(table or index) before trying to open its relcache entry. This fixes
race conditions in which someone else commits a change to the relation's
catalog entries while we are in process of doing relcache load. Problems
of that ilk have been reported sporadically for years, but it was not
really practical to fix until recently --- for instance, the recent
addition of WAL-log support for in-place updates helped.
Along the way, remove pg_am.amconcurrent: all AMs are now expected to support
concurrent update.
- predefined variable "tps"
The value of variable tps is taken from the scaling factor
specified by -s option.
- -D option
Variable values can be defined by -D option.
- \set command now allows arithmetic calculations.
Update the calling convention for all external facing functions. By
external facing, I mean all functions that are directly referenced in
cube.sql. Prior to my update, all functions used the older V0 calling
convention. They now use V1.
New Functions:
cube(float[]), which makes a zero volume cube from a float array
cube(float[], float[]), which allows the user to create a cube from
two float arrays; one for the upper right and one for the lower left
coordinate.
cube_subset(cube, int4[]), to allow you to reorder or choose a subset of
dimensions from a cube, using index values specified in the array.
Joshua Reich
Few cleanups and couple of new things:
- add SHA2 algorithm to older OpenSSL
- add BIGNUM math to have public-key cryptography work on non-OpenSSL
build.
- gen_random_bytes() function
The status of SHA2 algoritms and public-key encryption can now be
changed to 'always available.'
That makes pgcrypto functionally complete and unless there will be new
editions of AES, SHA2 or OpenPGP standards, there is no major changes
planned.
- Replace sorted array of entries in maintenance_work_mem to binary tree,
this should improve create performance.
- More precisely calculate allocated memory, eliminate leaks
with user-defined extractValue()
- Improve wordings in tsearch2
This is an extension of pgstattuple to query information from indexes.
It supports btree, hash and gist. Gin is not supported. It scans only
index pages and does not read corresponding heap tuples. Therefore,
'dead_tuple' means the number of tuples with LP_DELETE flag.
Also, I added an experimental feature for btree indexes. It checks
fragmentation factor of indexes. If an leaf has the right link on the
next adjacent page in the file, it is assumed to be continuous (not
fragmented). It will help us to decide when to REINDEX.
ITAGAKI Takahiro
> Upstream confirmed my reply in the last mail in [1]: the complete
> escaping logic in DBMirror.pl is seriously screwew.
>
> [1] http://archives.postgresql.org/pgsql-bugs/2006-06/msg00065.php
I finally found some time to debug this, and I think I found a better
patch than the one you proposed. Mine is still hackish and is still a
workaround around a proper quoting solution, but at least it repairs
the parsing without introducing the \' quoting again.
I consider this a band-aid patch to fix the recent security update.
PostgreSQL gurus, would you consider applying this until a better
solution is found for DBMirror.pl?
Olivier, can you please confirm that the patch works for you, too?
Backpatched to 8.0.X.
Martin Pitt
* new split algorithm (as proposed in http://archives.postgresql.org/pgsql-hackers/2006-06/msg00254.php)
* possible call pickSplit() for second and below columns
* add spl_(l|r)datum_exists to GIST_SPLITVEC -
pickSplit should check its values to use already defined
spl_(l|r)datum for splitting. pickSplit should set
spl_(l|r)datum_exists to 'false' (if they was 'true') to
signal to caller about using spl_(l|r)datum.
* support for old pickSplit(): not very optimal
but correct split
* remove 'bytes' field from GISTENTRY: in any case size of
value is defined by it's type.
* split GIST_SPLITVEC to two structures: one for using in picksplit
and second - for internal use.
* some code refactoring
* support of subsplit to rtree opclasses
TODO: add support of subsplit to contrib modules
tuples with less header overhead than a regular HeapTuple, per my
recent proposal. Teach TupleTableSlot code how to deal with these.
As proof of concept, change tuplestore.c to store MinimalTuples instead
of HeapTuples. Future patches will expand the concept to other places
where it is useful.
initially be 0. This is needed as a previous ABORT might have wiped out
an automatically opened transaction without maintaining the cursor count.
