ruleutils.c blindly printed the user-given alias (or nothing if there
hadn't been one) for the target table of INSERT/UPDATE/DELETE queries.
That works a large percentage of the time, but not always: for queries
appearing in WITH, it's possible that we chose a different alias to
avoid conflict with outer-scope names. Since the chosen alias would
be used in any Var references to the target table, this'd lead to an
inconsistent printout with consequences such as dump/restore failures.
The correct logic for printing (or not) a relation alias was embedded
in get_from_clause_item. Factor it out to a separate function so that
we don't need a jointree node to use it. (Only a limited part of that
function can be reached from these new call sites, but this seems like
the cleanest non-duplicative factorization.)
In passing, I got rid of a redundant "\d+ rules_src" step in rules.sql.
Initial report from Jonathan Katz; thanks to Vignesh C for analysis.
This has been broken for a long time, so back-patch to all supported
branches.
Discussion: https://postgr.es/m/e947fa21-24b2-f922-375a-d4f763ef3e4b@postgresql.org
Discussion: https://postgr.es/m/CALDaNm1MMntjmT_NJGp-Z=xbF02qHGAyuSHfYHias3TqQbPF2w@mail.gmail.com
While on it, newlines are removed from the end of two elog() strings.
The others are simple grammar mistakes. One comment in pg_upgrade
referred incorrectly to sequences since a7e5457.
Author: Justin Pryzby
Discussion: https://postgr.es/m/20221230231257.GI1153@telsasoft.com
Backpatch-through: 11
Some options of these commands need to be able to identify the start
of the function body within the output of pg_get_functiondef().
It used to be that that always began with "AS", but since the
introduction of new-style SQL functions, it might also start with
"BEGIN" or "RETURN". Fix that on the psql side, and add some
regression tests.
Noted by me awhile ago, but I didn't do anything about it.
Thanks to David Johnston for a nag.
Discussion: https://postgr.es/m/AM9PR01MB8268D5CDABDF044EE9F42173FE8C9@AM9PR01MB8268.eurprd01.prod.exchangelabs.com
In commit 40c24bfef, I forgot to use get_rule_expr_paren() for the
arguments of AT TIME ZONE, resulting in possibly not printing parens
for expressions that need it. But get_rule_expr_paren() wouldn't have
gotten it right anyway, because isSimpleNode() hadn't been taught that
COERCE_SQL_SYNTAX parent nodes don't guarantee sufficient parentheses.
Improve all that. Also use this methodology for F_IS_NORMALIZED, so
that we don't print useless parens for that.
In passing, remove a comment that was obsoleted later.
Per report from Duncan Sands. Back-patch to v14 where this code
came in. (Before that, we didn't try to print AT TIME ZONE that way,
so there was no bug just ugliness.)
Discussion: https://postgr.es/m/f41566aa-a057-6628-4b7c-b48770ecb84a@deepbluecap.com
This switch impacts 9 patterns related to a SQL-mandated special syntax
for function calls:
- LOCALTIME [ ( typmod ) ]
- LOCALTIMESTAMP [ ( typmod ) ]
- CURRENT_TIME [ ( typmod ) ]
- CURRENT_TIMESTAMP [ ( typmod ) ]
- CURRENT_DATE
Five new entries are added to pg_proc to compensate the removal of
SQLValueFunction to provide backward-compatibility and making this
change transparent for the end-user (for example for the attribute
generated when a keyword is specified in a SELECT or in a FROM clause
without an alias, or when specifying something else than an Iconst to
the parser).
The parser included a set of checks coming from the files in charge of
holding the C functions used for the SQLValueFunction calls (as of
transformSQLValueFunction()), which are now moved within each function's
execution path, so this reduces the dependencies between the execution
and the parsing steps. As of this change, all the SQL keywords use the
same paths for their work, relying only on COERCE_SQL_SYNTAX. Like
fb32748, no performance difference has been noticed, while the perf
profiles get reduced with ExecEvalSQLValueFunction() gone.
Bump catalog version.
Reviewed-by: Corey Huinker, Ted Yu
Discussion: https://postgr.es/m/YzaG3MoryCguUOym@paquier.xyz
This commit changes six SQL keywords to use COERCE_SQL_SYNTAX rather
than relying on SQLValueFunction:
- CURRENT_ROLE
- CURRENT_USER
- USER
- SESSION_USER
- CURRENT_CATALOG
- CURRENT_SCHEMA
Among the six, "user", "current_role" and "current_catalog" require
specific SQL functions to allow ruleutils.c to map them to the SQL
keywords these require when using COERCE_SQL_SYNTAX. Having
pg_proc.proname match with the keyword ensures that the compatibility
remains the same when projecting any of these keywords in a FROM clause
to an attribute name when an alias is not specified. This is covered by
the tests added in 2e0d80c, making sure that a correct mapping happens
with each SQL keyword. The three others (current_schema, session_user
and current_user) already have pg_proc entries for this job, so this
brings more consistency between the way such keywords are treated in the
parser, the executor and ruleutils.c.
