instead of only one.  This should speed up planning (only one hash path
to consider for a given pair of relations) as well as allow more effective
hashing, when there are multiple hashable joinclauses.

up code and documentation associated with Param nodes.

just done for copyfuncs/equalfuncs.  Read functions in particular get
a lot shorter than before, and it's much easier to compare an out function
with the corresponding read function to make sure they agree.
initdb forced due to small changes in nodestring format (regularizing
a few cases that were formerly idiosyncratic).

joinclauses is determined accurately for each join.  Formerly, the code only
considered joinclauses that used all of the rels from the outer side of the
join; thus for example
	FROM (a CROSS JOIN b) JOIN c ON (c.f1 = a.x AND c.f2 = b.y)
could not exploit a two-column index on c(f1,f2), since neither of the
qual clauses would be in the joininfo list it looked in.  The new code does
this correctly, and also is able to eliminate redundant clauses, thus fixing
the problem noted 24-Oct-02 by Hans-Jürgen Schönig.

Rod Taylor

before commit, not after :-( --- the original coding is not only unsafe
if an error occurs while it's processing, but it generates an invalid
sequence of WAL entries.  Resurrect 7.2 logic for deleting items when
no longer needed.  Use an enum instead of random macros.  Editorialize
on names used for routines and constants.  Teach backend/nodes routines
about new field in CreateTable struct.  Add a regression test.

hashed aggregation, but there's not yet planner support for it.

node now does its own grouping of the input rows, and has no need for a
preceding GROUP node in the plan pipeline.  This allows elimination of
the misnamed tuplePerGroup option for GROUP, and actually saves more code
in nodeGroup.c than it costs in nodeAgg.c, as well as being presumably
faster.  Restructure the API of query_planner so that we do not commit to
using a sorted or unsorted plan in query_planner; instead grouping_planner
makes the decision.  (Right now it isn't any smarter than query_planner
was, but that will change as soon as it has the option to select a hash-
based aggregation step.)  Despite all the hackery, no initdb needed since
only in-memory node types changed.

as per recent pghackers discussions.  initdb forced due to change in
fields of stored Query nodes.

columns, to allow more correct behavior in multiple-inheritance cases.
Patch by Alvaro Herrera, review by Tom Lane.

to be flexible about assignment casts without introducing ambiguity in
operator/function resolution.  Introduce a well-defined promotion hierarchy
for numeric datatypes (int2->int4->int8->numeric->float4->float8).
Change make_const to initially label numeric literals as int4, int8, or
numeric (never float8 anymore).
Explicitly mark Func and RelabelType nodes to indicate whether they came
from a function call, explicit cast, or implicit cast; use this to do
reverse-listing more accurately and without so many heuristics.
Explicit casts to char, varchar, bit, varbit will truncate or pad without
raising an error (the pre-7.2 behavior), while assigning to a column without
any explicit cast will still raise an error for wrong-length data like 7.3.
This more nearly follows the SQL spec than 7.2 behavior (we should be
reporting a 'completion condition' in the explicit-cast cases, but we have
no mechanism for that, so just do silent truncation).
Fix some problems with enforcement of typmod for array elements;
it didn't work at all in 'UPDATE ... SET array[n] = foo', for example.
Provide a generalized array_length_coerce() function to replace the
specialized per-array-type functions that used to be needed (and were
missing for NUMERIC as well as all the datetime types).
Add missing conversions int8<->float4, text<->numeric, oid<->int8.
initdb forced.

type for runtime constraint checks, instead of misusing the parse-time
Constraint node for the purpose.  Fix some damage introduced into type
coercion logic; in particular ensure that a coerced expression tree will
read out the correct result type when inspected (patch had broken some
RelabelType cases).  Enforce domain NOT NULL constraints against columns
that are omitted from an INSERT.

column additions, deletions, and renames that would let a child table
get out of sync with its parent.  Patch by Alvaro Herrera, with some
kibitzing by Tom Lane.

types, SRFs.  Not happy with memory management yet, but I'll commit these
other changes.

array header, and to compute sizing and alignment of array elements
the same way normal tuple access operations do --- viz, using the
tupmacs.h macros att_addlength and att_align.  This makes the world
safe for arrays of cstrings or intervals, and should make it much
easier to write array-type-polymorphic functions; as examples see
the cleanups of array_out and contrib/array_iterator.  By Joe Conway
and Tom Lane.

latent wrong-struct-type bugs and makes the coding style more uniform,
since the majority of places working with lists of column names were
already using Strings not Idents.  While at it, remove vestigial
support for Stream node type, and otherwise-unreferenced nodes.h entries
for T_TupleCount and T_BaseNode.
NB: full recompile is recommended due to changes of Node type numbers.
This shouldn't force an initdb though.