- Fix regression test expected file for the correct ERROR message, which
we now get given the above bug fix.
used by OpenOffice. Dictionaries are placed at
http://lingucomponent.openoffice.org/spell_dic.html
Dictionary automatically recognizes format of files.
Warning. MySpell's format has limitation with compound
word support: it's impossible to mark affix as
compound-only affix. So for norwegian, german etc
languages it's recommended to use original ispell format.
For that reason I don't want to remove my2ispell
scripts, it's has workaround at least for norwegian language.
It required some changes in lexize algorithm, but interface with
dictionaries stays compatible with old dictionaries.
Funded by Georgia Public Library Service and LibLime, Inc.
versions of OpenSSL. If your OpenSSL does not contain SHA2, then there
should be no conflict. But ofcourse, if someone upgrades OpenSSL,
server starts crashing.
Backpatched to 8.1.X.
Marko Kreen
any use in the past many years, we'd have made some effort to include
them in all executor node types; but in fact they were only in
nodeAppend.c and nodeIndexscan.c, up until I copied nodeIndexscan.c's
occurrence into the new bitmap node types. Remove some other unused
macros in execdebug.h, too. Some day the whole header probably ought to
go away in favor of better-designed facilities.
pg_freespacemap_relations --- while one could theoretically get that
number by counting rows in pg_freespacemap_pages, it's surely the hard
way to do it. Avoid expensive and inconvenient conversion to and from
text format. Minor code and docs cleanup.
tracks index pages, not free space on pages):
1/ Index free bytes set to NULL
2/ Comment added to the README briefly mentioning the index business
3/ Columns reordered more logically
4/ 'Blockid' column removed
5/ Free bytes column renamed to just 'bytes' instead of 'blockfreebytes'
Mark Kirkwood
during parse analysis, not only errors detected in the flex/bison stages.
This is per my earlier proposal. This commit includes all the basic
infrastructure, but locations are only tracked and reported for errors
involving column references, function calls, and operators. More could
be done later but this seems like a good set to start with. I've also
moved the ReportSyntaxErrorPosition logic out of psql and into libpq,
which should make it available to more people --- even within psql this
is an improvement because warnings weren't handled by ReportSyntaxErrorPosition.
Most of the changes add the mandatory USING clause to DROP OPERATOR
CLASS statements. DROP TYPE is now DROP TYPE CASCADE; without
CASCADE a DROP TYPE fails due to the circular dependency on the
type's I/O functions. The DROP FUNCTION statements for the I/O
functions have been removed, as DROP TYPE CASCADE removes them
automatically. Patch from Michael Fuhr.
similar constants if they were not previously defined. All these
constants must be defined by limits.h according to C89, so we can
safely assume they are present.
(respectively) to rename yylex and related symbols. Some were doing
it this way already, while others used not-too-reliable sed hacks in
the Makefiles. It's all nice and consistent now.
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
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).
pgcrypto crypt()/md5 and hmac() leak memory when compiled against
OpenSSL as openssl.c digest ->reset will do two DigestInit calls
against a context. This happened to work with OpenSSL 0.9.6
but not with 0.9.7+.
Reason for the messy code was that I tried to avoid creating
wrapper structure to transport algorithm info and tried to use
OpenSSL context for it. The fix is to create wrapper structure.
It also uses newer digest API to avoid memory allocations
on reset with newer OpenSSLs.
Thanks to Daniel Blaisdell for reporting it.
sorry but fix can't be applyed to previous version: it's require
refill tsvector...
2 Small optimize of load time for huge dictionaries
3 use palloc instead of malloc during load dict file
singlebyte encodings, so we should have snowball for every encodings.
I hope that finalize multibyte support work in tsearch2, but testing is needed...
sizebitvec of tsearch2, as well as identical code in several other
contrib modules. This provided about a 20X speedup in building a
large tsearch2 index ... didn't try to measure its effects for other
operations. Thanks to Stephan Vollmer for providing a test case.
the data defining the semantics of a lock method (ie, conflict resolution
table and ancillary data, which is all constant) and the hash tables
storing the current state. The only thing we give up by this is the
ability to use separate hashtables for different lock methods, but there
is no need for that anyway. Put some extra fields into the LockMethod
definition structs to clean up some other uglinesses, like hard-wired
tests for DEFAULT_LOCKMETHOD and USER_LOCKMETHOD. This commit doesn't
do anything about the performance issues we were discussing, but it clears
away some of the underbrush that's in the way of fixing that.
support for the dbf2pg contrib module.