SQLValueFunction is reduced to half its contents after this change,
simplifying its logic a bit as there is no need to enforce a C collation
anymore for the entries returning a name as a result. I have made a few
performance tests, with a million-ish calls to these keywords without
seeing a difference in run-time or in perf profiles
(ExecEvalSQLValueFunction() is removed from the profiles). The
remaining SQLValueFunctions are now related to timestamps and dates.
Bump catalog version.
Reviewed-by: Corey Huinker
Discussion: https://postgr.es/m/YzaG3MoryCguUOym@paquier.xyz
Commit 1cc29fe7c, which taught EXPLAIN to print PARAM_EXEC Params as
the referenced expressions, included some checks to prevent matching
Params found in SubPlans or InitPlans to NestLoopParams of upper query
levels. At the time, this seemed possibly necessary to avoid false
matches because of the planner's habit of re-using the same PARAM_EXEC
slot in multiple places in a plan. Furthermore, in the absence of
LATERAL no such reference could be valid anyway. But it's possible
now that we have LATERAL, and in the wake of 46c508fbc and 1db5667ba
I believe the false-match hazard is gone. Hence, remove the
in_same_plan_level checks. As shown in the regression test changes,
this provides a useful improvement in readability for EXPLAIN of
LATERAL-using subplans.
Richard Guo, reviewed by Greg Stark and myself
Discussion: https://postgr.es/m/CAMbWs4-YSOcQXAagJetP95cAeZPqzOy5kM5yijG0PVW5ztRb4w@mail.gmail.com
If the non-recursive term of a SEARCH BREADTH FIRST recursive
query has only constants in its target list, the planner will
fold the starting RowExpr added by rewrite into a simple Const
of type RECORD. The executor doesn't have any problem with
that --- but EXPLAIN VERBOSE will encounter the Const as the
ultimate source of truth about what the field names of the
SET column are, and it didn't know what to do with that.
Fortunately, we can pull the identifying typmod out of the
Const, in much the same way that record_out would.
For reasons that remain a bit obscure to me, this only fails
with SEARCH BREADTH FIRST, not SEARCH DEPTH FIRST or CYCLE.
But I added regression test cases for both of those options
too, just to make sure we don't break it in future.
Per bug #17644 from Matthijs van der Vleuten. Back-patch
to v14 where these constructs were added.
Discussion: https://postgr.es/m/17644-3bd1f3036d6d7a16@postgresql.org
In a similar effort to f01592f91, here we mostly rename shadowed local
variables to remove the warnings produced when compiling with
-Wshadow=compatible-local.
This fixes 63 warnings and leaves just 5.
Author: Justin Pryzby, David Rowley
Reviewed-by: Justin Pryzby
Discussion https://postgr.es/m/20220817145434.GC26426%40telsasoft.com
SYSTEM_USER is a reserved keyword of the SQL specification that,
roughly described, is aimed at reporting some information about the
system user who has connected to the database server. It may include
implementation-specific information about the means by the user
connected, like an authentication method.
This commit implements SYSTEM_USER as of auth_method:identity, where
"auth_method" is a keyword about the authentication method used to log
into the server (like peer, md5, scram-sha-256, gss, etc.) and
"identity" is the authentication identity as introduced by 9afffcb (peer
sets authn to the OS user name, gss to the user principal, etc.). This
format has been suggested by Tom Lane.
Note that thanks to d951052, SYSTEM_USER is available to parallel
workers.
Bump catalog version.
Author: Bertrand Drouvot
Reviewed-by: Jacob Champion, Joe Conway, Álvaro Herrera, Michael Paquier
Discussion: https://postgr.es/m/7e692b8c-0b11-45db-1cad-3afc5b57409f@amazon.com
In a similar effort to f736e188c and 110d81728, fixup various usages of
string functions where a more appropriate function is available and more
fit for purpose.
These changes include:
1. Use cstring_to_text_with_len() instead of cstring_to_text() when
working with a StringInfoData and the length can easily be obtained.
2. Use appendStringInfoString() instead of appendStringInfo() when no
formatting is required.
