pass-by-ref data types --- eg, an index on lower(textfield) --- no longer
leak memory during index creation or update.  Clean up a lot of redundant
code ... did you know that copy, vacuum, truncate, reindex, extend index,
and bootstrap each basically duplicated the main executor's logic for
extracting information about an index and preparing index entries?
Functional indexes should be a little faster now too, due to removal
of repeated function lookups.
CREATE INDEX 'opt_type' clause is deimplemented by these changes,
but I haven't removed it from the parser yet (need to merge with
Thomas' latest change set first).

memory contexts.  Currently, only leaks in expressions executed as
quals or projections are handled.  Clean up some old dead cruft in
executor while at it --- unused fields in state nodes, that sort of thing.

    WARNING: This is actually broken - we have self-deadlocks
	         due to concurrent changes in buffer management.
			 Vadim and me are working on it.

Jan

passing the index-is-unique flag to index build routines (duh! ...
why wasn't it done this way to begin with?).  Aside from eliminating
an eyesore, this should save a few milliseconds in btree index creation
because a full scan of pg_index is not needed any more.

--- ie, they're only called for side-effects.  Add a PG_RETURN_VOID()
macro and use it where appropriate.  This probably doesn't change the
machine code by a single bit ... it's just for documentation.

functions that take pass-by-value datatypes.  Should be ready for
port testing ...

fmgr_faddr() in favor of new-style calls.  Lots of cleanup of
sloppy casts to use XXXGetDatum and DatumGetXXX ...

running gcc and HP's cc with warnings cranked way up.  Signed vs unsigned
comparisons, routines declared static and then defined not-static,
that kind of thing.  Tedious, but perhaps useful...

from a constraint condition does not violate the constraint (cf. discussion
on pghackers 12/9/99).  Implemented by adding a parameter to ExecQual,
specifying whether to return TRUE or FALSE when the qual result is
really NULL in three-valued boolean logic.  Currently, ExecRelCheck is
the only caller that asks for TRUE, but if we find any other places that
have the wrong response to NULL, it'll be easy to fix them.

where necessary --- several of them didn't really need it, though.
tqual-checking macros simplified accordingly.

Fewer calls to nameout.

Better use of RelationGetRelationName.

* Buffer refcount cleanup (per my "progress report" to pghackers, 9/22).
* Add links to backend PROC structs to sinval's array of per-backend info,
and use these links for routines that need to check the state of all
backends (rather than the slow, complicated search of the ShmemIndex
hashtable that was used before).  Add databaseOID to PROC structs.
* Use this to implement an interlock that prevents DESTROY DATABASE of
a database containing running backends.  (It's a little tricky to prevent
a concurrently-starting backend from getting in there, since the new
backend is not able to lock anything at the time it tries to look up
its database in pg_database.  My solution is to recheck that the DB is
OK at the end of InitPostgres.  It may not be a 100% solution, but it's
a lot better than no interlock at all...)
* In ALTER TABLE RENAME, flush buffers for the relation before doing the
rename of the physical files, to ensure we don't get failures later from
mdblindwrt().
* Update TRUNCATE patch so that it actually compiles against current
sources :-(.
You should do "make clean all" after pulling these changes.

additional argument specifying the kind of lock to acquire/release (or
'NoLock' to do no lock processing).  Ensure that all relations are locked
with some appropriate lock level before being examined --- this ensures
that relevant shared-inval messages have been processed and should prevent
problems caused by concurrent VACUUM.  Fix several bugs having to do with
mismatched increment/decrement of relation ref count and mismatched
heap_open/close (which amounts to the same thing).  A bogus ref count on
a relation doesn't matter much *unless* a SI Inval message happens to
arrive at the wrong time, which is probably why we got away with this
sloppiness for so long.  Repair missing grab of AccessExclusiveLock in
DROP TABLE, ALTER/RENAME TABLE, etc, as noted by Hiroshi.
Recommend 'make clean all' after pulling this update; I modified the
Relation struct layout slightly.
Will post further discussion to pghackers list shortly.

real affect now.

New code for locking buffer' context.

Initial attempt to clean up the code...

Switch sprintf() to snprintf()
Remove any/all #if 0 -or- #ifdef NOT_USED -or- #ifdef FALSE sections of
	code

no longer returns buffer pointer, can be gotten from scan;
	descriptor; bootstrap can create multi-key indexes;
pg_procname index now is multi-key index; oidint2, oidint4, oidname
are gone (must be removed from regression tests); use System Cache
rather than sequential scan in many places; heap_modifytuple no
longer takes buffer parameter; remove unused buffer parameter in
a few other functions; oid8 is not index-able; remove some use of
single-character variable names; cleanup Buffer variables usage
and scan descriptor looping; cleaned up allocation and freeing of
tuples; 18k lines of diff;

Patch by: wieck@sapserv.debis.de (Jan Wieck)

   One  of  the design rules of PostgreSQL is extensibility. And
   to follow this rule means (at least for me) that there should
   not  only  be a builtin PL.  Instead I would prefer a defined
   interface for PL implemetations.