The submitter created a patch which replaces the silent ignoring of -F
(when iconv support is disabled) with a meaningful warning.
Martin Pitt
comment line where output as too long, and update typedefs for /lib
directory. Also fix case where identifiers were used as variable names
in the backend, but as typedefs in ecpg (favor the backend for
indenting).
Backpatch to 8.1.X.
- supports multibyte encodings
- more strict rules for lexemes
- flex isn't used
Add:
- tsquery plainto_tsquery(text)
Function makes tsquery from plain text.
- &&, ||, !! operation for tsquery for combining
tsquery from it's parts: 'foo & bar' || 'asd' => 'foo & bar | asd'
functionality, but I still need to make another pass looking at places
that incidentally use arrays (such as ACL manipulation) to make sure they
are null-safe. Contrib needs work too.
I have not changed the behaviors that are still under discussion about
array comparison and what to do with lower bounds.
1 Comparison operation for tsquery
2 Btree index on tsquery
3 numnode(tsquery) - returns 'length' of tsquery
4 tsquery @ tsquery, tsquery ~ tsquery - contains, contained for tsquery.
Note: They don't gurantee exact result, only MAY BE, so it
useful only for speed up rewrite functions
5 GiST index support for @,~
6 rewrite():
select rewrite(orig, what, to);
select rewrite(ARRAY[orig, what, to]) from tsquery_table;
select rewrite(orig, 'select what, to from tsquery_table;');
7 significantly improve cover algorithm
if there isn't one already open. Upon dblink_close, only commit
the open transaction if it was started by dblink_open, and only
then when all cursors opened by dblink_open are closed. The transaction
accounting is done individually for all named connections, plus
the persistent unnamed connection.
pointers, to ensure that compilers won't rearrange accesses to occur
while we're not holding the buffer header spinlock. It's probably
not necessary to mark volatile in every single place in bufmgr.c,
but better safe than sorry. Per trouble report from Kevin Grittner.
like '23:59:60' because of fractional-second roundoff problems. Trying
to control this upstream of the actual display code was hopeless; the right
way is to explicitly round fractional seconds in the display code and then
refigure the results if the fraction rounds up to 1. Per bug #1927.
Remove unportable use of tfind/tsearch in favor of bsearch. Fix up
random number generator to use random() not rand() and to actually honor
its min/max arguments properly. That wasn't so important before, but
with exposure of capability to ask for general ranges, it will be.
argument as a 'regclass' value instead of a text string. The frontend
conversion of text string to pg_class OID is now encapsulated as an
implicitly-invocable coercion from text to regclass. This provides
backwards compatibility to the old behavior when the sequence argument
is explicitly typed as 'text'. When the argument is just an unadorned
literal string, it will be taken as 'regclass', which means that the
stored representation will be an OID. This solves longstanding problems
with renaming sequences that are referenced in default expressions, as
well as new-in-8.1 problems with renaming such sequences' schemas or
moving them to another schema. All per recent discussion.
Along the way, fix some rather serious problems in dbmirror's support
for mirroring sequence operations (int4 vs int8 confusion for instance).
a few typos in comments.
The dictionaries I checked list "altho" as a variant of "although,"
but I didn't find any other instances of the former in the source
tree so I changed it.
Michael Fuhr
the pubkey functions a bit. The actual RSA-specific code
there is tiny, most of the patch consists of reorg of the
pubkey code, as lots of it was written as elgamal-only.
---------------------------------------------------------------------------
The SHLIB section was copy-pasted from somewhere and contains
several unnecessary libs. This cleans it up a bit.
-lcrypt
we don't use system crypt()
-lssl, -lssleay32
no SSL here
-lz in win32 section
already added on previous line
-ldes
The chance anybody has it is pretty low.
And the chance pgcrypto works with it is even lower.
Also trim the win32 section.
---------------------------------------------------------------------------
It is already disabled in Makefile, remove code too.
