RE: pgbench bug / limitation

Hello Tom,

Thanks a ton for such quick reply. Ok, so ppoll() would be available on Linux right..?
I just installed postgres 12.2 on windows & got it as part of the install.
What would you advise me to do..?

Thanks
Manish

-----Original Message-----
From: Tom Lane <tgl@sss.pgh.pa.us>
Sent: Thursday, May 28, 2020 11:02 PM
To: Jawarilal, Manish
Cc: pgsql-bugs@lists.postgresql.org
Subject: Re: pgbench bug / limitation


[EXTERNAL EMAIL]

"Jawarilal, Manish" <Manish.Jawarilal@dell.com> writes:
> OS: Windows 10
> C:\Program Files\PostgreSQL\12\bin>pgbench.exe -c 120 -r -T 3600 -h
> <DBServerName> -p 9432 -U DBUser testdb too many client connections
> for select()

Yeah ... pgbench can support fairly large connection counts on platforms that have ppoll(), but Windows does not.
Withoutppoll() we fall back to select() which may not allow more than 100 or so. 

Having said that ... it looks like pgbench thinks it can override Windows' default setting:

#ifdef WIN32
#define FD_SETSIZE 1024            /* must set before winsock2.h is included */
#endif

and some googling confirms that indeed that should work.  How did you build or come by this copy of pgbench?

            regards, tom lane