checkpoint in the bgwriter.  This forestalls overflow of the fsync request
queue, which is not fatal but causes considerable performance degradation
when it occurs (because backends then have to do their own fsyncs).  Per
patch from Itagaki Takahiro, modified a little bit by me.

a need for it back in the neolithic era, but it's certainly dead code in
any PG release we would recognize as such.  Since it forces an additional
network round trip to the backend, getting rid of it should provide some
small performance improvement for large-object-using clients.

was opening with INV_READ flag and then writing.  Prior to 8.1 the backend
did not reject this, but now it does.

them to use array_recv :-(.  Per report from Tim Kordas.

/etc/sysctl.conf.

Chris Campbell

1) rank_cd now use weight of lexemes
2) rank_cd and rank can use any combination of normalization methods:
        no normalization
        normalization by log(length of document)
        -----/------- by length of document
        -----/------- by number of unique word in document
        -----/------- by log(number of unique word in document)
        -----/------- by number of covers (only rank_cd)

Improve cover's search.

TODO: changes in documentation

> * Improve port/qsort() to handle sorts with 50% unique and 50% duplicate
>   value [qsort]
>
>   This involves choosing better pivot points for the quicksort.

then modified within the same transaction.  The code was using a linked list
of active PLpgSQL_expr structs, which was OK when it was written because
plpgsql never released any parse data structures for the life of the backend.
But since Neil fixed plpgsql's memory management, elements of the linked list
could be freed, leading to crash when the list is chased.  Per report and test
case from Kris Jurka.

make use of the recently added ability to create a shell type explicitly.

I also put in place some infrastructure to allow dump/no dump decisions
to be made separately for each database object, rather than the former
hardwired 'dump if in a dumpable schema' policy.  This was needed anyway
for shell types so now seemed a convenient time to do it.  The flexibility
isn't exposed to the user yet, but is ready for future extensions.

regression tests to account for the new error message wording. It seems
today is not my day...

Robert Treat

error messages I made yesterday -- thanks to Andrew Dunstan for reporting
this, and my apologies for missing it the first time.

are unnecessarily allocated on the heap rather than the stack. If the
StringInfo doesn't outlive the stack frame in which it is created,
there is no need to allocate it on the heap via makeStringInfo() --
stack allocation is faster.  While it's not a big deal unless the
code is in a critical path, I don't see a reason not to save a few
cycles -- using stack allocation is not less readable.

I also cleaned up a bit of code along the way: moved variable
declarations into a more tightly-enclosing scope where possible,
fixed some pointless copying of strings in dblink, etc.

more compliant with the error message style guide. In particular,
errdetail should begin with a capital letter and end with a period,
whereas errmsg should not. I also fixed a few related issues in
passing, such as fixing the repeated misspelling of "lexeme" in
contrib/tsearch2 (per Tom's suggestion).

creation of a shell type.  This allows a less hacky way of dealing with
the mutual dependency between a datatype and its I/O functions: make a
shell type, then make the functions, then define the datatype fully.
We should fix pg_dump to handle things this way, but this commit just deals
with the backend.

Martijn van Oosterhout, with some corrections by Tom Lane.

does not return None, per suggestion from Tom.

(I didn't use his patch, however). A void-returning PL/Python function
must return None (from Python), which is translated into a void datum
(and *not* NULL) for Postgres. I also added some regression tests for
this functionality.

* Split out libpq pgpass and environment documentation sections to make
  it easier for non-developers to find

backend version in C using > and < comparisons.

when the passed-down eflags indicate they can.
Simon Riggs and Tom Lane

bits indicating which optional capabilities can actually be exercised
at runtime.  This will allow Sort and Material nodes, and perhaps later
other nodes, to avoid unnecessary overhead in common cases.
This commit just adds the infrastructure and arranges to pass the correct
flag values down to plan nodes; none of the actual optimizations are here
yet.  I'm committing this separately in case anyone wants to measure the
added overhead.  (It should be negligible.)

Simon Riggs and Tom Lane

particular get rid of single quotes around language names and old WITH ()
construct.

by David Fetter

each tuple, as per my proposal of several days ago.  Also, clean up
sort memory management by keeping all working data in a separate memory
context, and refine the handling of low-memory conditions.

> * -Add 'tid != tid ' operator for use in corruption recovery