[Asterisk-Users] options for mysql query from dialplan

[Damon Estep]

I am using realtime mysql for extensions, sip, and voicemail.

Outbound call routing does not really perform well in realtime
extensions due to the high number of rows in the database (300k), so I
can not use it. It appears with my limited knowledge that the query
method is not robust enough for large databases.

Given the fact that I already have realtime and mysql configured, what
are my options for running a mysql query from the dialplan to find the
provider I want to use for outbound. 

I am not looking for a complete solution, just a hint on the best way to
query my existing mysql database from the dialplan.

I have looked at the MySQL command, and there are a lot of notes about
connection closing and other scary stuff? Does it work?

Are there other native options given the fact that realtime is
configured and in use?

The goal is to run a query against a database like this

SELECT provideralias FROM ldproviders WHERE npa = (digits 2 thru 4 of
dialed number) AND nxx = (digits 5 thru 7)

Then take the provider alias returned and
Dial(SIP/${EXTEN}@${provideralias},60).

Next step would be to add a loop for multiple providers, starting with
the lowest cost.

Any hints or comments from the pros?

TIA

Damon