[Xapian-discuss] postlist-errors due to already fixed bugs or not?

[Olly Betts]

On Fri, May 14, 2004 at 08:20:28PM +0200, Arjen van der Meijden wrote:
> I discovered that our current postlist-database contains, according to 
> quartzcheck, a lot of small errors. The termslist doesn't contain errors 
> and I haven't checked the positionlist.

Quartzcheck checks the Btree structures are consistent, but at present
only checks the data held *in* the Btrees for the postlist table.

> Here is the last "screen" of output:

The checker may not resync gracefully after detecting an error (the
segmentation fault which ends the checking is an extreme example of
this).  What are the first few errors?

It's possible the file is fine and that the checking code is wrong.
I wrote it quite recently so it's not had much use, and may handle
a corner case incorrectly.  If I know the first few errors, I can
look at that part of the code to see.

Or does this database exhibit problems in normal use too?

> This database has been created with a cvs-version of Apr 7 2004, so it 
> may have gone corrupted due to flaws in this version, which have already 
> been fixed in version 0.8.0

The last relevant bug fix prior to 0.8.0 was:

  Fri Mar 26 22:33:30 GMT 2004  Olly Betts <olly@survex.com>

        * backends/quartz/quartz_database.cc: Fix problems with termfreq and
          collfreq in postlist getting out of step when a recently modified
          or deleted document is deleted or remodified.

That sounds similar to what you're seeing, but the version you're using should
have this fix in.

> But my question is, can anyone assure me this has been fixed or is 
> otherwise a result of our setup and not a present bug in xapian?

Not without further investigation I'm afraid.

Cheers,
    Olly