> > Will we still have readers-dont-block-writers behaviour?
>
> Sure. The only thing this really affects is VACUUM and
> schema-altering
> commands, which will now have to wait until reader
> transactions commit.
> In other words
>
> Session 1 Session 2
>
> BEGIN;
> SELECT * FROM foo;
>
> ALTER TABLE foo ...
>
> ...
>
> COMMIT;
>
> Session 2 will have to wait for session 1 to commit; before it didn't.
Not only, Tom -:)
Unfortunately, session 3 with just SELECT * FROM foo will also wait
for session 1 & session 2 commit.
Vadim