How versions are kept in file structure?
How long? Is it possible to configure time period to keep versions and/or
space allocated for versioning?

The issue is that the versioning is a real performance killer: various
strategies exist to deal with that. For example, the SQL table record can be
updated with a last version and previous versions kept in some linked list or
vice versa: a current version is kept in a list while table record contains
the last commited version: this makes a performance .difference for different
scenarious.

-----Original Message-----
From: Ann Harrison [mailto:aharrison@...]
Sent: 11. janúar 2004 18:52
To: firebird-support@yahoogroups.com
Subject: Re: [firebird-support] how read commited is implemented


laimisnd wrote:

>Can anyone share information how FireBird is implementing read
>consistency?
>
>I am interested in the general model used(i.e. does writers block
>readers and vice versa, etc) and more details like what files or

file

>structures are involved internaly by the Firebird.
>

Firebird keeps back versions of records that have been updated or
deleted, and
has a way to determine which version of a record a specific
transaction
should
see. Readers don't block writers and writers don't block readers.

Regards,

Ann



_____

Yahoo! Groups Links


* To visit your group on the web, go to:
http://groups.yahoo.com/group/firebird-support/

* To unsubscribe from this group, send an email to:
firebird-support-unsubscribe@yahoogroups.com
<mailto:firebird-support-unsubscribe@yahoogroups.com?subject=Unsubscribe>

* Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service <http://docs.yahoo.com/info/terms/> .




[Non-text portions of this message have been removed]