This reverts commit a9c350d9ee.
While that intentionally changed our semantics for CREATE SCHEMA
subcommands, it's being argued that the functionality gain does
not justify potentially-subtle compatibility breakage. The most
useful bit of functionality gain came from commit 404db8f9e
("Execute foreign key constraints in CREATE SCHEMA at the end"),
which we're keeping because it's required by SQL spec and doesn't
seem to create a compatibility hazard by itself.
This is not an exact revert, partly because we're keeping 404db8f9e,
and partly because I kept the API changes that allowed passing down
a ParseState (which allows providing an error cursor for many of the
errors thrown in CREATE SCHEMA).
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/20260904180712.cc.noahmisch@microsoft.com
Backpatch-through: 19
This reverts commit d516974840,
along with parts of commit 049b742daa
("psql: Tighten heuristics for BEGIN/END within CREATE SCHEMA").
While there's nothing particularly wrong with d51697484 in itself,
it depends on a9c350d9e ("Don't try to re-order the subcommands of
CREATE SCHEMA"), and concerns have been raised that the compatibility
impact of that outweighs the benefit of allowing more object types
within CREATE SCHEMA.
It's not possible to revert 049b742da verbatim, because the
CVE-2026-6464 patches 3045a25ba ("Teach psql to skip in-line COPY
... FROM STDIN data after a failure") and cf754f741 ("Save/restore
more lexer state when skipping text due to \if") depend on
infrastructure it added. Instead, rip out just the bits specifically
needed to parse CREATE FUNCTION within CREATE SCHEMA. This results in
lexer code that matches v18-and-earlier as modified by CVE-2026-6464.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/20260904180712.cc.noahmisch@microsoft.com
Backpatch-through: 19
Since d51697484, psql's scanner treats CREATE SCHEMA as a command that
may contain SQL-standard routine bodies, so that semicolons inside
BEGIN ATOMIC ... END blocks do not terminate the command too early.
However, the code counted BEGIN/END throughout CREATE SCHEMA, so that
it could be fooled by valid (and previously accepted) code such as
CREATE SCHEMA s CREATE VIEW begin AS SELECT 1;
Improve this by explicitly checking whether each CREATE sub-clause is
CREATE [OR REPLACE] {FUNCTION|PROCEDURE}, and only counting BEGIN/END
within those clauses. Since CREATE FUNCTION/PROCEDURE wasn't allowed
in CREATE SCHEMA before d51697484, this will not risk failure on any
cases that worked before v19.
There remain cases that fool the top-level CREATE FUNCTION/PROCEDURE
heuristic and thus also the CREATE SCHEMA case, for example
CREATE FUNCTION begin () ...
But that's been true all along with no field complaints, so we'll
leave that issue for another day.
In the name of keeping things readable, move the logic supporting
this out of the {identifier} flex rule and into some small new
subroutines. Also rename existing related PsqlScanState fields
to help distinguish them from the added fields.
This patch also fixes what seems to me (tgl) a small bug: \;
would reset BEGIN/END detection even when inside parens or BEGIN.
That's unlike what a plain semicolon would do, and no such effect
is suggested by the documentation.
Author: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/8E03BB8D-003D-4850-9772-5F8015A5A0C7@gmail.com
Having rejected the principle that we should know how to re-order
the sub-commands of CREATE SCHEMA, there is not really anything
except a little coding to stop us from supporting more object types.
This patch adds support for creating functions (including procedures
and aggregates), operators, types (including domains), collations,
and text search objects.
SQL:2021 specifies that we should allow functions, procedures,
types, domains, and collations, so this moves us a great deal
closer to full SQL compatibility of CREATE SCHEMA. What remains
missing from their list are casts, transforms, roles, and some
object types we don't support yet (e.g. CREATE CHARACTER SET).
Supporting casts or transforms would be problematic because
they don't have names at all, let alone schema-qualified names,
so it'd be quite a stretch to say that they belong to a schema.
Roles likewise are not schema-qualified, plus they are global
to a cluster, making it even less reasonable to consider them
as belonging to a schema. So I don't see us trying to complete
the list.
