RE: [PHP-DB] SQL very fast here & very slow there

Is it possible that the tables at school are not indexed? berber -----Original Message----- From: Paolo Bonavoglia [mailto:paolo.bonavoglia@liceofoscarini.it] Sent: Saturday, January 25, 2003 7:55 PM To: php-db@lists.php.net Subject: Re: [PHP-DB] SQL very fast here & very slow there At 16:43 24/01/2003 24/01/2003, John A DAVIS wrote: >We had a very sluggish SQL Server 7.0 and we tested the RAM chips and >found one to be bad. It was throwing off a whole bank of chips (1gb). >Stuff is a lot faster now. >Also, your indexes might be different on your tables. Indexing the correct >fields, especially the joined fields and ID fields used in searches, >really helps big time. >I'm no expert. At 16:32 24/01/2003 24/01/2003, Brent Baisley wrote: >I'm not sure how Paradox works, but it may be locking problems you are >running into. I know Paradox used to have issues with data changing while >a query was executing. On your home machine you are the only one accessing >the DB, so there wouldn't be any contention. Your home DB probably hits >the cache since the data isn't changing. >How busy is the DB at school? Thanks a lot for your suggestions; sometimes Paradox does have locking problem ... but the DB at school is not very busy, and the tables and web pages I am using are still private, in a password protected area. Indexes are identical So I'm still in doubt. I have checked RAM and indexes at school but everything seems Ok. And I've found something even more strange: I've splitted the SQL query in two: the first uses just the first two tables, and the output table is then visited with a PhP while {} loop which at every step execuste a simple SQL SELECT on the third table; I thought this a much less efficient method to make the web page, and so it is on my home PC, where it takes some 3 or 4 seconds to complete (instead of 1 sec or less); but on the school server the web page takes "only" 15-20 sec, a lot less than before (60sec and even more)! A 3 tables join is too much for the server?? So I've found a (not so good) solution to the problem, but I still do not understand it's nature and this is quite disappointing. >There is really nothing in your question applicable to PHP. Have you >tried >a Paradox list? I'll try, but using the Paradox 9 program the SQL Select executes in a flash at home and at school, there is no measurable difference; maybe the problem is with the ODBC Paradox driver? Paolo Bonavoglia ------------------------------------------------------------------------ --- Docente di Matematica e Fisica Responsabile Lab.Informatica e sito Web Liceo Classico "Marco Foscarini" Cannaregio 4942 I 30121 VENEZIA Tel. 041,5224845 Fax 041,5201657 E-Mail paolo.bonavoglia@liceofoscarini.it ------------------------------------------------------------------------ -- Pagine Web http://www.liceofoscarini.it/ -- PHP Database Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php