---------------------------------------------------------------------------
I was bit hasty making the random exponent 'k' a prime. Further researh
shows that Elgamal encryption has no specific needs in respect to k,
any random number is fine.
It is bit different for signing, there it needs to be 'relatively prime'
to p - 1, that means GCD(k, p-1) == 1, which is also a lot lighter than
full primality. As we don't do signing, this can be ignored.
This brings major speedup to Elgamal encryption.
---------------------------------------------------------------------------
o pgp_mpi_free: Accept NULLs
o pgp_mpi_cksum: result should be 16bit
o Remove function name from error messages - to be similar to other
SQL functions, and it does not match anyway the called function
o remove couple junk lines
---------------------------------------------------------------------------
o Support for RSA encryption
o Big reorg to better separate generic and algorithm-specific code.
o Regression tests for RSA.
---------------------------------------------------------------------------
o Tom stuck a CVS id into file. I doubt the usefulness of it,
but if it needs to be in the file then rather at the end.
Also tag it as comment for asciidoc.
o Mention bytea vs. text difference
o Couple clarifications
---------------------------------------------------------------------------
There is a choice whether to update it with pgp functions or
remove it. I decided to remove it, updating is pointless.
I've tried to keep the core of pgcrypto relatively independent
from main PostgreSQL, to make it easy to use externally if needed,
and that is good. Eg. that made development of PGP functions much
nicer.
But I have no plans to release it as generic library, so keeping such
doc
up-to-date is waste of time. If anyone is interested in using it in
other products, he can probably bother to read the source too.
Commented source is another thing - I'll try to make another pass
over code to see if there is anything non-obvious that would need
more comments.
---------------------------------------------------------------------------
Marko Kreen
calculations for interval and time/timetz to behave sanely for both
integer and float timestamps; up to now I think it's been doing
something pretty strange...
OpenSSL 0.9.6x. The DES functions use the older 'des_'
API, but the newer 3DES functions use the 0.9.7x-only
'DES_' API.
I think I just used /usr/include/openssl/des.h for reference
when implementing them, and had upgraded OpenSSL in the
meantime.
Following patch converts DES also to newer API and provides
compatibility functions for OpenSSL < 0.9.7.
I chose this route because:
- openssl.c uses few DES functions.
- compatibility for old 'des_' API is going away at some point
of time from OpenSSL.
- as seen from macros, new API is saner
- Thus pgcrypto supports any OpenSSL version from 0.9.5 to 1.0
Tested with OpenSSL 0.9.6c and 0.9.7e.
Marko Kreen
of password-based encryption from RFC2440 (OpenPGP).
The goal of this code is to be more featureful encryption solution
than current encrypt(), which only functionality is running cipher
over data.
Compared to encrypt(), pgp_encrypt() does following:
* It uses the equvialent of random Inital Vector to get cipher
into random state before it processes user data
* Stores SHA-1 of the data into result so any modification
will be detected.
* Remembers if data was text or binary - thus it can decrypt
to/from text data. This was a major nuisance for encrypt().
* Stores info about used algorithms with result, so user needs
not remember them - more user friendly!
* Uses String2Key algorithms (similar to crypt()) with random salt
to generate full-length binary key to be used for encrypting.
* Uses standard format for data - you can feed it to GnuPG, if needed.
Optional features (off by default):
* Can use separate session key - user data will be encrypted
with totally random key, which will be encrypted with S2K
generated key and attached to result.
* Data compression with zlib.
* Can convert between CRLF<->LF line-endings - to get fully
RFC2440-compliant behaviour. This is off by default as
pgcrypto does not know the line-endings of user data.
Interface is simple:
pgp_encrypt(data text, key text) returns bytea
pgp_decrypt(data text, key text) returns text
pgp_encrypt_bytea(data bytea, key text) returns bytea
pgp_decrypt_bytea(data bytea, key text) returns bytea
To change parameters (cipher, compression, mdc):
pgp_encrypt(data text, key text, parms text) returns bytea
pgp_decrypt(data text, key text, parms text) returns text
pgp_encrypt_bytea(data bytea, key text, parms text) returns bytea
pgp_decrypt_bytea(data bytea, key text, parms text) returns bytea
Parameter names I lifted from gpg:
pgp_encrypt('message', 'key', 'compress-algo=1,cipher-algo=aes256')
For text data, pgp_encrypt simply encrypts the PostgreSQL internal data.
