Subject RE: [IB-Architect] Fw: Slow deletion on large tables
Author Claudio Valderrama C.
> -----Original Message-----
> From: Ann Harrison [mailto:harrison@...]
> Sent: Domingo 28 de Mayo de 2000 12:17

[question about deletion of blobs]

> I do not believe that the problem is with blobs, but rather with
> the indexes.
> Without reproducing the test (which I will do, but not today) I'd
> guess they
> have some indexes with significant numbers of duplicates. The process of
> garbage collecting a blob is this: if a record contains a blob
> id, determine
> which type of blob storage is used. If the blob is on page, release the
> line index indicator. If the blob is on a page by itself, mark that page
> as free in the page indicator. If the blob is on a series of pages, read
> the blob index and free all the pages. Note that none of this requires
> retrieving the blob page itself.

That's the explanation I lacked. Thanks. Now it's clear blobs in this case
aren't a great performance hit. How about updating blobs, please? It's a
subject that has me "on hold". Also, when you say "If the blob is on page,
release the
line index indicator.", do you mean in the same page than the rest of the
record? What's the size limit for that, the available space on the page, the
segment size, some formula?

> The index duplicate problem is architectural, but solutions exist.
> Ann

Then we need to collect a list of recommendations, probably.

> Claudio - I can't get to the news group at the moment, could you forward
> this there?

I will forward even if I take a day, promised. The problem is became an unresolved IP address... did these guys
reconfigure the servers or did they fail to pay the name registration? :-)
The old and deprecated is working, tough. I will try a
separate connection... because if I change the current news alias, probably
Outlook Express will become crazy... being a MS product, you know. :-)

Your answer was finally sent through the old news server... by using
ping -t at the same time to help the connection. :-)