Re: Sequence Access Method WIP

On 3/4/16 11:09 PM, Petr Jelinek wrote:

> But first here is updated patch for sequence access methods. I went with
> the previously discussed custom type as this gives us proper control
> over the width of the state and making sure that it's not gonna be
> toastable, etc and we need this as sequence is limited to single page.
>
> Attached are 3 separate files. The first one (0001-create-am) is mainly
> separate for the reason that there is some overlap with Alexander's
> index access methods patch, so I extracted common code into separate
> patch as it will make it easier to merge in case we are lucky enough to
> get these patches in (but it's still based on Alexander's code). It
> provides infra for defining new access methods from SQL, although
> without the parser and without any actual access methods.
>
> The 0002-seqam provides the SQL interface and support for sequence
> access methods on top of the infra patch, and also provides all the
> sequence access methods infrastructure and abstraction and documentation.
>
> And finally the 0003-gapless-seq is example contrib module that
> implements dependably and transitionally safe gapless sequence access
> method. It's obviously slow as it has to do locking and basically
> serialize all the changes to sequence so only one transaction may use it
> at a time but it's truly gapless. It also serves as an example of use of
> the api and as a test.

As far as I can see Petr has addressed all the outstanding issues in
this patch and it's ready for a review. The patch applies with some
easily-fixed conflicts:

$ git apply -3 ../other/0002-seqam-2015-03-05.patch
error: patch failed: src/include/catalog/pg_proc.h:5225
Falling back to three-way merge...
Applied patch to 'src/include/catalog/pg_proc.h' with conflicts.

Simon, you are signed up to review. Do you have an idea of when you'll
be doing that?

--
-David
david(at)pgmasters(dot)net