Re: corrupted tuple (header?), pg_filedump output

Eric Parusel <lists(at)globalrelay(dot)net> writes:
> Is this what you're speaking of?

> <Data> ------
> Item 1 -- Length: 1756 Offset: 3200 (0x0c80) Flags: USED
> Item 2 -- Length: 1728 Offset: 6464 (0x1940) Flags: USED
> Item 3 -- Length: 1756 Offset: 1444 (0x05a4) Flags: USED
> Item 4 -- Length: 184 Offset: 1260 (0x04ec) Flags: USED
> Item 5 -- Length: 194 Offset: 1064 (0x0428) Flags: USED
> Item 6 -- Length: 164 Offset: 6300 (0x189c) Flags: USED
> Item 7 -- Length: 0 Offset: 1720 (0x06b8) Flags: 0x00
> Item 8 -- Length: 1344 Offset: 4956 (0x135c) Flags: USED
> Item 9 -- Length: 0 Offset: 1064 (0x0428) Flags: 0x00

Well, scratch that theory: those offsets and sizes all seem perfectly
consistent (eg, one ends where the next begins, modulo some alignment
padding in one case). So it's hard to credit that the itemid got
bombed; the corruption has to be in the tuple header itself. What
does the hex dump of the tuple header and vicinity look like?

> Oh crap, I just noticed that there is more than just that item that's
> inconsistent...

> Item 6 -- Length: 164 Offset: 6300 (0x189c) Flags: USED
> XMIN: 1852400896 CMIN: 1970348133 XMAX: 543424609 CMAX|XVAC:
> 1869112179
> Block Id: 1819244288 linp Index: 29295 Attributes: 2667 Size: 101
> infomask: 0x7270
> (HASOID|XMIN_INVALID|MARKED_FOR_UPDATE|UPDATED|MOVED_OFF)
> Error: Computed header length not equal to header size.
> Computed <32> Header: <101>

> Item 8 -- Length: 1344 Offset: 4956 (0x135c) Flags: USED
> XMIN: 2100285 CMIN: 1644759593 XMAX: 1634148473 CMAX|XVAC: 2003137536
> Block Id: 2036411953 linp Index: 103 Attributes: 28524 Size: 108
> infomask: 0x6162 (HASVARWIDTH|XMIN_COMMITTED|UPDATED|MOVED_OFF)
> Error: Computed header length not equal to header size.
> Computed <28> Header: <108>

Those look kinda clobbered too. Maybe you should just send along the
whole -i -f page dump?

regards, tom lane