3. Use pstrdup(...) instead of psprintf("%s", ...)
4. Use pstrdup(...) instead of psprintf(...) (with no formatting)
5. Use appendPQExpBufferChar() instead of appendPQExpBufferStr() when the
length of the string being appended is 1.
6. appendStringInfoChar() instead of appendStringInfo() when no formatting
is required and string is 1 char long.
7. Use appendPQExpBufferStr(b, .) instead of appendPQExpBuffer(b, "%s", .)
8. Don't use pstrdup when it's fine to just point to the string constant.
I (David) did find other cases of #8 but opted to use #4 instead as I
wasn't certain enough that applying #8 was ok (e.g in hba.c)
Author: Ranier Vilela, David Rowley
Discussion: https://postgr.es/m/CAApHDvo2j2+RJBGhNtUz6BxabWWh2Jx16wMUMWKUjv70Ver1vg@mail.gmail.com
The reverts the following and makes some associated cleanups:
commit f79b803dc: Common SQL/JSON clauses
commit f4fb45d15: SQL/JSON constructors
commit 5f0adec25: Make STRING an unreserved_keyword.
commit 33a377608: IS JSON predicate
commit 1a36bc9db: SQL/JSON query functions
commit 606948b05: SQL JSON functions
commit 49082c2cc: RETURNING clause for JSON() and JSON_SCALAR()
commit 4e34747c8: JSON_TABLE
commit fadb48b00: PLAN clauses for JSON_TABLE
commit 2ef6f11b0: Reduce running time of jsonb_sqljson test
commit 14d3f24fa: Further improve jsonb_sqljson parallel test
commit a6baa4bad: Documentation for SQL/JSON features
commit b46bcf7a4: Improve readability of SQL/JSON documentation.
commit 112fdb352: Fix finalization for json_objectagg and friends
commit fcdb35c32: Fix transformJsonBehavior
commit 4cd8717af: Improve a couple of sql/json error messages
commit f7a605f63: Small cleanups in SQL/JSON code
commit 9c3d25e17: Fix JSON_OBJECTAGG uniquefying bug
commit a79153b7a: Claim SQL standard compliance for SQL/JSON features
commit a1e7616d6: Rework SQL/JSON documentation
commit 8d9f9634e: Fix errors in copyfuncs/equalfuncs support for JSON node types.
commit 3c633f32b: Only allow returning string types or bytea from json_serialize
commit 67b26703b: expression eval: Fix EEOP_JSON_CONSTRUCTOR and EEOP_JSONEXPR size.
The release notes are also adjusted.
Backpatch to release 15.
Discussion: https://postgr.es/m/40d2c882-bcac-19a9-754d-4299e1d87ac7@postgresql.org
In a similar effort to f01592f91, here we're targetting fixing the
warnings where we've deemed the shadowing variable to serve a close enough
purpose to the shadowed variable just to reuse the shadowed version and
not declare the shadowing variable at all.
By my count, this takes the warning count from 106 down to 71.
Author: Justin Pryzby
Discussion: https://postgr.es/m/20220825020839.GT2342@telsasoft.com
These should have been included in 421892a19 as these shadowed variable
warnings can also be fixed by adjusting the scope of the shadowed variable
to put the declaration for it in an inner scope.
This is part of the same effort as f01592f91.
By my count, this takes the warning count from 114 down to 106.
Author: David Rowley and Justin Pryzby
Discussion: https://postgr.es/m/CAApHDvrwLGBP%2BYw9vriayyf%3DXR4uPWP5jr6cQhP9au_kaDUhbA%40mail.gmail.com
The standard way to check for list emptiness is to compare the
List pointer to NIL; our list code goes out of its way to ensure
that that is the only representation of an empty list. (An
acceptable alternative is a plain boolean test for non-null
pointer, but explicit mention of NIL is usually preferable.)
Various places didn't get that memo and expressed the condition
with list_length(), which might not be so bad except that there
were such a variety of ways to check it exactly: equal to zero,
less than or equal to zero, less than one, yadda yadda. In the
name of code readability, let's standardize all those spellings
as "list == NIL" or "list != NIL". (There's probably some
microscopic efficiency gain too, though few of these look to be
at all performance-critical.)
A very small number of cases were left as-is because they seemed
more consistent with other adjacent list_length tests that way.
