Fix misspelling of disbursion to dispersion.

SQL92 semantics, including support for ALL option.  All three can be used
in subqueries and views.  DISTINCT and ORDER BY work now in views, too.
This rewrite fixes many problems with cross-datatype UNIONs and INSERT/SELECT
where the SELECT yields different datatypes than the INSERT needs.  I did
that by making UNION subqueries and SELECT in INSERT be treated like
subselects-in-FROM, thereby allowing an extra level of targetlist where the
datatype conversions can be inserted safely.
INITDB NEEDED!

(Don't forget that an alias is required.)  Views reimplemented as expanding
to subselect-in-FROM.  Grouping, aggregates, DISTINCT in views actually
work now (he says optimistically).  No UNION support in subselects/views
yet, but I have some ideas about that.  Rule-related permissions checking
moved out of rewriter and into executor.
INITDB REQUIRED!

ends to clean up (see my message of same date to pghackers), but mostly
it works.  INITDB REQUIRED!

for views. Views are now have a "relkind" of
RELKIND_VIEW instead of RELKIND_RELATION.

Also, views no longer have actual heap storage
files.

The following changes were made

1. CREATE VIEW sets the new relkind

2. The executor complains if a DELETE or
        INSERT references a view.

3. DROP RULE complains if an attempt is made
        to delete a view SELECT rule.

4. CREATE RULE "_RETmytable" AS ON SELECT TO mytable DO INSTEAD ...
        1. checks to make sure mytable is empty.
        2. sets the relkind to RELKIND_VIEW.
        3. deletes the heap storage files.
5. LOCK myview is not allowed. :)


6. the regression test type_sanity was changed to
        account for the new relkind value.

7. CREATE INDEX ON myview ... is not allowed.

8. VACUUM myview is not allowed.
        VACUUM automatically skips views when do the entire
        database.

9. TRUNCATE myview is not allowed.


THINGS LEFT TO THINK ABOUT

o pg_views

o pg_dump

o pgsql (\d \dv)
o Do we really want to be able to inherit from views?

o Is 'DROP TABLE myview' OK?

--
Mark Hollomon

user is now defined in terms of the user id, the user name is only computed
upon request (for display purposes). This is kind of the opposite of the
previous state, which would maintain the user name and compute the user id
for permission checks.

Besides perhaps saving a few cycles (integer vs string), this now creates a
single point of attack for changing the user id during a connection, for
purposes of "setuid" functions, etc.

to one another. Sort out builddir vs srcdir variable namings. Remove some
now obsoleted make variables.

Datum, not char*, for portability's sake.

for example, an SQL function can be used in a functional index.  (I make
no promises about speed, but it'll work ;-).)  Clean up and simplify
handling of functions returning sets.

right circumstances a hash join executed as a DECLARE CURSOR/FETCH
query would crash the backend.  Problem as seen in current sources was
that the hash tables were stored in a context that was a child of
TransactionCommandContext, which got zapped at completion of the FETCH
command --- but cursor cleanup executed at COMMIT expected the tables
to still be valid.  I haven't chased down the details as seen in 7.0.*
but I'm sure it's the same general problem.

pg_proc.c (where it's actually used).  Fix it to correctly handle tlists
that contain resjunk target items, and improve error messages.  This
addresses bug reported by Krupnikov 6-July-00.

right thing with variable-free clauses that contain noncachable functions,
such as 'WHERE random() < 0.5' --- these are evaluated once per
potential output tuple.  Expressions that contain only Params are
now candidates to be indexscan quals --- for example, 'var = ($1 + 1)'
can now be indexed.  Cope with RelabelType nodes atop potential indexscan
variables --- this oversight prevents 7.0.* from recognizing some
potentially indexscanable situations.

from Param nodes, per discussion a few days ago on pghackers.  Add new
expression node type FieldSelect that implements the functionality where
it's actually needed.  Clean up some other unused fields in Func nodes
as well.
NOTE: initdb forced due to change in stored expression trees for rules.

thing when there are multiple result relations.  Formerly, during
something like 'UPDATE foo*', foo's constraints and *only* foo's
constraints would be applied to all foo's children.  Wrong-o ...

