Re: NOT ENFORCED constraint feature

jian he <jian.universality@gmail.com>

From: jian he <jian.universality@gmail.com>

To: Amul Sul <sulamul@gmail.com>

Cc: Peter Eisentraut <peter@eisentraut.org>, pgsql-hackers <pgsql-hackers@postgresql.org>, Joel Jacobson <joel@compiler.org>

Date: 2024-12-05T05:32:20Z

Lists: pgsql-hackers

Commits

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Add support for NOT ENFORCED in foreign key constraints
- eec0040c4bcd 18.0 landed
Expand test a bit
- 5d5f415816a6 18.0 landed
refactor: Pass relation OID instead of Relation to createForeignKeyCheckTriggers()
- ef7a5af77d44 18.0 landed
refactor: Split ATExecAlterConstraintInternal()
- 639238b978fe 18.0 landed
refactor: Move some code that updates pg_constraint to a separate function
- a3280e2a494f 18.0 landed
Move RemoveInheritedConstraint() call slightly earlier
- dabccf45139a 18.0 landed
refactor: Split tryAttachPartitionForeignKey()
- 1d26c2d2c4b8 18.0 landed
refactor: re-add ATExecAlterChildConstr()
- 64224a834ce4 18.0 landed
Add ATAlterConstraint struct for ALTER .. CONSTRAINT
- 80d7f990496b 18.0 landed
refactor: split ATExecAlterConstrRecurse()
- 7a947ed25b54 18.0 landed
Add support for NOT ENFORCED in CHECK constraints
- ca87c415e2fc 18.0 landed

hi.
accidentally hit segfault.
create table c11 (a int not enforced);
create table c11 (a int enforced);
we can solve it via the following or changing SUPPORTS_ATTRS accordingly.

diff --git a/src/backend/parser/parse_utilcmd.c
b/src/backend/parser/parse_utilcmd.c
index 5ab44149e5..fe1116c092 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -3965,7 +3965,7 @@ transformConstraintAttrs(CreateStmtContext *cxt,
List *constraintList)
                                break;
                        case CONSTR_ATTR_ENFORCED:
-                               if (lastprimarycon &&
+                               if (lastprimarycon == NULL ||
                                        lastprimarycon->contype != CONSTR_CHECK)
                                        ereport(ERROR,

(errcode(ERRCODE_SYNTAX_ERROR),
@@ -3981,7 +3981,7 @@ transformConstraintAttrs(CreateStmtContext *cxt,
List *constraintList)
                                break;
                        case CONSTR_ATTR_NOT_ENFORCED:
-                               if (lastprimarycon &&
+                               if (lastprimarycon == NULL ||
                                        lastprimarycon->contype != CONSTR_CHECK)
                                        ereport(ERROR,

(errcode(ERRCODE_SYNTAX_ERROR),


ALTER DOMAIN constraint_comments_dom ADD CONSTRAINT the_constraint
CHECK (value > 0) NOT ENFORCED;
ERROR:  CHECK constraints cannot be marked NOT ENFORCED

the error message is not good?  maybe better option would be:
ERROR:  DOMAIN CHECK constraints cannot be marked NOT ENFORCED

we can do it like:
index 833b3be02b..4a7ab0c2a3 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -4342,7 +4342,7 @@ DomainConstraintElem:
                                        n->location = @1;
                                        n->raw_expr = $3;
                                        n->cooked_expr = NULL;
-                                       processCASbits($5, @5, "CHECK",
+                                      processCASbits($5, @5, "DOMAIN CHECK",

NULL, NULL, NULL, &n->skip_validation,

&n->is_no_inherit, yyscanner);