This maps to RFC2440 data type 't' - 'extenally specified encoding'.
But this may cause problems if data is dumped and reloaded into database
which as different internal encoding. My next goal is to implement data
type 'u' - which means data is in UTF-8 encoding by converting internal
encoding to UTF-8 and back. And there wont be any compatibility
problems with current code, I think its ok to submit this without UTF-8
encoding by converting internal encoding to UTF-8 and back. And there
wont be any compatibility problems with current code, I think its ok to
submit this without UTF-8 support.
Here is v4 of PGP encrypt. This depends on previously sent
Fortuna-patch, as it uses the px_add_entropy function.
- New function: pgp_key_id() for finding key id's.
- Add SHA1 of user data and key into RNG pools. We need to get
randomness from somewhere, and it is in user best interests
to contribute.
- Regenerate pgp-armor test for SQL_ASCII database.
- Cleanup the key handling so that the pubkey support is less
hackish.
Marko Kreen
- Move openssl random provider to openssl.c and builtin provider
to internal.c
- Make px_random_bytes use Fortuna, instead of giving error.
- Retarget random.c to aquiring system randomness, for initial seeding
of Fortuna. There is ATM 2 functions for Windows,
reader from /dev/urandom and the regular time()/getpid() silliness.
Marko Kreen
functions as STRICT, and all functions except gen_salt() as IMMUTABLE.
gen_salt() is VOLATILE.
Although the functions are now STRICT, I left their PG_ARGISNULL()
checks in place as a protective measure for users who install the
new code but use old (non-STRICT) catalog entries (e.g., restored
from a dump). Per recent discussion in pgsql-hackers.
Patch from Michael Fuhr.
to make. We ship the table file in the tarball and so this dependency
just opens file timestamp skew problems without doing anything useful.
(Not that it should hurt, either ... except for cross-compile builds.)
chdir into PGDATA and subsequently use relative paths instead of absolute
paths to access all files under PGDATA. This seems to give a small
performance improvement, and it should make the system more robust
against naive DBAs doing things like moving a database directory that
has a live postmaster in it. Per recent discussion.
(currently in beta) when cryptolib = openssl. According to the
following checkin message from several years ago, OpenSSL application
developers should no longer rely on <openssl/evp.h> to include
everything they need:
http://cvs.openssl.org/chngview?cn=9888
This patch adds the necessary header files. It doesn't appear to
break anything when building against OpenSSL 0.9.7.
BTW, core appears to build and work fine with OpenSSL 0.9.8. I've
built 7.3 through HEAD against 0.9.8-beta6 without noticing any
problems.
Michael Fuhr
- Fix wrong index results on text, char, varchar for multibyte strings
- Fix some SIGFPE signals
- Add support for infinite timestamps
- Because of locale settings, btree_gist can not be a prefix index anymore (for text).
Each node holds now just the lower and upper boundary.
current time: provide a GetCurrentTimestamp() function that returns
current time in the form of a TimestampTz, instead of separate time_t
and microseconds fields. This is what all the callers really want
anyway, and it eliminates low-level dependencies on AbsoluteTime,
which is a deprecated datatype that will have to disappear eventually.
literally.
Add GUC variables:
"escape_string_warning" - warn about backslashes in non-E strings
"escape_string_syntax" - supports E'' syntax?
"standard_compliant_strings" - treats backslashes literally in ''
Update code to use E'' when escapes are used.
to the existing X-direction tests. An rtree class now includes 4 actual
2-D tests, 4 1-D X-direction tests, and 4 1-D Y-direction tests.
This involved adding four new Y-direction test operators for each of
box and polygon; I followed the PostGIS project's lead as to the names
of these operators.
NON BACKWARDS COMPATIBLE CHANGE: the poly_overleft (&<) and poly_overright
(&>) operators now have semantics comparable to box_overleft and box_overright.
This is necessary to make r-tree indexes work correctly on polygons.
