Daniel Vogelbacher wrote:

> In one of your last mails you wrote that sweep invokes GC.
> If I run a manual sweep every night, the select query
> should run fast, isn't it?
>

It might be more useful (and almost as effective) to run a
nightly backup. Backup also reads every record and removes
old record versions. Then run a sweep after the backup to
reset the oldest interested transaction id.

By the way, in an earlier message I said that only writers
perform garbage collection. I was either asleep, on drugs,
or confusing the strategies of other databases. In cooperative
garbage collection, every transaction that looks at a record
will remove old versions, readers as well as writers. And
removing old versions includes removing the stub created when
a record is deleted.

Cheers,

Ann