> Note: your link is wrong, corrected here:

Extra hyphen - sorry about and thanks for pointing it out!

> What the article is driving at is that postgres does not use rollback logs to 
> handle updated records in the MVCC implementation.  There are absolutely 
> performance tradeoffs in that decision and, if you do a lot of development 
> against postgresql, those tradeoffs should influence how you design 
> databases.  The author then cherry picked the 'worst case' case, large 
> unconstrained updates.

Hmm... I was wondering about that - even though he stressed that there
was (paraphrasing) no right or wrong - just different design
decisions!

> The article is a bit of a cheezy dig on postgres.  Another example is the 
> complaint about autonomous transactions with another cherry picked example to 
> make postgres look back. In the real world, these would not matter much, and 
> can be worked around (if you want to see my take on how to deal with it, see 
> here: https://github.com/leaselock/pgasync).

OK - so, I was wrong in my original assumption that somehow (and it
wasn't simply because of the phraseology - sweep vs vacuum) I thought
that PG and FB had a similar MVCC implementation vs. Oracle and MySQL
(InnoDB) (and OrioleDB). I'll do a deep dive into their docco and see
what they actually do! I'm actually very interested in the
benchmarking side of database technology - but I do know the old adage
- there are lies, damned lies, statistics and *_then_* there are
database benchmarks (as seen with the link I posted!).

Thanks for your input.

Best regards,


El!

> merlin


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