FW: Browse lookup - odd behavior

[Jay R. Ashworth]

On Fri, Jul 16, 2004 at 12:47:08PM -0400, Kenneth Brody wrote:
> "Jay R. Ashworth" wrote:
> [...]
> > > Or are you suggesting actually re-running the lookup in its entirety?
> > 
> > Doing anything else seems semantically inadequate, as this problem
> > demonstrates.
> 
> After some investigation last night, it appears that I misrembered how
> the pkeep part of the browse lookup works.
> 
> Upon re-executing the pkeep lookup, it is only the initial record whose
> position is cached.  From there, the rest of the browse window is repopulated
> by scanning the file.

Hmmm... as fast as index lookups have always been (and I'll grant ya'll
this: index lookups have *always* been breathtakingly fast, even on
Xenix, on a 386-16 :-), did you actually win much by doing that?

> While within the browse, the record numbers are cached so that scrolling
> within the window does not re-scan the file.  Also, when scrolling off the
> end of the window, everything is shifted within the cache, and only the
> newly-vacated area is populated by continuing the scan of the flie.

Ah.

> Since my misremembering of the caching fit the symptoms being reported, I
> thought that I remembered correctly.

Happens.

> Which brings us back to the OP's symptoms.
> 
> We would need more specifics of what the index is built on, which record
> is being deleted, what is in the newly-created record that's replaced it,
> specifically the field(s) used to build that index, what records appear in
> the window upon re-executing the browse lookup, and perhaps some more
> information that I'm not thinking of at this moment.

Which suggests that there *is* something broken, maybe.

Cheers,
-- jra
-- 
Jay R. Ashworth                                                jra at baylink.com
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