From d6f32e7b77ce5adbf47fa5a01c3f938e272439bf Mon Sep 17 00:00:00 2001
From: Adam Guo <adamguo@amazon.com>
Date: Wed, 26 Mar 2025 17:07:26 +0000
Subject: [PATCH 01/13] Add querystring column to pg_ivm_immv.

---
 Makefile               | 2 +-
 createas.c             | 1 +
 pg_ivm--1.10--1.11.sql | 1 +
 pg_ivm.control         | 2 +-
 pg_ivm.h               | 3 ++-
 5 files changed, 6 insertions(+), 3 deletions(-)
 create mode 100644 pg_ivm--1.10--1.11.sql

diff --git a/Makefile b/Makefile
index 9f770f6..e225eaa 100644
--- a/Makefile
+++ b/Makefile
@@ -18,7 +18,7 @@ DATA = pg_ivm--1.0.sql \
        pg_ivm--1.3--1.4.sql pg_ivm--1.4--1.5.sql pg_ivm--1.5--1.6.sql \
        pg_ivm--1.6--1.7.sql pg_ivm--1.7--1.8.sql pg_ivm--1.8--1.9.sql \
        pg_ivm--1.9--1.10.sql \
-	   pg_ivm--1.10.sql
+	   pg_ivm--1.10.sql pg_ivm--1.10--1.11.sql
 
 REGRESS = pg_ivm create_immv refresh_immv
 
diff --git a/createas.c b/createas.c
index b41fd1d..8c6ce4d 100644
--- a/createas.c
+++ b/createas.c
@@ -1719,6 +1719,7 @@ StoreImmvQuery(Oid viewOid, Query *viewQuery)
 
 	memset(values, 0, sizeof(values));
 	memset(isNulls, false, sizeof(isNulls));
+	isNulls[Anum_pg_ivm_immv_querystring - 1] = true;
 
 	values[Anum_pg_ivm_immv_immvrelid -1 ] = ObjectIdGetDatum(viewOid);
 	values[Anum_pg_ivm_immv_ispopulated -1 ] = BoolGetDatum(false);
diff --git a/pg_ivm--1.10--1.11.sql b/pg_ivm--1.10--1.11.sql
new file mode 100644
index 0000000..b093d22
--- /dev/null
+++ b/pg_ivm--1.10--1.11.sql
@@ -0,0 +1 @@
+ALTER TABLE pgivm.pg_ivm_immv ADD COLUMN querystring text;
diff --git a/pg_ivm.control b/pg_ivm.control
index 27dc5af..fcfe90d 100644
--- a/pg_ivm.control
+++ b/pg_ivm.control
@@ -1,6 +1,6 @@
 # incremental view maintenance extension_
 comment = 'incremental view maintenance on PostgreSQL'
-default_version = '1.10'
+default_version = '1.11'
 module_pathname = '$libdir/pg_ivm'
 relocatable = false 
 schema = pg_catalog
diff --git a/pg_ivm.h b/pg_ivm.h
index 88d7003..ae79e45 100644
--- a/pg_ivm.h
+++ b/pg_ivm.h
@@ -20,12 +20,13 @@
 #include "tcop/dest.h"
 #include "utils/queryenvironment.h"
 
-#define Natts_pg_ivm_immv 4
+#define Natts_pg_ivm_immv 5
 
 #define Anum_pg_ivm_immv_immvrelid 1
 #define Anum_pg_ivm_immv_viewdef 2
 #define Anum_pg_ivm_immv_ispopulated 3
 #define Anum_pg_ivm_immv_lastivmupdate 4
+#define Anum_pg_ivm_immv_querystring 5
 
 /* pg_ivm.c */
 

From 7a36cc501ad4b7b0114fe847e4cf1d3dede4aaea Mon Sep 17 00:00:00 2001
From: Adam Guo <adamguo@amazon.com>
Date: Wed, 26 Mar 2025 17:20:36 +0000
Subject: [PATCH 02/13] Add event trigger to update querystring.