 > l.mode, l.isgranted from pg_lock_info() as l(relation oid, database oid,
 > backendpid int4, mode text, isgranted bool);
 > ERROR:  badly formatted planstring "COLUMNDEF "...
 >

Reported by Neil Conway -- I never implemented readfuncs.c support for
ColumnDef or TypeName, which is needed so that views can be created on
functions returning type RECORD. Here's a patch.

Joe Conway

types for Table Functions, as previously proposed on HACKERS. Here is a
brief explanation:

1. Creates a new pg_type typtype: 'p' for pseudo type (currently either
     'b' for base or 'c' for catalog, i.e. a class).

2. Creates new builtin type of typtype='p' named RECORD. This is the
     first of potentially several pseudo types.

3. Modify FROM clause grammer to accept:
     SELECT * FROM my_func() AS m(colname1 type1, colname2 type1, ...)
     where m is the table alias, colname1, etc are the column names, and
     type1, etc are the column types.

4. When typtype == 'p' and the function return type is RECORD, a list
     of column defs is required, and when typtype != 'p', it is
disallowed.

5. A check was added to ensure that the tupdesc provide via the parser
     and the actual return tupdesc match in number and type of
attributes.

When creating a function you can do:
     CREATE FUNCTION foo(text) RETURNS setof RECORD ...

When using it you can do:
     SELECT * from foo(sqlstmt) AS (f1 int, f2 text, f3 timestamp)
       or
     SELECT * from foo(sqlstmt) AS f(f1 int, f2 text, f3 timestamp)
       or
     SELECT * from foo(sqlstmt) f(f1 int, f2 text, f3 timestamp)

Included in the patches are adjustments to the regression test sql and
expected files, and documentation.

p.s.
     This potentially solves (or at least improves) the issue of builtin
     Table Functions. They can be bootstrapped as returning RECORD, and
     we can wrap system views around them with properly specified column
     defs. For example:

     CREATE VIEW pg_settings AS
       SELECT s.name, s.setting
       FROM show_all_settings()AS s(name text, setting text);

     Then we can also add the UPDATE RULE that I previously posted to
     pg_settings, and have pg_settings act like a virtual table, allowing
     settings to be queried and set.


Joe Conway

Implements between (symmetric / asymmetric) as a node.

Executes the left or right expression once, makes a Const out of the
resulting Datum and executes the >=, <= portions out of the Const sets.

Of course, the parser does a fair amount of preparatory work for this to
happen.

Rod Taylor

functionality.  Of note: dropping a table that has a SERIAL column
defined now drops the associated sequence automatically.

pg_relcheck is gone; CHECK, UNIQUE, PRIMARY KEY, and FOREIGN KEY
constraints all have real live entries in pg_constraint.  pg_depend
exists, and RESTRICT/CASCADE options work on most kinds of DROP;
however, pg_depend is not yet very well populated with dependencies.
(Most of the ones that are present at this point just replace formerly
hardwired associations, such as the implicit drop of a relation's pg_type
entry when the relation is dropped.)  Need to add more logic to create
dependency entries, improve pg_dump to dump constraints in place of
indexes and triggers, and add some regression tests.

Reused the Expr node to hold DISTINCT which strongly resembles
 the existing OP info. Define DISTINCT_EXPR which strongly resembles
 the existing OPER_EXPR opType, but with handling for NULLs required
 by SQL99.
We have explicit support for single-element DISTINCT comparisons
 all the way through to the executor. But, multi-element DISTINCTs
 are handled by expanding into a comparison tree in gram.y as is done for
 other row comparisons. Per discussions, it might be desirable to move
 this into one or more purpose-built nodes to be handled in the backend.
Define the optional ROW keyword and token per SQL99.
 This allows single-element row constructs, which were formerly disallowed
 due to shift/reduce conflicts with parenthesized a_expr clauses.
Define the SQL99 TREAT() function. Currently, use as a synonym for CAST().

returns-set boolean field in Func and Oper nodes.  This allows cleaner,
more reliable tests for expressions returning sets in the planner and
parser.  For example, a WHERE clause returning a set is now detected
and complained of in the parser, not only at runtime.

