Remaining 2017-03 CF entries

Hi,

When I started writing this, there were the following reamining CF
items, minus bugfix ones which aren't bound by the code freeze.

I think it makes sense to go through those and see whether it's
realistic to commit any of them.

Ready for Committer:

Add GUCs for predicate lock promotion thresholds:
- claimed by Kevin, should be easy enough

initdb configurable wal_segment_size
- parts have been committed
- significantly derailed by segment naming discussion
- possibly committable if we decide to skip the naming bit? But also a
bit late given that it touches some quite sensitive code.

Create fdw_outerpath for foreign
- haven't really followed discussion
- only marked as ready-for-committer 2017-04-04

Vacuum: allow usage of more than 1GB of work mem
- hm, maybe? Will take a look.

Unique Joins
- Tom's discussing things with David, not sure.

Push down more UPDATEs/DELETEs in postgres_fdw
- claimed by Robert?

postgres_fdw: support parameterized foreign joins
- think that depends on fdw_outerpath?

Waiting on Author:

SQL statements statistics counter view (pg_stat_sql)
- the code doesn't look quite ready
- don't think we quite have design agreement, e.g. I don't like where it's
hooked into query execution

Write Amplification Reduction Method (WARM)
- fair number of people don't think it's ready for v10.
- can't move to next fest because it's waiting-on-author, which doesn't
allow that. Doesn't strike me as a useful restriction.

BRIN optimize memory allocation
- I think Alvaro has indicated that he wants to take care of that?

Indexes with Included Columns (was Covering + unique indexes)
- Don't think concerns about #columns on truncated tuples have been
addressed. Should imo be returned-with-feedback.

Needs-Review:

Better estimate merging for duplicate vars in clausesel.c
- has been submitted pretty late (2017-02-24) and discussion is ongoing
- I'm inclined to punt on this one to the next release, previous
proposal along that line got some pushback

new plpgsql extra_checks
- Winner of the "most opaque CF title" award
- hasn't received a whole lot of review
- don't think we're even close to having design agreement

Generic type subscripting
- still some review back and forth
- probably should be punted

Any comments?

Greetings,

Andres