Talk About Network

Google


Register and Login
Nick
Password
Register create new account Sign up is FREE and you can post replies, new topics, bookmark posts and more!
Recover lost password


Data Bases > Pgsql General > active queries
Latest [ Topics | Posts ] Archive Post A New Topic Post a Reply
<< Topic < Post Post 1 of 2 Topic 15667 of 17437
Post > Topic >>

active queries

by amiklosi@[EMAIL PROTECTED] (Miklosi Attila) May 27, 2008 at 11:35 AM

Hi!

Our company has a long last problem by using libpq in multi-threaded
programs. The libpq usually closes the programs without any error
message or rarely giving the 'Invalid frontend message type 87' error.
When asked you about this error message you gave the reply below. In the
reply there is only one thing which is not clear... What does an
'active' query mean? Or how can we detect active queries on a PGconn?
We have tried PQcancel() and PQreset() functions too, but they didn't
help solving the problem.
Our programs retrieve every result (PQgetResult() and PQclear()
functions) that is pending on the server before reusing a PGconn.

Thank you in advance
Attila Miklosi

P.S.: this is a copy of your reply to 'invalid frontend message type 87'
error message

>"Invalid frontend message" means the server got a message with an
>unexpected first byte, which usually means the server and libpq got
>out of sync about where the message boundaries are.  It's been quite
>a long time since we've seen an actual bug of that sort, though.
>The cases that I've heard of recently involve multiple threads in an
>application trying to use the same PGconn without any interlocking.
>You can't have multiple queries active on a single connection, but
>libpq itself doesn't contain any locking to prevent multiple threads
>from trying to use the PGconn at once.
>
>If you're getting this with a single-threaded client, please submit
>a test case to pgsql-bugs.
>
>                       regards, tom lane



-- 
Sent via pgsql-general mailing list (pgsql-general@[EMAIL PROTECTED]
)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general
 




 2 Posts in Topic:
active queries
amiklosi@[EMAIL PROTECTED  2008-05-27 11:35:49 
Re: active queries
kleptog@[EMAIL PROTECTED]  2008-05-27 18:59:34 

Post A Reply:
  Go here to Signup

AddThis Feed Button


About - Advertising - Contact - Frequently Asked Questions - Privacy Policy - Terms of Use - Signup

Contact
tan12V112 Sat Nov 22 11:54:02 CST 2008.