Re: Serializable Snapshot Isolation

Robert Haas <robertmhaas@gmail.com> wrote:
> I think the only changes we should make now are things that we're
> sure are improvements.
In that vein, anyone who is considering reviewing the patch should
check the latest from the git repo or request an incremental patch. 
I've committed a few things since the last patch post, but it
doesn't seem to make sense to repost the whole thing for them.  I
fixed a bug in the new shared memory list code, fixed a misleading
hint, and fixed some whitespace and comment issues.
The changes I've committed to the repo so far based on Heikki's
comments are, I feel, clear improvements.  It was actually fairly
embarrassing that I didn't notice some of that myself.
> based on reading the thread so far, we're off into the realm of
> speculating about trade-offs
This latest issue seems that way to me.  We're talking about
somewhere around 100 kB of shared memory in a 64 bit build with the
default number of connections, with a behavior on exhaustion which
matches what we do on normal locks.  This limit is easier to hit,
and we should probably revisit it, but I am eager to get the feature
as a whole in front of people, to see how well it works for them in
other respects.
I'll be quite surprised if we've found all the corner cases, but it
is working, and working well, in a variety of tests.  It has been
for months, really; I've been holding back, as requested, to avoid
distracting people from the 9.0 release.
-Kevin