Miernik wrote:
Richard Huxton <[EMAIL PROTECTED]> wrote:
I just installed pgpool2 and whoaaa! Everything its like about 3 times
faster! My application are bash scripts using psql -c "UPDATE ...".
Probably spending most of their time setting up a new connection, then
clearing it down again.
If I do it in Python it could do all queries in the same connection, so
should be faster? Besides that 'psql' is written in perl, so its also
heavy, by not using psql I get rid of perl library in RAM.
Nope - "C" all through.
> Also the
script uses wget to poll some external data sources a lot, also
needlessly opening new connection to the webserver, so I want to make
the script save the http connection, which means I must get rid of wget.
Maybe I should write some parts in C?
BTW, doesn't there exist any tool does what "psql -c" does, but is
written in plain C, not perl? I was looking for such psql replacement,
but couldn't find any
Well ECPG lets you embed SQL directly in your "C".
# Number of connection pools allowed for a child process
max_pool = 1
Might need to increase that to 2 or 3.
Why? The website says:
max_pool
The maximum number of cached connections in pgpool-II children
processes. pgpool-II reuses the cached connection if an incoming
connection is connecting to the same database by the same username.
But all my connections are to the same database and the same username,
and I only ever want my application to do 1 connection to the database
at a time, so why would I want/need 2 or 3 in max_pool?
From the subject line of your question: "how to fix problem then when
two queries run at the same time..."
Of course if you don't actually want to run two simultaneous queries,
then max_pool=1 is what you want.
Not well known enough on the Debian side of the fence? It's simple
enough to install from source though. Takes about one minute.
But is there any advantage for me compared to pgpool2, which works
really nice?
Can't say. Given your limited RAM, it's probably worth looking at both
and seeing which leaves you more memory. Your main concern has got to be
to reduce wasted RAM.
> In some parts, like doing some count(*) stuff, it now does
things in about one second, which took a few minutes to finish before (if
the other part of the scripts where doing something else on the database
at the same time).
That will be because you're only running one query, I'd have thought.
Two queries might be sending you into swap.
--
Richard Huxton
Archonet Ltd
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