Change pg_bsd_indent to follow upstream rules for placement of comments
to the right of code, and remove pgindent hack that caused comments
following #endif to not obey the general rule.
Commit e3860ffa4d wasn't actually using
the published version of pg_bsd_indent, but a hacked-up version that
tried to minimize the amount of movement of comments to the right of
code. The situation of interest is where such a comment has to be
moved to the right of its default placement at column 33 because there's
code there. BSD indent has always moved right in units of tab stops
in such cases --- but in the previous incarnation, indent was working
in 8-space tab stops, while now it knows we use 4-space tabs. So the
net result is that in about half the cases, such comments are placed
one tab stop left of before. This is better all around: it leaves
more room on the line for comment text, and it means that in such
cases the comment uniformly starts at the next 4-space tab stop after
the code, rather than sometimes one and sometimes two tabs after.
Also, ensure that comments following #endif are indented the same
as comments following other preprocessor commands such as #else.
That inconsistency turns out to have been self-inflicted damage
from a poorly-thought-through post-indent "fixup" in pgindent.
This patch is much less interesting than the first round of indent
changes, but also bulkier, so I thought it best to separate the effects.
Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
Previously, we left such literals alone if the query or subquery had
no properties forcing a type decision to be made (such as an ORDER BY or
DISTINCT clause using that output column). This meant that "unknown" could
be an exposed output column type, which has never been a great idea because
it could result in strange failures later on. For example, an outer query
that tried to do any operations on an unknown-type subquery output would
generally fail with some weird error like "failed to find conversion
function from unknown to text" or "could not determine which collation to
use for string comparison". Also, if the case occurred in a CREATE VIEW's
query then the view would have an unknown-type column, causing similar
failures in queries trying to use the view.
To fix, at the tail end of parse analysis of a query, forcibly convert any
remaining "unknown" literals in its SELECT or RETURNING list to type text.
However, provide a switch to suppress that, and use it in the cases of
SELECT inside a set operation or INSERT command. In those cases we already
had type resolution rules that make use of context information from outside
the subquery proper, and we don't want to change that behavior.
Also, change creation of an unknown-type column in a relation from a
warning to a hard error. The error should be unreachable now in CREATE
VIEW or CREATE MATVIEW, but it's still possible to explicitly say "unknown"
in CREATE TABLE or CREATE (composite) TYPE. We want to forbid that because
it's nothing but a foot-gun.
This change creates a pg_upgrade failure case: a matview that contains an
unknown-type column can't be pg_upgraded, because reparsing the matview's
defining query will now decide that the column is of type text, which
doesn't match the cstring-like storage that the old materialized column
would actually have. Add a checking pass to detect that. While at it,
we can detect tables or composite types that would fail, essentially
for free. Those would fail safely anyway later on, but we might as
well fail earlier.
This patch is by me, but it owes something to previous investigations
by Rahila Syed. Also thanks to Ashutosh Bapat and Michael Paquier for
review.
Discussion: https://postgr.es/m/CAH2L28uwwbL9HUM-WR=hromW1Cvamkn7O-g8fPY2m=_7muJ0oA@mail.gmail.com
Previously, the right-hand side of a multiple-column assignment, if it
wasn't a sub-SELECT, had to be a simple parenthesized expression list,
because gram.y was responsible for "bursting" the construct into
independent column assignments. This had the minor defect that you
couldn't write ROW (though you should be able to, since the standard says
this is a row constructor), and the rather larger defect that unlike other
uses of row constructors, we would not expand a "foo.*" item into multiple
columns.
Fix that by changing the RHS to be just "a_expr" in the grammar, leaving
it to transformMultiAssignRef to separate the elements of a RowExpr;
which it will do only after performing standard transformation of the
RowExpr, so that "foo.*" behaves as expected.
The key reason we didn't do that before was the hard-wired handling of
DEFAULT tokens (SetToDefault nodes). This patch deals with that issue by
allowing DEFAULT in any a_expr and having parse analysis throw an error
if SetToDefault is found in an unexpected place. That's an improvement
anyway since the error can be more specific than just "syntax error".
