Re: FATAL: lock file "postmaster.pid" already exists

FindFirstFile can take a wildcard filename
pattern.  It appears that we are effectively
calling FindFirstFile without a pattern, getting
all 56000 file names with complete stat
information, doing a poor-man's regex on
those names, and matching just the temporary
files.

If RemovePgTempFiles were modified to
pass a filter, this code might perform better
on Windows.  I'll look into this.

________________________________
From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Mark Dilger <markdilger(at)yahoo(dot)com>
Cc: deepak <deepak(dot)pn(at)gmail(dot)com>; Alban Hertroys <haramrae(at)gmail(dot)com>; "pgsql-general(at)postgresql(dot)org" <pgsql-general(at)postgresql(dot)org>
Sent: Wednesday, May 23, 2012 4:25 PM
Subject: Re: [GENERAL] FATAL: lock file "postmaster.pid" already exists

Mark Dilger <markdilger(at)yahoo(dot)com> writes:
> I am running this code on Windows 2003.  It
> appears that postgres has in src/port/dirent.c
> a port of readdir() that internally uses the
> WIN32_FIND_DATA structure, and the function
> FindNextFile() to iterate through the directory.
> Looking at the documentation, it seems that
> this function does collect file creation time,
> last access time, last write time, file size, etc.,
> much like performing a stat.

> In my case, the code is iterating through roughly
> 56,000 files.  Apparently, this is doing the
> equivalent of a stat on each of them.

That would explain it all right.  I think you're basically screwed here,
because so far as I can see Windows doesn't provide any means to
enumerate a directory's contents without fetching that info; at least
http://msdn.microsoft.com/en-us/library/windows/desktop/aa364232(v=vs.85).aspx
doesn't seem to offer any substitutes for FindFirstFile/FindNextFile.

It's barely possible that using FindFirstFileEx with fInfoLevelId =
FindExInfoBasic would save enough to be useful, except that that option
doesn't exist on Windows 2003 anyway.

Consider using another operating system ...

            regards, tom lane