User-defined aggregates and operators are outside the spec's ken,
as are text search objects, so adding them does not do anything for
spec compatibility. But they go along with these other object types,
plus it takes no additional code to support them since they are
represented as DefineStmts like some variants of CREATE TYPE.
It would indeed take some effort to reject them.
Author: Kirill Reshke <reshkekirill@gmail.com>
Author: Jian He <jian.universality@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CALdSSPh4jUSDsWu3K58hjO60wnTRR0DuO4CKRcwa8EVuOSfXxg@mail.gmail.com
The previous patch simplified CREATE SCHEMA's behavior to "execute all
subcommands in the order they are written". However, that's a bit too
simple, as the spec clearly requires forward references in foreign key
constraint clauses to work, see feature F311-01. (Most other SQL
implementations seem to read more into the spec than that, but it's
not clear that there's justification for more in the text, and this is
the only case that doesn't introduce unresolvable issues.) We never
implemented that before, but let's do so now.
To fix it, transform FOREIGN KEY clauses into ALTER TABLE ... ADD
FOREIGN KEY commands and append them to the end of the CREATE SCHEMA's
subcommand list. This works because the foreign key constraints are
independent and don't affect any other DDL that might be in CREATE
SCHEMA. For simplicity, we do this for all FOREIGN KEY clauses even
if they would have worked where they were.
Author: Jian He <jian.universality@gmail.com>
Co-authored-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/1075425.1732993688@sss.pgh.pa.us
transformCreateSchemaStmtElements has always believed that it is
supposed to re-order the subcommands of CREATE SCHEMA into a safe
execution order. However, it is nowhere near being capable of doing
that correctly. Nor is there reason to think that it ever will be,
or that that is a well-defined requirement. (The SQL standard does
say that it should be possible to do foreign-key forward references
within CREATE SCHEMA, but it's not clear that the text requires
anything more than that.) Moreover, the problem will get worse as
we add more subcommand types. Let's just drop the whole idea and
execute the commands in the order given, which seems like a much
less astonishment-prone definition anyway. The foreign-key issue
will be handled in a follow-up patch.
This will result in a release-note-worthy incompatibility,
which is that forward references like
CREATE SCHEMA myschema
CREATE VIEW myview AS SELECT * FROM mytable
CREATE TABLE mytable (...);
used to work and no longer will. Considering how many closely
related variants never worked, this isn't much of a loss.
Along the way, pass down a ParseState so that we can provide an
error cursor for "wrong schema name" and related errors, and fix
transformCreateSchemaStmtElements so that it doesn't scribble
on the parsetree passed to it.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Kirill Reshke <reshkekirill@gmail.com>
Reviewed-by: Jian He <jian.universality@gmail.com>
Discussion: https://postgr.es/m/1075425.1732993688@sss.pgh.pa.us
CREATE SCHEMA AUTHORIZATION with appended schema elements can lead to
crashes when comparing the schema name of the query with the schemas
used in the qualification of some clauses in the elements' queries.
The origin of the problem is that the transformation routine for the
elements listed in a CREATE SCHEMA query uses as new, expected, schema
name the one listed in CreateSchemaStmt itself. However, depending on
the query, CreateSchemaStmt.schemaname may be NULL, being computed
instead from the role specification of the query given by the
AUTHORIZATION clause, that could be either:
- A user name string, with the new schema name being set to the same
value as the role given.
- Guessed from CURRENT_ROLE, SESSION_ROLE or CURRENT_ROLE, with a new
schema name computed from the security context where CREATE SCHEMA is
running.
Regression tests are added for CREATE SCHEMA with some appended elements
(some of them with schema qualifications), covering also some role
specification patterns.
While on it, this simplifies the context structure used during the
transformation of the elements listed in a CREATE SCHEMA query by
removing the fields for the role specification and the role type. They
were not used, and for the role specification this could be confusing as
the schema name may by extracted from that at the beginning of
CreateSchemaCommand().
This issue exists for a long time, so backpatch down to all the versions
supported.
Reported-by: Song Hongyu
Author: Michael Paquier
Reviewed-by: Richard Guo
Discussion: https://postgr.es/m/17909-f65c12dfc5f0451d@postgresql.org
Backpatch-through: 11
