'scalar op ALL (array)', where the operator is applied between the
lefthand scalar and each element of the array. The operator must
yield boolean; the result of the construct is the OR or AND of the
per-element results, respectively.
Original coding by Joe Conway, after an idea of Peter's. Rewritten
by Tom to keep the implementation strictly separate from subqueries.
of an index can now be a computed expression instead of a simple variable.
Restrictions on expressions are the same as for predicates (only immutable
functions, no sub-selects). This fixes problems recently introduced with
inlining SQL functions, because the inlining transformation is applied to
both expression trees so the planner can still match them up. Along the
way, improve efficiency of handling index predicates (both predicates and
index expressions are now cached by the relcache) and fix 7.3 oversight
that didn't record dependencies of predicate expressions.
rewritten and the protocol is changed, but most elog calls are still
elog calls. Also, we need to contemplate mechanisms for controlling
all this functionality --- eg, how much stuff should appear in the
postmaster log? And what API should libpq expose for it?
expressions, ARRAY(sub-SELECT) expressions, some array functions.
Polymorphic functions using ANYARRAY/ANYELEMENT argument and return
types. Some regression tests in place, documentation is lacking.
Joe Conway, with some kibitzing from Tom Lane.
CHECK constraints.
There are apparently no other types of constraint in pg_constraint, so
now all bases are covered. Also, this patch assumes that consrc for a
CHECK constraint is always bracketed so that it's not necessary to add
extra brackets.
Christopher Kings-Lynne
startup, not in the parser; this allows ALTER DOMAIN to work correctly
with domain constraint operations stored in rules. Rod Taylor;
code review by Tom Lane.
Simplify SubLink by storing just a List of operator OIDs, instead of
a list of incomplete OpExprs --- that was a bizarre and bulky choice,
with no redeeming social value since we have to build new OpExprs
anyway when forming the plan tree.
'NOT (x IN (subselect))', that is 'NOT (x = ANY (subselect))',
rather than 'x <> ALL (subselect)' as we formerly did. This
opens the door to optimizing NOT IN the same way as IN, whereas
there's no hope of optimizing the expression using <>. Also,
convert 'x <> ALL (subselect)' to the NOT(IN) style, so that
the optimization will be available when processing rules dumped
by older Postgres versions.
initdb forced due to small change in SubLink node representation.
> The big problem is that while pg_dump's dump_trigger() looks at
> tginitdeferred and dumps accordingly, pg_get_constraintdef doesn't look
> at tginitdeferred, and therefore doesn't record the requirement as part
> of ALTER TABLE ADD CONSTRAINT.
pg_get_constraintdef should probably be looking at condeferrable and
condeferred in the pg_constraint row it's looking at. Maybe something
like the attached.
(Added, output only non-default values.)
Stephan Szabo
in the planned representation of a subplan at all any more, only SubPlan.
This means subselect.c doesn't scribble on its input anymore, which seems
like a good thing; and there are no longer three different possible
interpretations of a SubLink. Simplify node naming and improve comments
in primnodes.h. No change to stored rules, though.
so that all executable expression nodes inherit from a common supertype
Expr. This is somewhat of an exercise in code purity rather than any
real functional advance, but getting rid of the extra Oper or Func node
formerly used in each operator or function call should provide at least
a little space and speed improvement.
initdb forced by changes in stored-rules representation.
sublink results and COPY's domain constraint checking. A Const that
isn't really constant is just a Bad Idea(tm). Remove hacks in
parse_coerce and other places that were needed because of the former
klugery.
composite types. Add a couple more lsyscache.c routines to support this,
and make use of them in some other places that were doing lookups the
hard way.
ruleutils display is not such a great idea. For arguments of functions
and operators I think we'd better keep the historical behavior of showing
such casts explicitly, to ensure that the function/operator is reparsed
the same way when the rule is reloaded. This also makes the output of
EXPLAIN less obscurantist about exactly what's happening.
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.
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.
The -n and -N options were removed. Quoting is now smart enough to
supply quotes if and only if necessary.
Numerical types are now printed without quotes, except in cases of
special values such as NaN.
Boolean values printed as true and false.
Most string literals now do not escape whitespace characters (newlines,
etc.) for portability.
SET SESSION AUTHORIZATION argument is a string literal, to follow SQL.
Made commands output by pg_dump use consistent spacing and indentation.
sets of triggers. Also modify psql \d command to show foreign key
constraints as such and hide the triggers. pg_get_constraintdef()
function added to backend to support these. From Rod Taylor, code
review and some editorialization by Tom Lane.
to behave according to SQL92 (or according to my current understanding
of same, anyway). Per pghackers discussion way back in March 2002:
thread 'Do FROM items of different schemas conflict?'
extension to create binary compatible casts. Includes dependency tracking
as well.
pg_proc.proimplicit is now defunct, but will be removed in a separate
commit.
pg_dump provides a migration path from the previous scheme to declare
casts. Dumping binary compatible casts is currently impossible, though.
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
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().
GUC support. It's now possible to set datestyle, timezone, and
client_encoding from postgresql.conf and per-database or per-user
settings. Also, implement rollback of SET commands that occur in a
transaction that later fails. Create a SET LOCAL var = value syntax
that sets the variable only for the duration of the current transaction.
