Beefy Boxes and Bandwidth Generously Provided by pair Networks
Problems? Is your data what you think it is?
 
PerlMonks  

Re: same query, different execution, different performance (server-side--)

by tye (Cardinal)
on Feb 14, 2012 at 01:30 UTC ( #953581=note: print w/ replies, xml ) Need Help??


in reply to same query, different execution, different performance

The one with a placeholder is "more efficient" in that it pre-plans the execution before knowing what value will be stuffed into the placeholder. Unfortunately, without that information, the resulting plan sucks. [By pre-planning at prepare() time, it doesn't have to waste time re-planning every time you execute() the same prepared query.]

I have yet to run into a situation where I had and actually kept "server-side prepare" enabled, despite lots of people wanting to crow about how prepare + placeholders can be such a performance "win".

Luckily, it is easy to disable server-side prepare so that you can still use place-holders while still getting "late" query planning every time you execute(). See pg_server_prepare since we are talking Postgresql.

- tye        


Comment on Re: same query, different execution, different performance (server-side--)

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://953581]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others exploiting the Monastery: (11)
As of 2014-07-29 12:01 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    My favorite superfluous repetitious redundant duplicative phrase is:









    Results (217 votes), past polls