[Firebird-devel] External Files

[Paul B. <pa...@wa...>]

I just wanted to float a problem by you and see if what I am proposing makes
sense and can be added into Firebird as an improvement.
Nothing earth shattering, as I am still getting back to grips with C.

There currently is a limit on the number of external files that can be open
at any one time. This limit is set at 1024 on all non windows systems (as
defined in stdio.h).
Solaris on the other hand is a special case :-), but thats not what this is
about.Wheras on Windows the limit is actually 512.

I have a customer who needs a much bigger limit.

When Firebird accesses an external file the file is fopened and a file
handle is allocated and not released until the database is no longer in use.

In MSDN:

"C run-time I/O now supports many more open files on Win32 platforms than in
previous versions. Up to 2,048 files may be open simultaneously at the lowio
level (that is, opened and accessed by means of the _open, _read, _write,
and so forth family of I/O functions). Up to 512 files may be open
simultaneously at the stdio level (that is, opened and accessed by means of
the fopen, fgetc, fputc, and so forth family of functions). The limit of 512
open files at the stdio level may be increased to a maximum of 2,048 by
means of the _setmaxstdio function."

As such by putting the following in ext.c in the ext_file function
#ifdef WIN32
_setmaxstdio(2048);
#endif

The limit on the number of external files can be increased significantly.

Not a major fix, but a nice to have.
Comments?


Regards
Paul Beach
Main Tel (UK):+44 (0) 1844 354465
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