These two routines will now ALWAYS elog() on failure, whether you ask for
a lock or not.  If you really want to get a NULL return on failure, call
the new routines heap_open_nofail()/heap_openr_nofail().  By my count there
are only about three places that actually want that behavior.  There were
rather more than three places that were missing the check they needed to
make under the old convention :-(.

if given a node type it doesn't support.  As is, wrong results from a
mergejoin would go undetected.

varlena elements work now.  Allow assignment to previously-nonexistent
subscript position to extend array, but only for 1-D arrays and only
if adjacent to existing positions (could do more if we had a way to
represent nulls in arrays, but I don't want to tackle that now).
Arrange for assignment of NULL to an array element in UPDATE to be a
no-op, rather than setting the entire array to NULL as it used to.
(Throwing an error would be a reasonable alternative, but it's never
done that...)  Update regress test accordingly.

Remove a bunch of crufty code for large-object-based arrays, which is
superseded by TOAST and likely hasn't worked in a long time anyway.
Clean up array code a little, and in particular eliminate its habit
of scribbling on the input array (ie, modifying the input tuple :-().

There's now only one transition value and transition function.
NULL handling in aggregates is a lot cleaner.  Also, use Numeric
accumulators instead of integer accumulators for sum/avg on integer
datatypes --- this avoids overflow at the cost of being a little slower.
Implement VARIANCE() and STDDEV() aggregates in the standard backend.

Also, enable new LIKE selectivity estimators by default.  Unrelated
change, but as long as I had to force initdb anyway...

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.

one of updating the whole text datatype, but there are so dang many
calls of these two routines that it seems worth a separate commit.

Special handling of TOAST relations during VACUUM. TOAST relations
are vacuumed while the lock on the master table is still active.
The ANALYZE flag doesn't propagate to their vacuuming because the
toaster access routines allways use index access ignoring stats, so
why compute them at all.

Protection of TOAST relations against normal INSERT/UPDATE/DELETE
while offering SELECT for debugging purposes.

Jan

and SELECT ... INTO ... too.

Jan

Don't go through pg_exec_query_dest(), but directly to the execution
routines.  Also, extend parameter lists so that there's no need to
change the global setting of allowSystemTableMods, a hack that was
certain to cause trouble in the event of any error.

for details).  It doesn't really do that much yet, since there are no
short-term memory contexts in the executor, but the infrastructure is
in place and long-term contexts are handled reasonably.  A few long-
standing bugs have been fixed, such as 'VACUUM; anything' in a single
query string crashing.  Also, out-of-memory is now considered a
recoverable ERROR, not FATAL.
Eliminate a large amount of crufty, now-dead code in and around
memory management.
Fix problem with holding off SIGTRAP, SIGSEGV, etc in postmaster and
backend startup.

are opened in a consistent order by different backends (I ordered them
by index OID because that's easy, but any other consistent order would
do as well).  This avoids potential deadlock for index types that we
acquire exclusive locks on ... ie, rtree.

materialized tupleset is small enough) instead of a temporary relation.
This was something I was thinking of doing anyway for performance, and Jan
says he needs it for TOAST because he doesn't want to cope with toasting
noname relations.  With this change, the 'noname table' support in heap.c
is dead code, and I have accordingly removed it.  Also clean up 'noname'
plan handling in planner --- nonames are either sort or materialize plans,
and it seems less confusing to handle them separately under those names.

discussion of 5/19/00).  pg_index is now searched for indexes of a
relation using an indexscan.  Moreover, this is done once and cached
in the relcache entry for the relation, in the form of a list of OIDs
for the indexes.  This list is used by the parser and executor to drive
lookups in the pg_index syscache when they want to know the properties
of the indexes.  Net result: index information will be fully cached
for repetitive operations such as inserts.

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

really worked.  Until now.

That means you can now set your options in either or all of $PGDATA/configuration,
some postmaster option (--enable-fsync=off), or set a SET command. The list of
options is in backend/utils/misc/guc.c, documentation will be written post haste.

pg_options is gone, so is that pq_geqo config file. Also removed were backend -K,
-Q, and -T options (no longer applicable, although -d0 does the same as -Q).

Added to configure an --enable-syslog option.

changed all callers from TPRINTF to elog(DEBUG)

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