Thread: contrib/pg_buffercache

From:
"Andrew Dunstan"
Date:

... is apparently broken for Windows and Cygwin. See for example
http://www.pgbuildfarm.org/cgi-bin/show_log.pl?nm=loris&dt=2005-03-16%2001:55:33
cheers

andrew




From:
Mark Kirkwood
Date:

Andrew Dunstan wrote:
> ... is apparently broken for Windows and Cygwin. See for example
> http://www.pgbuildfarm.org/cgi-bin/show_log.pl?nm=loris&dt=2005-03-16%2001:55:33
> cheers

hmmm - never tried to compile it on win32! I am getting http 502 from 
the above url, so I will have a go at building on win32 tomorrow.

cheers

Mark


From:
Mark Kirkwood
Date:

Andrew Dunstan wrote:
> ... is apparently broken for Windows and Cygwin. See for example
> http://www.pgbuildfarm.org/cgi-bin/show_log.pl?nm=loris&dt=2005-03-16%2001:55:33
>

Andrew,

The attached patch seems to sort it for me, can you give it try on win32
and cygwin?

cheers

Mark
--- pg_buffercache_pages.c.orig    Sun Mar 13 04:36:24 2005
+++ pg_buffercache_pages.c    Wed Mar 16 20:57:52 2005
@@ -17,6 +17,11 @@

 #define NUM_BUFFERCACHE_PAGES_ELEM    6

+#ifdef WIN32
+extern DLLIMPORT BufferDesc        *BufferDescriptors;
+extern DLLIMPORT volatile uint32    InterruptHoldoffCount;
+#endif
+

 /*
  * Record structure holding the to be exposed cache data.

From:
Andrew Dunstan
Date:

It fixes the build error on Windows - haven't tried because i don't have
time, but I know it won't work on Cygwin, because WIN32 isn't (usually)
defined on Cygwin - see previous almost endless discussions.

cheers

andrew

Mark Kirkwood wrote:

> Andrew Dunstan wrote:
>
>> ... is apparently broken for Windows and Cygwin. See for example
>> http://www.pgbuildfarm.org/cgi-bin/show_log.pl?nm=loris&dt=2005-03-16%2001:55:33
>>
>>
>
> Andrew,
>
> The attached patch seems to sort it for me, can you give it try on
> win32 and cygwin?
>
> cheers
>
> Mark
>
>------------------------------------------------------------------------
>
>--- pg_buffercache_pages.c.orig    Sun Mar 13 04:36:24 2005
>+++ pg_buffercache_pages.c    Wed Mar 16 20:57:52 2005
>@@ -17,6 +17,11 @@
> 
> #define NUM_BUFFERCACHE_PAGES_ELEM    6
> 
>+#ifdef WIN32
>+extern DLLIMPORT BufferDesc        *BufferDescriptors;
>+extern DLLIMPORT volatile uint32    InterruptHoldoffCount;
>+#endif
>+
> 
> /*
>  * Record structure holding the to be exposed cache data.
>  
>
>------------------------------------------------------------------------
>
>
>---------------------------(end of broadcast)---------------------------
>TIP 1: subscribe and unsubscribe commands go to 
>  
>


From:
Mark Kirkwood
Date:

Andrew Dunstan wrote:
> It fixes the build error on Windows - haven't tried because i don't have
> time, but I know it won't work on Cygwin, because WIN32 isn't (usually)
> defined on Cygwin - see previous almost endless discussions.
>

Yes - I recall that discussion a while ago.

This patch should sort the issue.

One question, should I be using defined(__MINGW32__) as opposed to
defined(WIN32)? I figured I didn't as in this case it is not necessary
to distinguish between native and cygwin.

regards

Mark




*** pg_buffercache_pages.h.orig    Thu Mar 17 10:12:20 2005
--- pg_buffercache_pages.h    Thu Mar 17 13:44:45 2005
***************
*** 15,18 ****
--- 15,24 ----

  extern Datum pg_buffercache_pages(PG_FUNCTION_ARGS);

+ /* A little hackery for Windows and Cygwin */
+ #if defined (WIN32) || defined (__CYGWIN__)
+ extern DLLIMPORT BufferDesc            *BufferDescriptors;
+ extern DLLIMPORT volatile uint32    InterruptHoldoffCount;
+ #endif
+
  #endif  /* PG_BUFFERCACHE_PAGES_H */


From:
Andrew Dunstan
Date:


Mark Kirkwood wrote:

> Andrew Dunstan wrote:
>
>> It fixes the build error on Windows - haven't tried because i don't have
>> time, but I know it won't work on Cygwin, because WIN32 isn't (usually)
>> defined on Cygwin - see previous almost endless discussions.
>>
>
> Yes - I recall that discussion a while ago.
>
> This patch should sort the issue.
>
> One question, should I be using defined(__MINGW32__) as opposed to
> defined(WIN32)? I figured I didn't as in this case it is not necessary
> to distinguish between native and cygwin.
>
>

You figured correctly.

cheers

andrew

From:
Mark Kirkwood
Date:

Andrew Dunstan wrote:
> 
> Mark Kirkwood wrote:
> 
> 
>>Andrew Dunstan wrote:
>>
>>
>>>It fixes the build error on Windows - haven't tried because i don't have
>>>time, but I know it won't work on Cygwin, because WIN32 isn't (usually)
>>>defined on Cygwin - see previous almost endless discussions.
>>>
>>
>>Yes - I recall that discussion a while ago.
>>
>>This patch should sort the issue.
>>
>>One question, should I be using defined(__MINGW32__) as opposed to
>>defined(WIN32)? I figured I didn't as in this case it is not necessary
>>to distinguish between native and cygwin.
>>
>>
> 
> 
> You figured correctly.
> 

Oh, and thanks to your efforts with the automated build system this gets 
picked up now instead of lurking till after release - great work!

cheers

Mark



From:
Ioannis Theoharis
Date:



Hi,

in case one use 'inherits' relationship to create a hierarchy of
tables, table 'pg_inherits' stores for each table the information of which
is its parent table.

During the evaluation of a query like
select * from Root;
where Root is the 'root' table of our hierarchy, postgreSQL needs to
find which tables are involved in the result (which tables belong to the
hierarchy).

My question is whether the way, in wich postgresql do this task, is a
transitive closure on table 'pg_inherits' or there is a better approach
implemented (like numbering scheme techniques etc.) ?

If there is a related url, please send it to me.



From:
Ioannis Theoharis
Date:


Also i'd like to answer you if postgresQL has implemented rcursive queries
proposed from SQL99 standard?

If yes, are there any restrictions of the model on your implementation?



From:
Tom Lane
Date:

Ioannis Theoharis <> writes:
> My question is whether the way, in wich postgresql do this task, is a
> transitive closure on table 'pg_inherits' or there is a better approach
> implemented (like numbering scheme techniques etc.) ?

It's a transitive closure, and not a very bright one at that; see
find_all_inheritors(), find_inheritance_children(), and particularly
the comments to the latter.  However, we've not heard reports indicating
that this is a serious bottleneck in any real-world situation, so
no one has spent time to improve it.  (I'd expect the per-table planning
costs to vastly outweigh the cost of finding those tables, anyway.)
        regards, tom lane