The SQL standard suggests that the RHS could be any a_expr yielding a
suitable row value. This patch doesn't really move the goal posts in that
respect --- you're still limited to RowExpr or a sub-SELECT --- but it does
fix the grammar restriction, so it provides some tangible progress towards
a full implementation. And the limitation is now documented by an explicit
error message rather than an unhelpful "syntax error".
Discussion: <8542.1479742008@sss.pgh.pa.us>
Formerly we relied on checking after-the-fact to see if an expression
contained aggregates, window functions, or sub-selects when it shouldn't.
This is grotty, easily forgotten (indeed, we had forgotten to teach
DefineIndex about rejecting window functions), and none too efficient
since it requires extra traversals of the parse tree. To improve matters,
define an enum type that classifies all SQL sub-expressions, store it in
ParseState to show what kind of expression we are currently parsing, and
make transformAggregateCall, transformWindowFuncCall, and transformSubLink
check the expression type and throw error if the type indicates the
construct is disallowed. This allows removal of a large number of ad-hoc
checks scattered around the code base. The enum type is sufficiently
fine-grained that we can still produce error messages of at least the
same specificity as before.
Bringing these error checks together revealed that we'd been none too
consistent about phrasing of the error messages, so standardize the wording
a bit.
Also, rewrite checking of aggregate arguments so that it requires only one
traversal of the arguments, rather than up to three as before.
In passing, clean up some more comments left over from add_missing_from
support, and annotate some tests that I think are dead code now that that's
gone. (I didn't risk actually removing said dead code, though.)
Index expression columns are now named after the FigureColname result for
their expressions, rather than always being "pg_expression_N". Digits are
appended to this name if needed to make the column name unique within the
index. (That happens for regular columns too, thus fixing the old problem
that CREATE INDEX fooi ON foo (f1, f1) fails. Before exclusion indexes
there was no real reason to do such a thing, but now maybe there is.)
Default names for indexes and associated constraints now include the column
names of all their columns, not only the first one as in previous practice.
(Of course, this will be truncated as needed to fit in NAMEDATALEN. Also,
pkey indexes retain the historical behavior of not naming specific columns
at all.)
An example of the results:
regression=# create table foo (f1 int, f2 text,
regression(# exclude (f1 with =, lower(f2) with =));
NOTICE: CREATE TABLE / EXCLUDE will create implicit index "foo_f1_lower_exclusion" for table "foo"
CREATE TABLE
regression=# \d foo_f1_lower_exclusion
Index "public.foo_f1_lower_exclusion"
Column | Type | Definition
--------+---------+------------
f1 | integer | f1
lower | text | lower(f2)
btree, for table "public.foo"
(e.g. "INSERT ... VALUES (...), (...), ...") and elsewhere as allowed
by the spec. (e.g. similar to a FROM clause subselect). initdb required.
Joe Conway and Tom Lane.
will be expanded to a list of their member fields, rather than creating
a nested rowtype field as formerly. (The old behavior is still available
by omitting '.*'.) This syntax is not allowed by the SQL spec AFAICS,
so changing its behavior doesn't violate the spec. The new behavior is
substantially more useful since it allows, for example, triggers to check
for data changes with 'if row(new.*) is distinct from row(old.*)'. Per
my recent proposal.
Also performed an initial run through of upgrading our Copyright date to
extend to 2005 ... first run here was very simple ... change everything
where: grep 1996-2004 && the word 'Copyright' ... scanned through the
generated list with 'less' first, and after, to make sure that I only
picked up the right entries ...
the column by table OID and column number, if it's a simple column
reference. Along the way, get rid of reskey/reskeyop fields in Resdoms.
Turns out that representation was not convenient for either the planner
or the executor; we can make the planner deliver exactly what the
executor wants with no more effort.
initdb forced due to change in stored rule representation.
