I wonder if trying to add a relation to a publication that it is already a
part should be considered a no-op, instead of causing an error (which
happens in the ALTER PUBLICATION ADD TABLES case).
create table bar (a int);
create publication mypub for table bar;
alter publication mypub add table bar;
ERROR: relation "bar" is already member of publication "mypub"
2nd command should be a no-op, IMHO.
Consider the following (I know we're discussing inheritance elsewhere as
well):
create table foo (a int);
create table baz () inherits (foo);
alter table bar inherit foo;
alter table mypub add table foo;
ERROR: relation "bar" is already member of publication "mypub"
There is no way to add foo and children other than bar to mypub without
doing so one-by-one.
If my proposal to make that a no-op sounds desirable, attached patch
implements that.
Thanks,
Amit
>From 810b7bd26458b625e4f9badb0a032effc954d060 Mon Sep 17 00:00:00 2001
From: amit <amitlangot...@gmail.com>
Date: Thu, 13 Apr 2017 19:00:22 +0900
Subject: [PATCH] Fix how duplicate addition to a publication is prevented
Treat such an attempt as a no-op instead of causing an error.
---
src/backend/catalog/pg_publication.c | 18 ++++--------------
src/backend/commands/publicationcmds.c | 14 +++++++-------
src/include/catalog/pg_publication.h | 3 +--
src/test/regress/expected/publication.out | 1 -
4 files changed, 12 insertions(+), 24 deletions(-)
diff --git a/src/backend/catalog/pg_publication.c b/src/backend/catalog/pg_publication.c
index 9330e2380a..5af9af0f6e 100644
--- a/src/backend/catalog/pg_publication.c
+++ b/src/backend/catalog/pg_publication.c
@@ -101,8 +101,7 @@ is_publishable_class(Oid relid, Form_pg_class reltuple)
* Insert new publication / relation mapping.
*/
ObjectAddress
-publication_add_relation(Oid pubid, Relation targetrel,
- bool if_not_exists)
+publication_add_relation(Oid pubid, Relation targetrel)
{
Relation rel;
HeapTuple tup;
@@ -110,29 +109,20 @@ publication_add_relation(Oid pubid, Relation targetrel,
bool nulls[Natts_pg_publication_rel];
Oid relid = RelationGetRelid(targetrel);
Oid prrelid;
- Publication *pub = GetPublication(pubid);
ObjectAddress myself,
referenced;
rel = heap_open(PublicationRelRelationId, RowExclusiveLock);
/*
- * Check for duplicates. Note that this does not really prevent
- * duplicates, it's here just to provide nicer error message in common
- * case. The real protection is the unique key on the catalog.
+ * If target relation is already a part of the publication, nothing to
+ * to do here.
*/
if (SearchSysCacheExists2(PUBLICATIONRELMAP, ObjectIdGetDatum(relid),
ObjectIdGetDatum(pubid)))
{
heap_close(rel, RowExclusiveLock);
-
- if (if_not_exists)
- return InvalidObjectAddress;
-
- ereport(ERROR,
- (errcode(ERRCODE_DUPLICATE_OBJECT),
- errmsg("relation \"%s\" is already member of publication \"%s\"",
- RelationGetRelationName(targetrel), pub->name)));
+ return InvalidObjectAddress;
}
check_publication_add_relation(targetrel);
diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 541da7ee12..100d2ab9b5 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -52,7 +52,7 @@
static List *OpenTableList(List *tables);
static void CloseTableList(List *rels);
-static void PublicationAddTables(Oid pubid, List *rels, bool if_not_exists,
+static void PublicationAddTables(Oid pubid, List *rels,
AlterPublicationStmt *stmt);
static void PublicationDropTables(Oid pubid, List *rels, bool missing_ok);
@@ -232,7 +232,7 @@ CreatePublication(CreatePublicationStmt *stmt)
Assert(list_length(stmt->tables) > 0);
rels = OpenTableList(stmt->tables);
- PublicationAddTables(puboid, rels, true, NULL);
+ PublicationAddTables(puboid, rels, NULL);
CloseTableList(rels);
}
@@ -357,7 +357,7 @@ AlterPublicationTables(AlterPublicationStmt *stmt, Relation rel,
rels = OpenTableList(stmt->tables);
if (stmt->tableAction == DEFELEM_ADD)
- PublicationAddTables(pubid, rels, false, stmt);
+ PublicationAddTables(pubid, rels, stmt);
else if (stmt->tableAction == DEFELEM_DROP)
PublicationDropTables(pubid, rels, false);
else /* DEFELEM_SET */
@@ -399,7 +399,7 @@ AlterPublicationTables(AlterPublicationStmt *stmt, Relation rel,
* Don't bother calculating the difference for adding, we'll catch
* and skip existing ones when doing catalog update.
*/
- PublicationAddTables(pubid, rels, true, stmt);
+ PublicationAddTables(pubid, rels, stmt);
CloseTableList(delrels);
}
@@ -595,7 +595,7 @@ CloseTableList(List *rels)
* Add listed tables to the publication.
*/
static void
-PublicationAddTables(Oid pubid, List *rels, bool if_not_exists,
+PublicationAddTables(Oid pubid, List *rels,
AlterPublicationStmt *stmt)
{
ListCell *lc;
@@ -612,8 +612,8 @@ PublicationAddTables(Oid pubid, List *rels, bool if_not_exists,
aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
RelationGetRelationName(rel));
- obj = publication_add_relation(pubid, rel, if_not_exists);
- if (stmt)
+ obj = publication_add_relation(pubid, rel);
+ if (obj.objectId != InvalidOid)
{
EventTriggerCollectSimpleCommand(obj, InvalidObjectAddress,
(Node *) stmt);
diff --git a/src/include/catalog/pg_publication.h b/src/include/catalog/pg_publication.h
index f3c4f3932b..07407f6e94 100644
--- a/src/include/catalog/pg_publication.h
+++ b/src/include/catalog/pg_publication.h
@@ -93,8 +93,7 @@ extern List *GetPublicationRelations(Oid pubid);
extern List *GetAllTablesPublications(void);
extern List *GetAllTablesPublicationRelations(void);
-extern ObjectAddress publication_add_relation(Oid pubid, Relation targetrel,
- bool if_not_exists);
+extern ObjectAddress publication_add_relation(Oid pubid, Relation targetrel);
extern Oid get_publication_oid(const char *pubname, bool missing_ok);
extern char *get_publication_name(Oid pubid);
diff --git a/src/test/regress/expected/publication.out b/src/test/regress/expected/publication.out
index 0964718a60..7a84cc71a7 100644
--- a/src/test/regress/expected/publication.out
+++ b/src/test/regress/expected/publication.out
@@ -78,7 +78,6 @@ DETAIL: Only tables can be added to publications.
CREATE PUBLICATION testpub_fortbl FOR TABLE testpub_tbl1, pub_test.testpub_nopk;
-- fail - already added
ALTER PUBLICATION testpub_fortbl ADD TABLE testpub_tbl1;
-ERROR: relation "testpub_tbl1" is already member of publication "testpub_fortbl"
-- fail - already added
CREATE PUBLICATION testpub_fortbl FOR TABLE testpub_tbl1;
ERROR: publication "testpub_fortbl" already exists
--
2.11.0
--
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