Peter Smith, with bikeshedding from a number of us
Discussion: https://postgr.es/m/CAHut+PtQYe+ENX5KrONMfugf0q6NHg4hR5dAhqEXEc2eefFeig@mail.gmail.com
The dependency logic failed to register a column-level dependency
when a view or rule contains a reference to a specific column of
the result of a function-returning-composite. That meant you could
drop the column from the composite type, causing trouble for future
executions of the view. We've known about this for years, but never
summoned the energy to actually fix it, instead installing various
low-level defenses to prevent crashing on references to dropped columns.
We had to do that to plug the hole in stable branches, where there might
be pre-existing broken references; but let's fix the root cause today.
To do that, add some logic (borrowed from get_rte_attribute_is_dropped)
to find_expr_references_walker, to check whether a Var referencing an
RTE_FUNCTION RTE is referencing a column of a composite type, and if
so add the proper dependency.
However ... it seems mighty unwise to remove said low-level defenses,
since there could be other bugs now or in the future that allow
reaching them. By the same token, letting those defenses go untested
seems unwise. Hence, rather than just dropping the associated test
cases, hack them to continue working by the expedient of manually
dropping the pg_depend entries that this fix installs.
Back-patch into v15. I don't want to risk changing this behavior
in stable branches, but it seems not too late for v15. (Since
we have already forced initdb for beta3, we can be sure that all
production v15 installations will have these added dependencies.)
Discussion: https://postgr.es/m/182492.1658431155@sss.pgh.pa.us
Due to lack of concern for the case in the dependency code, it's
possible to drop a column of a composite type even though stored
queries have references to the dropped column via functions-in-FROM
that return the composite type. There are "soft" references,
namely FROM-clause aliases for such columns, and "hard" references,
that is actual Vars referring to them. The right fix for hard
references is to add dependencies preventing the drop; something
we've known for many years and not done (and this commit still doesn't
address it). A "soft" reference shouldn't prevent a drop though.
We've been around on this before (cf. 9b35ddce9, 2c4debbd0), but
nobody had noticed that the current behavior can result in dump/reload
failures, because ruleutils.c can print more column aliases than the
underlying composite type now has. So we need to rejigger the
column-alias-handling code to treat such columns as dropped and not
print aliases for them.
Rather than writing new code for this, I used expandRTE() which already
knows how to figure out which function result columns are dropped.
I'd initially thought maybe we could use expandRTE() in all cases, but
that fails for EXPLAIN's purposes, because the planner strips a lot of
RTE infrastructure that expandRTE() needs. So this patch just uses it
for unplanned function RTEs and otherwise does things the old way.
If there is a hard reference (Var), then removing the column alias
causes us to fail to print the Var, since there's no longer a name
to print. Failing seems less desirable than printing a made-up
name, so I made it print "?dropped?column?" instead.
Per report from Timo Stolz. Back-patch to all supported branches.
Discussion: https://postgr.es/m/5c91267e-3b6d-5795-189c-d15a55d61dbb@nullachtvierzehn.de
This allows aliases for sub-SELECTs and VALUES clauses in the FROM
clause to be omitted.
This is an extension of the SQL standard, supported by some other
database systems, and so eases the transition from such systems, as
well as removing the minor inconvenience caused by requiring these
aliases.
Patch by me, reviewed by Tom Lane.
Discussion: https://postgr.es/m/CAEZATCUCGCf82=hxd9N5n6xGHPyYpQnxW8HneeH+uP7yNALkWA@mail.gmail.com
There were many calls to construct_array() and deconstruct_array() for
built-in types, for example, when dealing with system catalog columns.
These all hardcoded the type attributes necessary to pass to these
functions.
To simplify this a bit, add construct_array_builtin(),
deconstruct_array_builtin() as wrappers that centralize this hardcoded
knowledge. This simplifies many call sites and reduces the amount of
hardcoded stuff that is spread around.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/2914356f-9e5f-8c59-2995-5997fc48bcba%40enterprisedb.com
ruleutils.c was coded to suppress the AS label for a SELECT output
expression if the column name is "?column?", which is the parser's
fallback if it can't think of something better. This is fine, and
avoids ugly clutter, so long as (1) nothing further up in the parse
tree relies on that column name or (2) the same fallback would be
assigned when the rule or view definition is reloaded. Unfortunately
(2) is far from certain, both because ruleutils.c might print the
expression in a different form from how it was originally written
and because FigureColname's rules might change in future releases.
So we shouldn't rely on that.
Detecting exactly whether there is any outer-level use of a SELECT
column name would be rather expensive. This patch takes the simpler
approach of just passing down a flag indicating whether there *could*
be any outer use; for example, the output column names of a SubLink
are not referenceable, and we also do not care about the names exposed
by the right-hand side of a setop. This is sufficient to suppress
unwanted clutter in all but one case in the regression tests. That
seems like reasonable evidence that it won't be too much in users'
faces, while still fixing the cases we need to fix.
