Re: 9.5 release notes

I've gone through the release notes and added comments referencing
commits as discussed earlier. Additionally I've improved and added a
bunch of items.

Further stuff that came up while looking:
* 2014-09-25 [b0d81ad] Heikki..: Add -D option to specify data directory to pg_c..
new options, should possibly be documented?

* 2014-10-02 [3acc10c9] Robert..: Increase the number of buffer mapping partition..
should we mention this? This has been patched by a number of
downstream vendors and users, so it's probably worth calling out?

* 2014-11-18 [606c012] Simon ..: Reduce btree scan overhead for < and > strategies
Worthy of a note in the performance section.

* 2014-11-22 [eca2b9b] Andrew..: Rework echo_hidden for \sf and \ef from commit ..
Seems far too minor in comparison to other stuff left out.

* 2014-11-07 [7516f52] Alvaro..: BRIN: Block Range Indexes
Looks to me like that should just be Alvaro.

* 2014-11-22 [b62f94c] Tom Lane: Allow simplification of EXISTS() subqueries con..
Planner change, I think it's good to mention those.

* 2014-11-28 [e384ed6] Tom Lane: Improve typcache: cache negative lookup results..
Should perhaps, together with other cache enhancing entries, be mentioned?

* 2014-12-08 [519b075] Simon ..: Use GetSystemTimeAsFileTime directly in win32
2014-12-08 [8001fe6] Simon ..: Windows: use GetSystemTimePreciseAsFileTime if ..
Timer resolution isn't a unimportant thing for people using explain?

* 2014-12-12 [7e354ab] Andrew..: Add several generator functions for jsonb that ..
2015-05-12 [c694701] Andrew..: Additional functions and operators for jsonb
2015-05-31 [37def42] Andrew..: Rename jsonb_replace to jsonb_set and allow it ..
2014-12-12 [237a882] Andrew..: Add json_strip_nulls and jsonb_strip_nulls fun..
should probably be merged? Similar set of authors and too many similar release note
entries.

* 2014-12-23 [d7ee82e] Alvaro..: Add SQL-callable pg_get_object_address
* 2014-12-30 [a676201] Alvaro..: Add pg_identify_object_as_address
should be merged.

* 2015-01-13 [4bad60e] Andres..: Allow latches to wait for socket writability wi..
2015-01-14 [59f71a0] Andres..: Add a default local latch for use in signal han..
2015-01-17 [ff44fba] Andres..: Replace walsender's latch with the general shar..
2015-02-03 [387da18] Andres..: Use a nonblocking socket for FE/BE communicatio..
2015-02-03 [4f85fde] Andres..: Introduce and use infrastructure for interrupt ..
2015-02-03 [4fe384b] Andres..: Process 'die' interrupts while reading/writing ..
2015-02-03 [6647248] Andres..: Don't allow immediate interrupts during authent..
2015-02-03 [6753333] Andres..: Move deadlock and other interrupt handling in p..
2015-02-13 [80788a4] Heikki..: Simplify waiting logic in reading from /writin..

* 2015-01-17 [9402869] Heikki..: Advance backend's advertised xmin more aggressi..
This is a pretty big efficiency boon for systems with longer
nontrivial transactions.

* 2015-01-29 [ed12700] Andres..: Align buffer descriptors to cache line boundari..
Maybe worthwhile to mention?

* 2015-02-16 [9e3ad1a] Tom Lane: Use fast path in plpgsql's RETURN/RETURN NEXT i..
2015-02-28 [e524cbd] Tom Lane: Track typmods in plpgsql expression evaluation ..
2015-03-04 [1345cc6] Tom Lane: Use standard casting mechanism to convert types..
2015-03-11 [21dcda2] Tom Lane: Allocate ParamListInfo once per plpgsql functio..

Maybe reformulate to generalize the array performance into plpgsql and
mention arrays and RETURN? And combine with the casting change entry,
because that's also about performance?

* 2015-02-20 [09d8d11] Tom Lane: Use FLEXIBLE_ARRAY_MEMBER in a bunch more places.
2015-02-20 [5740be6] Tom Lane: Some more FLEXIBLE_ARRAY_MEMBER hacking.
2015-02-20 [e38b1eb] Tom Lane: Use FLEXIBLE_ARRAY_MEMBER in struct varlena.
2015-02-20 [c110eff] Tom Lane: Use FLEXIBLE_ARRAY_MEMBER in struct RecordIOData.
2015-02-20 [33a3b03] Tom Lane: Use FLEXIBLE_ARRAY_MEMBER in some more places.
2015-02-20 [33b2a2c] Tom Lane: Fix statically allocated struct with FLEXIBLE_A..
2015-02-21 [f2874fe] Tom Lane: Some more FLEXIBLE_ARRAY_MEMBER fixes.
2015-02-21 [e1a11d9] Tom Lane: Use FLEXIBLE_ARRAY_MEMBER for HeapTupleHeaderDa..
2015-02-21 [2e21121] Tom Lane: Use FLEXIBLE_ARRAY_MEMBER in a number of other ..
Maybe add a note in the source code section? Not sure if relevant enough.

* 2015-02-21 [b419865] Jeff D..: In array_agg(), don't create a new context for ..
Peformance improvement?

* 2015-02-27 [f65e827] Tom Lane: Invent a memory context reset/delete callback m..
Interesting for devs, maybe add?

* 2015-03-11 [b557226] Tom Lane: Improve planner's cost estimation in the presen..
2015-03-03 [b989619] Tom Lane: Fix cost estimation for indexscans on expensive..
2015-03-11 [f4abd02] Tom Lane: Support flattening of empty-FROM subqueries and..
2015-05-04 [2503982] Tom Lane: Improve procost estimates for some text search ..
Mention? Notes about planner changes rather helpful when trying to pin
down performance regression.s

* 2015-03-18 [f9dead5] Alvaro..: Install shared libraries to bin/ in Windows und..
Shouldn't this be mentioned rather than unimportant stuff like

* 2015-03-23 [e5f455f] Tom Lane: Apply table and domain CHECK constraints in nam..
I think this should be dropped, it has essentially no consequence to users.

* 2015-03-24 [1d8198b] Bruce ..: Add support for ALTER TABLE IF EXISTS ... RENAM..
Should imo be wrapped together with the other IF EXISTS changes

* 2014-12-09 [ae4e688] Simon ..: Silence REINDEX
Doesn't seem to warrant a separate release note entry.

* 2015-05-19 [0b28ea7] Tom Lane: Avoid collation dependence in indexes of syste..
Doesn't seem to warrant a separate release note entry. We've left of
many more significant things.

* 2015-04-14 [9fa8b0e] Peter ..: Move pg_upgrade from contrib/ to src/bin/
2015-04-13 [81134af] Peter ..: Move pgbench from contrib/ to src/bin/
Should imo merged with all the other moved utilities.

* 2014-07-14 [91f03ba] Noah M..: MSVC: Recognize PGFILEDESC in contrib and conv..
2015-04-16 [22d0053] Alvaro..: MSVC: install src/test/modules together with c..
Don't seem to warrant a release note entry.

Greetings,

Andres Freund