All per previous discussions in pghackers.
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 ...
in gram.y can make use of the keywords.c string table, instead of having
their own copies of the keyword strings. This saves a few kilobytes and
more importantly eliminates an opportunity for cut-and-paste errors.
per pghackers discussion. Add some more typsanity tests, and clean
up some problems exposed thereby (broken or missing array types for
some built-in types). Also, clean up loose ends from unknownin/out
patch.
DROP RULE and COMMENT ON RULE syntax adds an 'ON tablename' clause,
similar to TRIGGER syntaxes. To allow loading of existing pg_dump
files containing COMMENT ON RULE, the COMMENT code will still accept
the old syntax --- but only if the target rulename is unique across
the whole database.
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.
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.
Improve 'pg_internal.init' relcache entry preload mechanism so that it is
safe to use for all system catalogs, and arrange to preload a realistic
set of system-catalog entries instead of only the three nailed-in-cache
indexes that were formerly loaded this way. Fix mechanism for deleting
out-of-date pg_internal.init files: this must be synchronized with transaction
commit, not just done at random times within transactions. Drive it off
relcache invalidation mechanism so that no special-case tests are needed.
Cache additional information in relcache entries for indexes (their pg_index
tuples and index-operator OIDs) to eliminate repeated lookups. Also cache
index opclass info at the per-opclass level to avoid repeated lookups during
relcache load.
Generalize 'systable scan' utilities originally developed by Hiroshi,
move them into genam.c, use in a number of places where there was formerly
ugly code for choosing either heap or index scan. In particular this allows
simplification of the logic that prevents infinite recursion between syscache
and relcache during startup: we can easily switch to heapscans in relcache.c
when and where needed to avoid recursion, so IndexScanOK becomes simpler and
does not need any expensive initialization.
Eliminate useless opening of a heapscan data structure while doing an indexscan
(this saves an mdnblocks call and thus at least one kernel call).
per bug report from Stefan Hadjistoytchev. There are some cases
where the dot notation works, but there are more where it doesn't.
Eventually ought to consider fixing the parser to allow cases like
func().field, but for now this is the simplest patch.
it to suppress index opclass output for opclasses that are the default
for their datatype; only non-default opclasses are shown explicitly.
This is expected to improve portability of the CREATE INDEX command
across future versions of Postgres --- we've changed index opclasses
too often in the past to think we won't do so again.
has a DISTINCT ON clause, per bug report from Anthony Wood. While at it,
improve the DISTINCT-ON-clause recognizer routine to not be fooled by out-
of-order DISTINCT lists.
Note: I didn't force an initdb, figuring that one today was enough.
However, there is a new function in pg_proc.h, and pg_dump won't be
able to dump partial indexes until you add that function.
tests to return the correct results per SQL9x when given NULL inputs.
Reimplement these tests as well as IS [NOT] NULL to have their own
expression node types, instead of depending on special functions.
From Joe Conway, with a little help from Tom Lane.
lists should be reverse-compiled into targetlist index numbers, because
that's the only interpretation the parser allows for a constant in these
clauses. (Ergo, the only way they could have gotten into the list in
the first place is to have come from the targetlist; so this should always
work.) Per problem report from Peter E.
in Turkish locale. Keywords are now checked under pure ASCII case-folding
rules ('A'-'Z'->'a'-'z' and nothing else). However, once a word is
determined not to be a keyword, it will be case-folded under the current
locale, same as before. See pghackers discussion 20-Feb-01.
clause with an alias is a <subquery> and therefore hides table references
appearing within it, according to the spec. This is the same as the
preliminary patch I posted to pgsql-patches yesterday, plus some really
grotty code in ruleutils.c to reverse-list a query tree with the correct
alias name depending on context. I'd rather not have done that, but unless
we want to force another initdb for 7.1, there's no other way for now.
maintained for each cache entry. A cache entry will not be freed until
the matching ReleaseSysCache call has been executed. This eliminates
worries about cache entries getting dropped while still in use. See
my posting to pg-hackers of even date for more info.
ExecutorRun. This allows LIMIT to work in a view. Also, LIMIT in a
cursor declaration will behave in a reasonable fashion, whereas before
it was overridden by the FETCH count.
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!
complaints about ungrouped variables. This is for consistency with
behavior elsewhere, notably the fact that the relname is reported as
an alias in these same complaints. Also, it'll work with subselect-
in-FROM where old code didn't.
Here's the multibyte aware version of my patch to fix the truncation
of the rulename autogenerated during a CREATE VIEW. I've modified all
the places in the backend that want to construct the rulename to use
the MakeRetrieveViewRuleName(), where I put the #ifdef MULTIBYTE, so
that's the only place that knows how to construct a view rulename. Except
pg_dump, where I replicated the code, since it's a standalone binary.
The only effect the enduser will see is that views with names len(name)
> NAMEDATALEN-4 will fail to be created, if the derived rulename clases
with an existing rule: i.e. the user is trying to create two views with
long names whose first difference is past NAMEDATALEN-4 (but before
NAMEDATALEN: that'll error out after the viewname truncation.) In no
case will the user get left with a table without a view rule, as the
current code does.
Ross Reedstrom
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.
Tom Lane
Bruce Momjian
Peter Eisentraut
Thomas G. Lockhart
Jan Wieck