Per bug #17486 from Nicolas Lutic. This issue is ancient, so
back-patch to all supported branches.
Discussion: https://postgr.es/m/17486-1ad6fd786728b8af@postgresql.org
I started out with the intention to rename value_type to item_type to
avoid a collision with a typedef name that appears on some platforms.
Along the way, I noticed that the adjacent field "format" was not being
correctly handled by the backend/nodes/ infrastructure functions:
copyfuncs.c erroneously treated it as a scalar, while equalfuncs,
outfuncs, and readfuncs omitted handling it at all. This looks like
it might be cosmetic at the moment because the field is always NULL
after parse analysis; but that's likely a bug in itself, and the code's
certainly not very future-proof. Let's fix it while we can still do so
without forcing an initdb on beta testers.
Further study found a few other inconsistencies in the backend/nodes/
infrastructure for the recently-added JSON node types, so fix those too.
catversion bumped because of potential change in stored rules.
Discussion: https://postgr.es/m/526703.1652385613@sss.pgh.pa.us
Coverity complains that dpns->outer_plan is deferenced (to obtain
->targetlist) when possibly NULL. We can avoid this by using
dpns->outer_tlist instead, which was already obtained a few lines up.
The fact that we end up with
dpns->inner_tlist = dpns->outer_tlist
is a bit suspicious-looking and maybe worthy of more investigation, but
I'll leave that for another day.
Reviewed-by: Michaël Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/202204191345.qerjy3kxi3eb@alvherre.pgsql
These clauses allow the user to specify how data from nested paths are
joined, allowing considerable freedom in shaping the tabular output of
JSON_TABLE.
PLAN DEFAULT allows the user to specify the global strategies when
dealing with sibling or child nested paths. The is often sufficient to
achieve the necessary goal, and is considerably simpler than the full
PLAN clause, which allows the user to specify the strategy to be used
for each named nested path.
Nikita Glukhov
Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zhihong Yu,
Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby.
Discussion: https://postgr.es/m/7e2cb85d-24cf-4abb-30a5-1a33715959bd@postgrespro.ru
This feature allows jsonb data to be treated as a table and thus used in
a FROM clause like other tabular data. Data can be selected from the
jsonb using jsonpath expressions, and hoisted out of nested structures
in the jsonb to form multiple rows, more or less like an outer join.
Nikita Glukhov
Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zhihong Yu (whose
name I previously misspelled), Himanshu Upadhyaya, Daniel Gustafsson,
Justin Pryzby.
Discussion: https://postgr.es/m/7e2cb85d-24cf-4abb-30a5-1a33715959bd@postgrespro.ru
This patch is extracted from a larger patch that allowed setting the
default returned value from these functions to json or jsonb. That had
problems, but this piece of it is fine. For these functions only json or
jsonb can be specified in the RETURNING clause.
Extracted from an original patch from Nikita Glukhov
Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zihong Yu,
Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby.
Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
This Patch introduces three SQL standard JSON functions:
JSON() (incorrectly mentioned in my commit message for f4fb45d15c)
JSON_SCALAR()
JSON_SERIALIZE()
JSON() produces json values from text, bytea, json or jsonb values, and
has facilitites for handling duplicate keys.
JSON_SCALAR() produces a json value from any scalar sql value, including
json and jsonb.
JSON_SERIALIZE() produces text or bytea from input which containis or
represents json or jsonb;
For the most part these functions don't add any significant new
capabilities, but they will be of use to users wanting standard
compliant JSON handling.
Nikita Glukhov
Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zihong Yu,
Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby.
Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
This introduces the SQL/JSON functions for querying JSON data using
jsonpath expressions. The functions are:
JSON_EXISTS()
JSON_QUERY()
JSON_VALUE()
All of these functions only operate on jsonb. The workaround for now is
to cast the argument to jsonb.
JSON_EXISTS() tests if the jsonpath expression applied to the jsonb
value yields any values. JSON_VALUE() must return a single value, and an
error occurs if it tries to return multiple values. JSON_QUERY() must
return a json object or array, and there are various WRAPPER options for
handling scalar or multi-value results. Both these functions have
options for handling EMPTY and ERROR conditions.
Nikita Glukhov
Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zihong Yu,
Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby.
Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
This patch intrdocuces the SQL standard IS JSON predicate. It operates
on text and bytea values representing JSON as well as on the json and
jsonb types. Each test has an IS and IS NOT variant. The tests are:
IS JSON [VALUE]
IS JSON ARRAY
IS JSON OBJECT
IS JSON SCALAR
IS JSON WITH | WITHOUT UNIQUE KEYS
These are mostly self-explanatory, but note that IS JSON WITHOUT UNIQUE
KEYS is true whenever IS JSON is true, and IS JSON WITH UNIQUE KEYS is
true whenever IS JSON is true except it IS JSON OBJECT is true and there
are duplicate keys (which is never the case when applied to jsonb values).
Nikita Glukhov
Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zihong Yu,
Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby.
Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
This has no in-core callers but will be wanted by extensions.
It's just a thin wrapper around get_query_def, so it adds little code.
Also, fix get_from_clause_item() to force insertion of an alias
for a SUBQUERY RTE item. This is irrelevant to existing uses because
RTE_SUBQUERY items made by the parser always have aliases already.
However, if one tried to use pg_get_querydef() to inspect a post-rewrite
Query, it could be an issue. In any case, get_from_clause_item already
contained logic to force alias insertion for VALUES items, so the lack
of the same for SUBQUERY is a pretty clear oversight.
In passing, replace duplicated code for selection of pretty-print
options with a common macro.
Julien Rouhaud, reviewed by Pavel Stehule, Gilles Darold, and myself
Discussion: https://postgr.es/m/20210627041138.zklczwmu3ms4ufnk@nol
MERGE performs actions that modify rows in the target table using a
source table or query. MERGE provides a single SQL statement that can
conditionally INSERT/UPDATE/DELETE rows -- a task that would otherwise
require multiple PL statements. For example,
MERGE INTO target AS t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED AND t.balance > s.delta THEN
UPDATE SET balance = t.balance - s.delta
WHEN MATCHED THEN
DELETE
WHEN NOT MATCHED AND s.delta > 0 THEN
INSERT VALUES (s.sid, s.delta)
WHEN NOT MATCHED THEN
DO NOTHING;
MERGE works with regular tables, partitioned tables and inheritance
hierarchies, including column and row security enforcement, as well as
support for row and statement triggers and transition tables therein.
MERGE is optimized for OLTP and is parameterizable, though also useful
for large scale ETL/ELT. MERGE is not intended to be used in preference
to existing single SQL commands for INSERT, UPDATE or DELETE since there
is some overhead. MERGE can be used from PL/pgSQL.
MERGE does not support targetting updatable views or foreign tables, and
RETURNING clauses are not allowed either. These limitations are likely
fixable with sufficient effort. Rewrite rules are also not supported,
but it's not clear that we'd want to support them.
Author: Pavan Deolasee <pavan.deolasee@gmail.com>
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Author: Amit Langote <amitlangote09@gmail.com>
Author: Simon Riggs <simon.riggs@enterprisedb.com>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Reviewed-by: Andres Freund <andres@anarazel.de> (earlier versions)
Reviewed-by: Peter Geoghegan <pg@bowt.ie> (earlier versions)
Reviewed-by: Robert Haas <robertmhaas@gmail.com> (earlier versions)
Reviewed-by: Japin Li <japinli@hotmail.com>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-by: Tomas Vondra <tomas.vondra@enterprisedb.com>
Reviewed-by: Zhihong Yu <zyu@yugabyte.com>
Discussion: https://postgr.es/m/CANP8+jKitBSrB7oTgT9CY2i1ObfOt36z0XMraQc+Xrz8QB0nXA@mail.gmail.com
Discussion: https://postgr.es/m/CAH2-WzkJdBuxj9PO=2QaO9-3h3xGbQPZ34kJH=HukRekwM-GZg@mail.gmail.com
Discussion: https://postgr.es/m/20201231134736.GA25392@alvherre.pgsql
This patch introduces the SQL/JSON standard constructors for JSON:
JSON()
JSON_ARRAY()
JSON_ARRAYAGG()
JSON_OBJECT()
JSON_OBJECTAGG()
For the most part these functions provide facilities that mimic
existing json/jsonb functions. However, they also offer some useful
additional functionality. In addition to text input, the JSON() function
accepts bytea input, which it will decode and constuct a json value from.
The other functions provide useful options for handling duplicate keys
and null values.
This series of patches will be followed by a consolidated documentation
patch.
Nikita Glukhov
Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zihong Yu,
Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby.
Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
This introduces some of the building blocks used by the SQL/JSON
constructor and query functions. Specifically, it provides node
executor and grammar support for the FORMAT JSON [ENCODING foo]
clause, and values decorated with it, and for the RETURNING clause.
The following SQL/JSON patches will leverage these.