Also, I changed circle_left and circle_right to agree with box_left and
box_right --- formerly they allowed the boundaries to touch. This isn't
actually essential given the lack of any r-tree opclass for circles, but
it seems best to sync all the definitions while we are at it.
polygon operators (<<, &<, >>, &>). Per ideas originally put forward
by andrew@supernews and later rediscovered by moi. This patch just
fixes the existing opclasses, and does not add any new behavior as I
proposed earlier; that can be sorted out later. In principle this
could be back-patched, since it changes only search behavior and not
system catalog entries nor rtree index contents. I'm not currently
planning to do that, though, since I think it could use more testing.
a physically separate type. Defining 'lo' as a domain over OID works
just fine and is more efficient. Improve documentation and fix up the
test script. (Would like to turn test script into a proper regression
test, but right now its output is not constant because of numeric OIDs;
plus it makes Unix-specific assumptions about files it can import.)
unlike template0 and template1 does not have any special status in
terms of backend functionality. However, all external utilities such
as createuser and createdb now connect to "postgres" instead of
template1, and the documentation is changed to encourage people to use
"postgres" instead of template1 as a play area. This should fix some
longstanding gotchas involving unexpected propagation of database
objects by createdb (when you used template1 without understanding
the implications), as well as ameliorating the problem that CREATE
DATABASE is unhappy if anyone else is connected to template1.
Patch by Dave Page, minor editing by Tom Lane. All per recent
pghackers discussions.
includes error checking and an appropriate ereport(ERROR) message.
This gets rid of rather tedious and error-prone manipulation of errno,
as well as a Windows-specific bug workaround, at more than a dozen
call sites. After an idea in a recent patch by Heikki Linnakangas.
it is sufficient to track whether a backend holds a lock or not, and
store information about transaction vs. session locks only in the
inside-the-backend LocalLockTable. Since there can now be but one
PROCLOCK per lock per backend, LockCountMyLocks() is no longer needed,
thus eliminating some O(N^2) behavior when a backend holds many locks.
Also simplify the LockAcquire/LockRelease API by passing just a
'sessionLock' boolean instead of a transaction ID. The previous API
was designed with the idea that per-transaction lock holding would be
important for subtransactions, but now that we have subtransactions we
know that this is unwanted. While at it, add an 'isTempObject' parameter
to LockAcquire to indicate whether the lock is being taken on a temp
table. This is not used just yet, but will be needed shortly for
two-phase commit.
and RelationNameGetTupleDesc() as deprecated; remove uses of the
latter in the contrib library. Along the way, clean up crosstab()
code and documentation a little.
are now reported via elog, eliminating the need to test the result code
at most call sites. Make it possible for the caller to distinguish a
freshly acquired lock from one already held in the current transaction.
Use that capability to avoid redundant AcceptInvalidationMessages() calls
in LockRelation().
spotted by Qingqing Zhou. The HASH_ENTER action now automatically
fails with elog(ERROR) on out-of-memory --- which incidentally lets
us eliminate duplicate error checks in quite a bunch of places. If
you really need the old return-NULL-on-out-of-memory behavior, you
can ask for HASH_ENTER_NULL. But there is now an Assert in that path
checking that you aren't hoping to get that behavior in a palloc-based
hash table.
Along the way, remove the old HASH_FIND_SAVE/HASH_REMOVE_SAVED actions,
which were not being used anywhere anymore, and were surely too ugly
and unsafe to want to see revived again.
Also, remove the rather useless return value of LockReleaseAll. Change
response to detection of corruption in the shared lock tables to PANIC,
since that is the only way of cleaning up fully.
Originally an idea of Heikki Linnakangas, variously hacked on by
Alvaro Herrera and Tom Lane.
for testing PLs and contrib_regression for testing contrib, instead of
overwriting the core system's regression database as formerly done.
Andrew Dunstan
external projects, we should be careful about what parts of the GiST
API are considered implementation details, and which are part of the
public API. Therefore, I've moved internal-only declarations into
gist_private.h -- future backward-incompatible changes to gist.h should
be made with care, to avoid needlessly breaking external GiST extensions.
Also did some related header cleanup: remove some unnecessary #includes
from gist.h, and remove some unused definitions: isAttByVal(), _gistdump(),
and GISTNStrategies.
