Skip site navigation (1) Skip section navigation (2)

Re: [HACKERS] fork/exec problem: DynaHashCxt

From: Claudio Natoli <claudio(dot)natoli(at)memetrics(dot)com>
To: 'Tom Lane' <tgl(at)sss(dot)pgh(dot)pa(dot)us>,Claudio Natoli <claudio(dot)natoli(at)memetrics(dot)com>
Cc: "'pgsql-hackers(at)postgresql(dot)org'" <pgsql-hackers(at)postgresql(dot)org>,'PostgreSQL Win32 port list' <pgsql-hackers-win32(at)postgresql(dot)org>
Subject: Re: [HACKERS] fork/exec problem: DynaHashCxt
Date: 2003-12-03 04:48:42
Message-ID: A02DEC4D1073D611BAE8525405FCCE2B028065@harris.memetrics.local (view raw or flat)
Thread:
Lists: pgsql-hackerspgsql-hackers-win32
> I'm not sure if you're confusing backend-local hashes with shared
> hashes, or hash control headers with the actual shared data.  But
> the above is a false statement.  DynaHashCxt is not shared.

No, wasn't confused over that. Was confused over something else though :-)

 
> Shared hashes are a bit tricky because there is a backend-local
> structure that has a pointer into the shared memory --- is that
> what's confusing you?

That's pretty much right on the mark, and the heart of the problem I
suspect. 

So this means we'll have to pull relHash out of the shared FreeSpaceMap
structure and make it a variable in it's own right? [Same goes for lockHash
and proclockHash in the LockMethod structure reference by "LockTable (lock
method table)"]


> Keep in mind that this code did work in a fork/exec context not
> so many moons ago.  If you think you see a showstopper, it's a
> relatively recent change and can be undone.

Keeping this firmly in mind, trust me.

Thanks,
Claudio

--- 
Certain disclaimers and policies apply to all email sent from Memetrics.
For the full text of these disclaimers and policies see 
<a
href="http://www.memetrics.com/emailpolicy.html">http://www.memetrics.com/em
ailpolicy.html</a>

Responses

pgsql-hackers by date

Next:From: Tom LaneDate: 2003-12-03 05:01:53
Subject: Re: [HACKERS] fork/exec problem: DynaHashCxt
Previous:From: Lamar OwenDate: 2003-12-03 04:13:47
Subject: Re: rebuilding rpm for RH9 error

pgsql-hackers-win32 by date

Next:From: Tom LaneDate: 2003-12-03 05:01:53
Subject: Re: [HACKERS] fork/exec problem: DynaHashCxt
Previous:From: Tom LaneDate: 2003-12-03 04:12:04
Subject: Re: [HACKERS] fork/exec problem: DynaHashCxt

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group