Hello, Ann!

"Ann W. Harrison" wrote:

> If I understand, you want a transaction mode that will not interfere
> with garbage collection. Most of the work has been done make read-only
> read-committed transactions run as "pre-committed" so they don't affect
> garbage collection. Read-write read-committed transactions could be
> made not to affect the Oldest Active Transaction, but would require a
> different mechanism. OAT is what you care about, OIT doesn't affect
> garbage collection, only the number of transaction states every transaction
> must carry around.

anyway, READ UNCOMMITTED can be made simply by "unlocking" READ COMMITTED NO_RECORD_VERSION.
I mean this isolation level (read uncommitted) must show uncommitted record version
instead of "deadlock" message in read_committed_no_record_version mode.
Isn't it?
Extended work to make it independent from OIT/OAT/blat/etc can be done later.
Of course, if community really needs READ UNCOMMITTED isolation mode at all.

--
Dmitry Kuzmenko, Epsylon Technologies.