> =================================================================
> User interface proposal for multi-row function targetlist entries
> =================================================================
> 1. Only one targetlist entry may return a set.
> 2. Each targetlist item (other than the set returning one) is
> repeated for each item in the returned set.
>
Having gotten no objections (actually, no response at all), I can only
assume no one had heartburn with this change. The attached patch covers
the first of the two proposals, i.e. restricting the target list to only
one set returning function.
Joe Conway
> User interface proposal for multi-row function targetlist entries
> =================================================================
> 1. Only one targetlist entry may return a set.
> 2. Each targetlist item (other than the set returning one) is
> repeated for each item in the returned set.
>
Having gotten no objections (actually, no response at all), I can only assume
no one had heartburn with this change. The attached patch covers the first of
the two proposals, i.e. restricting the target list to only one set returning
function.
It compiles cleanly, and passes all regression tests. If there are no
objections, please apply.
Any suggestions on where this should be documented (other than maybe sql-select)?
Thanks,
Joe
p.s. Here's what the previous example now looks like:
CREATE TABLE bar(f1 int, f2 text, f3 int);
INSERT INTO bar VALUES(1, 'Hello', 42);
INSERT INTO bar VALUES(2, 'Happy', 45);
CREATE TABLE foo(a int, b text);
INSERT INTO foo VALUES(42, 'World');
INSERT INTO foo VALUES(42, 'Everyone');
INSERT INTO foo VALUES(45, 'Birthday');
INSERT INTO foo VALUES(45, 'New Year');
CREATE TABLE foo2(a int, b text);
INSERT INTO foo2 VALUES(42, '!!!!');
INSERT INTO foo2 VALUES(42, '????');
INSERT INTO foo2 VALUES(42, '####');
INSERT INTO foo2 VALUES(45, '$$$$');
CREATE OR REPLACE FUNCTION getfoo(int) RETURNS SETOF text AS '
SELECT b FROM foo WHERE a = $1
' language 'sql';
CREATE OR REPLACE FUNCTION getfoo2(int) RETURNS SETOF text AS '
SELECT b FROM foo2 WHERE a = $1
' language 'sql';
regression=# SELECT f1, f2, getfoo(f3) AS f4 FROM bar;
f1 | f2 | f4
----+-------+----------
1 | Hello | World
1 | Hello | Everyone
2 | Happy | Birthday
2 | Happy | New Year
(4 rows)
regression=# SELECT f1, f2, getfoo(f3) AS f4, getfoo2(f3) AS f5 FROM bar;
ERROR: Only one target list entry may return a set result
Joe Conway
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.
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.
of the SELECT part of the statement is just like a plain SELECT. All
INSERT-specific processing happens after the SELECT parsing is done.
This eliminates many problems, e.g. INSERT ... SELECT ... GROUP BY using
the wrong column labels. Ensure that DEFAULT clauses are coerced to
the target column type, whether or not stored clause produces the right
type. Substantial cleanup of parser's array support.
I have attached a patch to allow GROUP BY and/or ORDER BY function or
expressions. Note worthy items:
1. The expression or function need not be in the target list.
Example:
SELECT name FROM foo GROUP BY lower(name);
2. Simplified the grammar to use expressions only.
3. Cleaned up earlier patch in this area to make use of existing
utility functions.
3. Reduced some of the members in the SortGroupBy parse node. The
original data members were redundant with the new expression node.
(MUST do a "make clean" now)
4. Added a new parse node "JoinUsing". The JOIN USING clause was
overloading this SortGroupBy structure. With the afore mentioned
reduction of members, the two clauses lost all their commonality.
5. A bug still exist where, if a function or expression is GROUPed BY,
and an aggregate function does not include a attribute from the
expression or function, the backend crashes. (or something like
that) The bug pre-dates this patch. Example:
SELECT lower(a) AS lowcase, count(b) FROM foo GROUP BY lowcase;
*** BOOM ***
--Also when not in target list
SELECT count(b) FROM foo GROUP BY lower(a);
*** BOOM AGAIN ***
