Is the a "magic number" for WAL files
I would like the "file" command to tell me something other than "data",
yes even though I can tell by the name (and the directory of course).
Hoping someone has something I can slip into /usr/share/misc/magic.mgc
or that directory.
Along the same lines, what info is embedded in the file name? I see that
the second non-zero recently went from 2 to 3. Significance?
0000000100000030000000CF
^
--------------|
On 9 December 2011 18:46, Rob Sargent <robjsargent@gmail.com> wrote:
Along the same lines, what info is embedded in the file name? I see that
the second non-zero recently went from 2 to 3. Significance?0000000100000030000000CF
^
--------------|
The WAL file name consists of timeline, segment set/segment block and
segment, Once the segment (the last 8 characters of the file name)
reaches 000000FE, the next file will have a segment 00000000 but
characters 9-16 will increment their value to reflect this wraparound.
So it's not any more significant that 1 added to 99 results in it
becoming 00 with a 1 before it.
--
Thom
On 9 December 2011 18:46, Rob Sargent <robjsargent@gmail.com> wrote:
I would like the "file" command to tell me something other than "data",
yes even though I can tell by the name (and the directory of course).
Hoping someone has something I can slip into /usr/share/misc/magic.mgc
or that directory.
You mean something like this?:
/*
* Each page of XLOG file has a header like this:
*/
#define XLOG_PAGE_MAGIC 0xD068 /* can be used as WAL version indicator */
Obviously that isn't stable.
--
Peter Geoghegan http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training and Services