At 12:12 AM 2/14/2001 +0100, guido.klapperich@... wrote:

>Thanks, I think now I get it. One last question: is garbage collection the
>same
>as a sweep ?

No. A sweep includes a full garbage collection - every record in the
database is visited and cleaned if necessary. A sweep also resets the
OIT. It can because it has undone all the changes made by transactions
that didn't commit - so it can change their state to committed.

Garbage collection is an on-going process in the database. Every
time a transaction visits a record, it examines the records and does
any clean-up necessary. In the V6 superserver, the transaction
calls a special thread that just does garbage collection. In other
versions, the transaction makes the changes itself.


Regards,

Ann
www.ibphoenix.com
We have answers.