On Fri, Sep 18, 2009 at 9:47 AM, Marcelo Sosa - LST <listas@askterisk.com> wrote:
Hello,
I know that mysql is dumb, but i´m postgresql-fobic :) (i was happy using pgsql, until i found a bug in the restore of backups, that makes the backup unable to be restored, very bad day) :-)
huh, really?
Anyway, I was refering to the change from "digits IN (a list of digits)" to "(digits='xx' OR digits='xxx')", not the quote_in_list option that i found when i was touching a bit of code. For the list-archives then, mysql may prefer a different query format to speed up lcr matches. I´ll test with postgres and check it has any differences by using one method or another, if not may be we can change the code so it uses the fastest way for mysql.
OR list instead of IN list? <sigh/> What is the size of your rate table? When trying both ways, what is the measured difference in performance? Does mysql have a way to analyze the table to ensure it's statistics are up to date?
Regards, Marcelo Sosa
----- Original Message ----- From: "Rupa Schomaker" <rupa@rupa.com> To: <freeswitch-users@lists.freeswitch.org> Sent: Friday, September 18, 2009 11:07 AM Subject: Re: [Freeswitch-users] mod_lcr and indexes
Hmm.... This is because mysql is "dumb" :( Anyway, if you wanted quoted digits, there is an option to enable that in the mod_lcr config file.
http://wiki.freeswitch.org/wiki/Mod_lcr#Advanced_Usage
Specifically, look at the parameter: quote_in_list
The most efficient way (that I know of) to use mod_lcr is to use postgresql and the prefix postgres module which uses a custom datatype and a GIST index for the prefix column.
On Thu, Sep 17, 2009 at 9:24 PM, Marcelo Sosa - LST <listas@askterisk.com> wrote:
Hello all,
This is my first message on the list, i´m pretty new to FS. I was playing a bit with mod_lcr and found that the sql query for fetching the lowest rate can be changed to a better use of indexes, at least on mysql. Anyone can do some test using other DBs?
The change i've made was simple, the original query was something about "... AND digits IN (12345, 1234, 123, 12, 1) ..." and using EXPLAIN i saw that it was using carrier_id as key for the biggest table and not digits. I've changed the code so the query is " AND (digits='12345' OR digits='1234' OR digits='123' OR digits='12' OR digits='1') " and mysql uses the index from the digits row, reducing the returned resultset of the subquery from all the digits from a carrier to the number of "OR" in the query (in my case, from 19850+ to 14).
Anyone think that this may be a nice change? or it is just a bad use of indexes by mysql?
Regards, Marcelo Sosa _______________________________________________ FreeSWITCH-users mailing list FreeSWITCH-users@lists.freeswitch.org http://lists.freeswitch.org/mailman/listinfo/freeswitch-users UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users http://www.freeswitch.org
-- -Rupa
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-- -Rupa