Nikita Glukhov (who probably deserves an award for perseverance).
Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zihong Yu,
Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby.
Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
This introduces some of the building blocks used by the SQL/JSON
constructor and query functions. Specifically, it provides node
executor and grammar support for the FORMAT JSON [ENCODING foo]
clause, and values decorated with it, and for the RETURNING clause.
The following SQL/JSON patches will leverage these.
Nikita Glukhov (who probably deserves an award for perseverance).
Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup. Erik Rijkers, Zihong Yu and
Himanshu Upadhyaya.
Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
The planner needs to treat GroupingFunc like Aggref for many purposes,
in particular with respect to processing of the argument expressions,
which are not to be evaluated at runtime. A few places hadn't gotten
that memo, notably including subselect.c's processing of outer-level
aggregates. This resulted in assertion failures or wrong plans for
cases in which a GROUPING() construct references an outer aggregation
level.
Also fix missing special cases for GroupingFunc in cost_qual_eval
(resulting in wrong cost estimates for GROUPING(), although it's
not clear that that would affect plan shapes in practice) and in
ruleutils.c (resulting in excess parentheses in pretty-print mode).
Per bug #17088 from Yaoguang Chen. Back-patch to all supported
branches.
Richard Guo, Tom Lane
Discussion: https://postgr.es/m/17088-e33882b387de7f5c@postgresql.org
The SQL standard has been ambiguous about whether null values in
unique constraints should be considered equal or not. Different
implementations have different behaviors. In the SQL:202x draft, this
has been formalized by making this implementation-defined and adding
an option on unique constraint definitions UNIQUE [ NULLS [NOT]
DISTINCT ] to choose a behavior explicitly.
This patch adds this option to PostgreSQL. The default behavior
remains UNIQUE NULLS DISTINCT. Making this happen in the btree code
is pretty easy; most of the patch is just to carry the flag around to
all the places that need it.
The CREATE UNIQUE INDEX syntax extension is not from the standard,
it's my own invention.
I named all the internal flags, catalog columns, etc. in the negative
("nulls not distinct") so that the default PostgreSQL behavior is the
default if the flag is false.
Reviewed-by: Maxim Orlov <orlovmg@gmail.com>
Reviewed-by: Pavel Borisov <pashkin.elfe@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/84e5ee1b-387e-9a54-c326-9082674bde78@enterprisedb.com
Commit 7745bc352 intended to ensure that whole-row Vars would be
printed with "::type" decoration in all contexts where plain
"var.*" notation would result in star-expansion, notably in
ROW() and VALUES() constructs. However, it missed the case of
INSERT with a single-row VALUES, as reported by Timur Khanjanov.
Nosing around ruleutils.c, I found a second oversight: the
code for RowCompareExpr generates ROW() notation without benefit
of an actual RowExpr, and naturally it wasn't in sync :-(.
(The code for FieldStore also does this, but we don't expect that
to generate strictly parsable SQL anyway, so I left it alone.)
Back-patch to all supported branches.
Discussion: https://postgr.es/m/efaba6f9-4190-56be-8ff2-7a1674f9194f@intrans.baku.az
Since this function is defined to accept pg_node_tree values, it could
get applied to any nodetree that can appear in a cataloged pg_node_tree
column. Some such cases can't be supported --- for example, its API
doesn't allow providing referents for more than one relation --- but
we should try to throw a user-facing error rather than an internal
error when encountering such a case.
In support of this, extend expression_tree_walker/mutator to be sure
they'll work on any such node tree (which basically means adding
support for relpartbound node types). That allows us to run pull_varnos
and check for the case of multiple relations before we start processing
the tree. The alternative of changing the low-level error thrown for an
out-of-range varno isn't appealing, because that could mask actual bugs
in other usages of ruleutils.
Per report from Justin Pryzby. This is basically cosmetic, so no
back-patch.
Discussion: https://postgr.es/m/20211219205422.GT17618@telsasoft.com
Extend the foreign key ON DELETE actions SET NULL and SET DEFAULT by
allowing the specification of a column list, like
CREATE TABLE posts (
...
FOREIGN KEY (tenant_id, author_id) REFERENCES users ON DELETE SET NULL (author_id)
);
If a column list is specified, only those columns are set to
null/default, instead of all the columns in the foreign-key
constraint.
This is useful for multitenant or sharded schemas, where the tenant or
shard ID is included in the primary key of all tables but shouldn't be
set to null.
