Subject Re: [IB-Architect] Super-transactions and Incremental Backup
Author Doug Chamberlin
At 6/20/00 12:11 PM (Tuesday), Jim Starkey wrote:
>Question 2: Garbage Collection
>I gather that the idea is to retain the newest pre-freeze point version of
>a record during garbage collection.

Most everything else Jim has describes reflects my understanding of Jason's
idea. However, the above statement (and every question which derives from
it) does not. I thought the idea was to retain all the at-freeze-point
records and the newest post-freeze-point records with any necessary garbage
collection allowed between them and pre-freeze point. Therefore, having
checkpointed the database at one freeze point and after garbage collection
has run on all records, the most number of versions of a record would be
two - the version that was committed at the time of the freeze and most
recent version resulting from any subsequent changes.

Where is the need for the most recent pre-freeze point version?