Re: [HACKERS] open item: tablespace handing in pg_dump/pg_restore

Reini Urban schrieb:
> Tom Lane schrieb:
>> Bruce Momjian <[email protected]> writes:
>>
>>> I am confused.  CVS has in port.h:
>>> so you should already be calling the junction code on Cygwin.
> 
> true. didn't thought of that. very strange.
> 
>> Yeah, I'm sure he is, but it looks from the regression results like it
>> doesn't quite work on Cygwin.  Is that fixable?  
> 
> I'll step that in the debugger.

not yet done.

>> If so, we'd have a choice of whether to rely on junctions or on
>> Cygwin's own emulation of symlinks. I'd be inclined to think the
>> former is a better idea,
>> if only because it'd give you some chance of migrating a data
>> directory between Cygwin and native ports.
> 
> Cygwin can do symlinks for directories via the magic .lnk file.
> But Cygwin can also do junctions via hardlinks in ln.exe.
> I thought link() calls the junction code.
> I'll investigate why the libc link() failed, and if ln.exe does some 
> sifferent magic, similar to pgsymlink.

For the records:

Using cygwin native slow symlinks - see attached patch - works fine.
Quite an overhead via the magic .lnk file.
tablespace tests pass.

Should I investigate what users want?

1. speed:
   * junctions, can only be manipulated via junction.exe
    (sysinternals.com e.g.)
   * only w2k and above,
2. or compatibility:
   * .lnk, can be manipulated with ln.exe
   * all windows version. even win95 when we fix
     our outstanding cygserver issues with cygserver

-----------------
But another problem arose. Doesn't look like a sideeffect caused by my 
symlink switch. I switched to latest CVS in between.

parallel_schedule always fails after finishing create_misc, independent 
of the order. If it's the first 2nd, 3rd, ...
so it's not create_aggregate or any other test there.

This is the tail of postmaster.log:
ERROR:  aggregate nosuchagg(*) does not exist
ERROR:  operator does not exist: integer ######
ERROR:  syntax error at or near ")" at character 45
ERROR:  syntax error at or near "IN" at character 43
ERROR:  new row for relation "check_tbl" violates check constraint 
"check_con"
ERROR:  new row for relation "check_tbl" violates check constraint 
"check_con"
ERROR:  new row for relation "check_tbl" violates check constraint 
"check_con"
ERROR:  new row for relation "check2_tbl" violates check constraint 
"sequence_con"
ERROR:  new row for relation "check2_tbl" violates check constraint 
"sequence_con"
ERROR:  new row for relation "check2_tbl" violates check constraint 
"sequence_con"
ERROR:  new row for relation "check2_tbl" violates check constraint 
"sequence_con"
-- 
Reini Urban
http://xarch.tu-graz.ac.at/home/rurban/


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--- postgresql-8.0.0cvs/src/backend/commands/tablespace.c.orig	2004-08-30 04:54:38.000000000 +0200
+++ postgresql-8.0.0cvs/src/backend/commands/tablespace.c	2004-10-07 14:24:11.731406400 +0200
@@ -51,6 +51,10 @@
  */
 #include "postgres.h"
 
+#ifdef __CYGWIN__
+#undef symlink
+#endif
+
 #include <unistd.h>
 #include <dirent.h>
 #include <sys/types.h>