Attached is a patch that changes "sequential" to "ever-increasing".
> Justin Clift <[EMAIL PROTECTED]> writes:
> > I would have though that after 00000000000000FE would be
> > 0000000000000100, not 0000000100000000.
>
> This is the intended behavior, I believe. The low-order half is a
> 32-bit byte offset DIV XLogSegSize --- we could compress out the zero
> bits, but only at the cost of wiring an assumption about XLogSegSize
> into the filename format. The reason that 0/FF is missing from the
> sequence is stated in xlog.h:
>
> /*
> * We break each logical log file (xlogid value) into 16Mb segments.
> * One possible segment at the end of each log file is wasted, to ensure
> * that we don't have problems representing last-byte-position-plus-1.
> */
> #define XLogSegSize ((uint32) (16*1024*1024))
> #define XLogSegsPerFile (((uint32) 0xffffffff) / XLogSegSize)
> #define XLogFileSize (XLogSegsPerFile * XLogSegSize)
>
> > Just checked through the Interactive docs (not sure which version of 7.1
> > they are) and says the numbers should be sequential.
>
> This would seem to be an oversimplification in the docs.
>
> regards, tom lane
>
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--
Bruce Momjian | http://candle.pha.pa.us
[EMAIL PROTECTED] | (610) 853-3000
+ If your life is a hard drive, | 830 Blythe Avenue
+ Christ can be your backup. | Drexel Hill, Pennsylvania 19026
Index: doc/src/sgml/wal.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/wal.sgml,v
retrieving revision 1.9
diff -c -r1.9 wal.sgml
*** doc/src/sgml/wal.sgml 2001/09/09 23:52:12 1.9
--- doc/src/sgml/wal.sgml 2001/09/22 03:58:39
***************
*** 137,143 ****
divided into 8 kB pages. The log record headers are described in
<filename>access/xlog.h</filename>; record content is dependent on
the type of event that is being logged. Segment files are given
! sequential numbers as names, starting at
<filename>0000000000000000</filename>. The numbers do not wrap, at
present, but it should take a very long time to exhaust the
available stock of numbers.
--- 137,143 ----
divided into 8 kB pages. The log record headers are described in
<filename>access/xlog.h</filename>; record content is dependent on
the type of event that is being logged. Segment files are given
! ever-increasing numbers as names, starting at
<filename>0000000000000000</filename>. The numbers do not wrap, at
present, but it should take a very long time to exhaust the
available stock of numbers.
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TIP 4: Don't 'kill -9' the postmaster
