RE: [PHP] MySQL performance question

From: Date: Mon, 05 Aug 2002 11:09:41 +0000
Subject: RE: [PHP] MySQL performance question
References: 1  Groups: php.general 
Request: Send a blank email to php-general+get-111198@lists.php.net to get a copy of this message
I'm sure it's the first one. Look up the BENCHMARK() function in the manual and see which one is faster. (MySQL manual, btw) ---John Holmes... > -----Original Message----- > From: Lars Olsson [mailto:lasso@lassoweb.nu] > Sent: Sunday, August 04, 2002 4:28 PM > To: php-general@lists.php.net > Subject: [PHP] MySQL performance question > > Hi all! > > Sorry for being slightly off topic, but this list seems to have it's > fair share of MySQL gurus... :-) Anyway, here's my question: > > Suppose I create a table (called table1) which has a field with only > unique values (called id). Now suppose this table has some rows and that > I want to select ONE of them. I usually do this: > > "SELECT * FROM table1 WHERE id=somevalue" > > Since id is a unique value this can only return (at most) 1 row. Now > let's try this: > > "SELECT * FROM table1 WHERE id=somevalue LIMIT 1" > > This query will produce exactly the same result as the first query. But > which one (if any) of the two queries are the most efficient? Is it > > a) The first one, since it's a less complicated SQL query (less time to > parse) > b) The second one, since it will restrict MySQL from searching further > whenever a row is found > > Any opinions? > > /lasso (lasso@lassoweb.nu) > > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php

« previous php.general (#111198) next »