Remove orphaned prototype

Rajeev rastogi
Revert C comment change in slot_attisnull()

Revert 89774b58b0ea2874765cae10c094bb6aaf707feb
Update comment.

generate_normalized_query() no longer needs to truncate text, but this
one comment didn't get the memo.  Per Peter Geoghegan.
Add pg_stat_archiver statistics view.

This view shows the statistics about the WAL archiver process's activity.

Gabriele Bartolini, reviewed by Michael Paquier, refactored a bit by me.
New json functions.

json_build_array() and json_build_object allow for the construction of
arbitrarily complex json trees. json_object() turns a one or two
dimensional array, or two separate arrays, into a json_object of
name/value pairs, similarly to the hstore() function.
json_object_agg() aggregates its two arguments into a single json object
as name value pairs.

Catalog version bumped.

Andrew Dunstan, reviewed by Marko Tiikkaja.
Add new make targets check-tests and installcheck-tests.

These do not run any specific schedule of tests, but only those
specified as part of the invocation, e.g.:

    make check-tests TESTS="json jsonb"
Minor docs fixes for new json functions.

Thom Brown.
Fix compiler warning in EXEC_BACKEND builds.

Per a report by Rajeev Rastogi.
Allow using huge TLB pages on Linux (MAP_HUGETLB)

This patch adds an option, huge_tlb_pages, which allows requesting the
shared memory segment to be allocated using huge pages, by using the
MAP_HUGETLB flag in mmap(). This can improve performance.

The default is 'try', which means that we will attempt using huge pages,
and fall back to non-huge pages if it doesn't work. Currently, only Linux
has MAP_HUGETLB. On other platforms, the default 'try' behaves the same as
'off'.

In the passing, don't try to round the mmap() size to a multiple of
pagesize. mmap() doesn't require that, and there's no particular reason for
PostgreSQL to do that either. When using MAP_HUGETLB, however, round the
request size up to nearest 2MB boundary. This is to work around a bug in
some Linux kernel versions, but also to avoid wasting memory, because the
kernel will round the size up anyway.

Many people were involved in writing this patch, including Christian Kruse,
Richard Poole, Abhijit Menon-Sen, reviewed by Peter Geoghegan, Andres Freund
and me.
Fix docs build.

Broken by the huge_tlb_pages patch.

Vik Fearing.
Remedy two small omissions in the new json functions docs.
Allow skipping some items in a multi-key GIN search.

In a multi-key search, ie. something like "col @> 'foo' AND col @> 'bar'",
as soon as we find the next item that matches the first criteria, we don't
need to check the second criteria for TIDs smaller the first match. That
saves a lot of effort, especially if one of the terms is rare, while the
second occurs very frequently.

Based on ideas from Alexander Korotkov's fast scan patch.
Further optimize multi-key GIN searches.

If we're skipping past a certain TID, avoid decoding posting list segments
that only contain smaller TIDs.

Extracted from Alexander Korotkov's fast scan patch, heavily modified.
Add more C comments to entab.c.
Add C functions to centralize entab processing
Fix pointer processing in new entab.c function
Further optimize GIN multi-key searches.

When skipping over some items in a posting tree, re-find the new location
by descending the tree from root, rather than walking the right links.
This can save a lot of I/O.

Heavily modified from Alexander Korotkov's fast scan patch.
Fix thinko in huge_tlb_pages patch.

We calculated the rounded-up size for the allocation, but then failed to
use the rounded-up value in the mmap() call. Oops.

Also, initialize allocsize, to silence warnings seen with some compilers,
as pointed out by Jeff Janes.
Add json_array_elements_text function.

This was a notable omission from the json functions added in 9.3 and
there have been numerous complaints about its absence.

Laurence Rowe.
Include planning time in EXPLAIN ANALYZE output.

This doesn't work for prepared queries, but it's not too easy to get
the information in that case and there's some debate as to exactly
what the right thing to measure is, so just do this for now.

Andreas Karlsson, with slight doc changes by me.