of enhancements.
[9 May 2006 19:03]
Mathew Johnston
Note that for the index to be used the regular expression would have to be "rooted" with a '^' (eg, '^somepattern') Without the '^', the regex is supposed to match anywhere within the entire string, not strictly from the beginning.
[8 Feb 2007 23:08]
Mark Lehmann
Has any work been done to optimize anchored regexp queries since 2003?
[18 Feb 2007 18:56]
Peter Gulutzan
For the specific question that was the subject of this feature request, there has been no optimization. Please send questions about the product to a mailing list or to a forum.
[29 Mar 2010 10:32]
eliza sahoo
I also want to shar something similar to this. http://www.mindfiresolutions.com/using-regular-expressions-with-mysql-queries-to-search-75...