some kibitzing from Tom Lane.  Not everything works yet, and there's
no documentation or regression test, but let's commit this so Joe
doesn't need to cope with tracking changes in so many files ...

lists to join RTEs, attach a list of Vars and COALESCE expressions that will
replace the join's alias variables during planning.  This simplifies
flatten_join_alias_vars while still making it easy to fix up varno references
when transforming the query tree.  Add regression test cases for interactions
of subqueries with outer joins.

an 'opclass owner' column in pg_opclass.  Nothing is done with it at
present, but since there are plans to invent a CREATE OPERATOR CLASS
command soon, we'll probably want DROP OPERATOR CLASS too, which
suggests that a notion of ownership would be a good idea.

qualified operator names directly, for example CREATE OPERATOR myschema.+
( ... ).  To qualify an operator name in an expression you need to write
OPERATOR(myschema.+) (thanks to Peter for suggesting an escape hatch).
I also took advantage of having to reformat pg_operator to fix something
that'd been bugging me for a while: mergejoinable operators should have
explicit links to the associated cross-data-type comparison operators,
rather than hardwiring an assumption that they are named < and >.

entries, per pghackers discussion.  This fixes aggregates to live in
namespaces, and also simplifies/speeds up lookup in parse_func.c.
Also, add a 'proimplicit' flag to pg_proc that controls whether a type
coercion function may be invoked implicitly, or only explicitly.  The
current settings of these flags are more permissive than I would like,
but we will need to debate and refine the behavior; for now, I avoided
breaking regression tests as much as I could.

SELECT schema1.func2(...).  Aggregate names can be qualified at the
syntactic level, but the qualification is ignored for the moment.

in different namespaces.  Also, cleanup work on relation namespace
support: drop, alter, rename commands work for tables in non-default
namespaces.

addRangeTableEntry calls.  Remove relname field from RTEs, since
it will no longer be a useful unique identifier of relations;
we want to encourage people to rely on the relation OID instead.
Further work on dumping qual expressions in EXPLAIN, too.

the parsetree representation.  As yet we don't *do* anything with schema
names, just drop 'em on the floor; but you can enter schema-compatible
command syntax, and there's even a primitive CREATE SCHEMA command.
No doc updates yet, except to note that you can now extract a field
from a function-returning-row's result with (foo(...)).fieldname.

now has an RTE of its own, and references to its outputs now are Vars
referencing the JOIN RTE, rather than CASE-expressions.  This allows
reverse-listing in ruleutils.c to use the correct alias easily, rather
than painfully reverse-engineering the alias namespace as it used to do.
Also, nested FULL JOINs work correctly, because the result of the inner
joins are simple Vars that the planner can cope with.  This fixes a bug
reported a couple times now, notably by Tatsuo on 18-Nov-01.  The alias
Vars are expanded into COALESCE expressions where needed at the very end
of planning, rather than during parsing.
Also, beginnings of support for showing plan qualifier expressions in
EXPLAIN.  There are probably still cases that need work.
initdb forced due to change of stored-rule representation.

o  Change all current CVS messages of NOTICE to WARNING.  We were going
to do this just before 7.3 beta but it has to be done now, as you will
see below.

o Change current INFO messages that should be controlled by
client_min_messages to NOTICE.

o Force remaining INFO messages, like from EXPLAIN, VACUUM VERBOSE, etc.
to always go to the client.

o Remove INFO from the client_min_messages options and add NOTICE.

Seems we do need three non-ERROR elog levels to handle the various
behaviors we need for these messages.

Regression passed.

tests pass.

pgsql-hackers.  pg_opclass now has a row for each opclass supported by each
index AM, not a row for each opclass name.  This allows pg_opclass to show
directly whether an AM supports an opclass, and furthermore makes it possible
to store additional information about an opclass that might be AM-dependent.
pg_opclass and pg_amop now store "lossy" and "haskeytype" information that we
previously expected the user to remember to provide in CREATE INDEX commands.
Lossiness is no longer an index-level property, but is associated with the
use of a particular operator in a particular index opclass.

Along the way, IndexSupportInitialize now uses the syscaches to retrieve
pg_amop and pg_amproc entries.  I find this reduces backend launch time by
about ten percent, at the cost of a couple more special cases in catcache.c's
IndexScanOK.

Initial work by Oleg Bartunov and Teodor Sigaev, further hacking by Tom Lane.

initdb forced.