Author: Paul Martinez <paulmtz@google.com>
Discussion: https://www.postgresql.org/message-id/flat/CACqFVBZQyMYJV=njbSMxf+rbDHpx=W=B7AEaMKn8dWn9OZJY7w@mail.gmail.com
If a SQL-standard function body contains an INSERT ... SELECT statement,
any function parameters referenced within the SELECT were always printed
in $N style, rather than using the parameter name if any. While not
strictly incorrect, this wasn't the intention, and it's inconsistent
with the way that such parameters would be printed in any other kind
of statement.
The cause is that the recursion to get_query_def from
get_insert_query_def neglected to pass down the context->namespaces
list, passing constant NIL instead. This is a very ancient oversight,
but AFAICT it had no visible consequences before commit e717a9a18
added an outermost namespace with function parameters. We don't allow
INSERT ... SELECT as a sub-query, except in a top-level WITH clause,
where it couldn't contain any outer references that might need to access
upper namespaces. So although that's arguably a bug, I don't see any
point in changing it before v14.
In passing, harden the code added to get_parameter by e717a9a18 so that
it won't crash if a PARAM_EXTERN Param appears in an unexpected place.
Per report from Erki Eessaar. Code fix by me, regression test case
by Masahiko Sawada.
Discussion: https://postgr.es/m/AM9PR01MB8268347BED344848555167FAFE949@AM9PR01MB8268.eurprd01.prod.exchangelabs.com
Commit 3f50b8263 had an oversight: formerly, to deparse expressions
attached to a plan node, it was only necessary to update the
deparse_namespace ancestors list alongside calling set_deparse_plan.
Now it's necessary to update the ancestors list *first*, because
set_deparse_plan consults it, and one call site got that wrong.
This error was masked in most cases because explain.c uses just one
List object for the ancestors list, updating it in-place as the plan
is scanned, so that we accidentally had the right List assigned to
dpns->ancestors before it was needed. It would fail only if a
WorkTableScan node were the first one that we tried to deparse a
subexpression of.
Per report from Markus Winand. Like the previous patch,
back-patch to v14.
Discussion: https://postgr.es/m/648B0505-AA57-42C2-A2DA-E551DE46FA15@winand.at
The rewriter transformation for SEARCH BREADTH FIRST produces a
FieldSelect on a Var of type RECORD, where the Var references the
recursive union's worktable output. EXPLAIN VERBOSE failed to handle
this case, because it only expected such Vars to appear in CteScans
not WorkTableScans. Fix that, and add some test cases exercising
EXPLAIN on SEARCH and CYCLE queries.
In principle this oversight is an old bug, but it seems that the
case is unreachable without SEARCH BREADTH FIRST, because the
parser fails when attempting to create such a reference manually.
So for today I'll just patch HEAD/v14. Someday we might find that
the code portion of this patch needs to be back-patched further.
Per report from Atsushi Torikoshi.
Discussion: https://postgr.es/m/5bafa66ad529e11860339565c9e7c166@oss.nttdata.com
Up to now the size of a query's rangetable has been limited by the
constants INNER_VAR et al, which mustn't be equal to any real
rangetable index. 65000 doubtless seemed like enough for anybody,
and it still is orders of magnitude larger than the number of joins
we can realistically handle. However, we need a rangetable entry
for each child partition that is (or might be) processed by a query.
Queries with a few thousand partitions are getting more realistic,
so that the day when that limit becomes a problem is in sight,
even if it's not here yet. Hence, let's raise the limit.
Rather than just increase the values of INNER_VAR et al, this patch
adopts the approach of making them small negative values, so that
rangetables could theoretically become as long as INT_MAX.
The bulk of the patch is concerned with changing Var.varno and some
related variables from "Index" (unsigned int) to plain "int". This
is basically cosmetic, with little actual effect other than to help
debuggers print their values nicely. As such, I've only bothered
with changing places that could actually see INNER_VAR et al, which
the parser and most of the planner don't. We do have to be careful
in places that are performing less/greater comparisons on varnos,
but there are very few such places, other than the IS_SPECIAL_VARNO
macro itself.
A notable side effect of this patch is that while it used to be
possible to add INNER_VAR et al to a Bitmapset, that will now
draw an error. I don't see any likelihood that it wouldn't be a
bug to include these fake varnos in a bitmapset of real varnos,
so I think this is all to the good.
Although this touches outfuncs/readfuncs, I don't think a catversion
bump is required, since stored rules would never contain Vars
with these fake varnos.
Andrey Lepikhov and Tom Lane, after a suggestion by Peter Eisentraut
Discussion: https://postgr.es/m/43c7f2f5-1e27-27aa-8c65-c91859d15190@postgrespro.ru
David Rowley