4 messages in com.mysql.lists.mysqlRE: Performance: LIMIT 1 with UPDATE| From | Sent On | Attachments |
|---|---|---|
| Robert DiFalco | 29 Aug 2006 09:05 | |
| Robert DiFalco | 29 Aug 2006 10:08 | |
| Rick James | 29 Aug 2006 11:50 | |
| Robert DiFalco | 29 Aug 2006 11:53 |
| Subject: | RE: Performance: LIMIT 1 with UPDATE |
|---|---|
| From: | Rick James (rja...@yahoo-inc.com) |
| Date: | 08/29/2006 11:50:10 AM |
| List: | com.mysql.lists.mysql |
Maybe it is the tiny extra time to parse the unnecessary " LIMIT 1"?
-----Original Message----- From: Robert DiFalco [mailto:rdif...@tripwire.com] Sent: Tuesday, August 29, 2006 10:09 AM To: mys...@lists.mysql.com; inte...@lists.mysql.com Subject: RE: Performance: LIMIT 1 with UPDATE
FWIW, my preliminary testing shows no performance increase for adding LIMIT 1 to the following construct:
[ SELECT | UPDATE ] WHERE Table.UniqueID = <N>
In fact, there seems to be a slight performance edge to NOT appending LIMIT 1 to the statement.
R.
-----Original Message----- From: Robert DiFalco [mailto:rdif...@tripwire.com] Sent: Tuesday, August 29, 2006 9:06 AM To: mys...@lists.mysql.com Subject: Performance: LIMIT 1 with UPDATE
Does using LIMIT 1 with UPDATE provide a performance improvement when the WHERE condition is on a unique index or primary key?
R.
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