---
 pg_ivm--1.10--1.11.sql | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/pg_ivm--1.10--1.11.sql b/pg_ivm--1.10--1.11.sql
index b093d22..6819be4 100644
--- a/pg_ivm--1.10--1.11.sql
+++ b/pg_ivm--1.10--1.11.sql
@@ -1 +1,23 @@
 ALTER TABLE pgivm.pg_ivm_immv ADD COLUMN querystring text;
+
+CREATE FUNCTION pgivm.refresh_query_strings()
+RETURNS event_trigger LANGUAGE plpgsql AS
+$$
+DECLARE
+	old_search_path text;
+BEGIN
+	-- Empty search path so that get_immv_def returns a fully-qualified query.
+	SELECT setting INTO old_search_path FROM pg_catalog.pg_settings
+		WHERE name = 'search_path';
+	SET search_path = '';
+
+	UPDATE pgivm.pg_ivm_immv SET querystring = pgivm.get_immv_def(immvrelid);
+
+	-- Reset search path to the original value.
+	EXECUTE format('SET search_path = %s', old_search_path);
+END
+$$;
+
+CREATE EVENT TRIGGER refresh_query_strings
+ON ddl_command_end
+EXECUTE FUNCTION pgivm.refresh_query_strings();

From 3524de96acdb554af3faf4619206a293abf8c659 Mon Sep 17 00:00:00 2001
From: Adam Guo <adamguo@amazon.com>
Date: Wed, 26 Mar 2025 18:32:09 +0000
Subject: [PATCH 03/13] Store querystring on create.

---
 createas.c             | 10 +++++++++-
 pg_ivm--1.10--1.11.sql |  4 ++--
 pg_ivm.c               |  9 +++++++++
 pg_ivm.h               |  5 +++++
 ruleutils.c            |  7 +++++++
 5 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/createas.c b/createas.c
index 8c6ce4d..026cce3 100644
--- a/createas.c
+++ b/createas.c
@@ -41,6 +41,7 @@
 #include "rewrite/rewriteManip.h"
 #include "utils/builtins.h"
 #include "utils/fmgroids.h"
+#include "utils/guc.h"
 #include "utils/lsyscache.h"
 #include "utils/regproc.h"
 #include "utils/rel.h"
@@ -1710,20 +1711,27 @@ static void
 StoreImmvQuery(Oid viewOid, Query *viewQuery)
 {
 	char   *querytree = nodeToString((Node *) viewQuery);
+	char   *querystring;
 	Datum values[Natts_pg_ivm_immv];
 	bool isNulls[Natts_pg_ivm_immv];
+	Relation matviewRel;
 	Relation pgIvmImmv;
 	TupleDesc tupleDescriptor;
 	HeapTuple heapTuple;
 	ObjectAddress	address;
 
+	RestrictSearchPath();
+	matviewRel = table_open(viewOid, AccessShareLock);
+	querystring = pg_ivm_get_viewdef_internal(viewQuery, matviewRel, true);
+	table_close(matviewRel, NoLock);
+
 	memset(values, 0, sizeof(values));
 	memset(isNulls, false, sizeof(isNulls));
-	isNulls[Anum_pg_ivm_immv_querystring - 1] = true;
 
 	values[Anum_pg_ivm_immv_immvrelid -1 ] = ObjectIdGetDatum(viewOid);
 	values[Anum_pg_ivm_immv_ispopulated -1 ] = BoolGetDatum(false);
 	values[Anum_pg_ivm_immv_viewdef -1 ] = CStringGetTextDatum(querytree);
+	values[Anum_pg_ivm_immv_querystring - 1] = CStringGetTextDatum(querystring);
 
 	pgIvmImmv = table_open(PgIvmImmvRelationId(), RowExclusiveLock);
 
diff --git a/pg_ivm--1.10--1.11.sql b/pg_ivm--1.10--1.11.sql
index 6819be4..745f3dc 100644
--- a/pg_ivm--1.10--1.11.sql
+++ b/pg_ivm--1.10--1.11.sql
@@ -1,7 +1,7 @@
-ALTER TABLE pgivm.pg_ivm_immv ADD COLUMN querystring text;
+ALTER TABLE pgivm.pg_ivm_immv ADD COLUMN querystring text NOT NULL;
 
 CREATE FUNCTION pgivm.refresh_query_strings()
-RETURNS event_trigger LANGUAGE plpgsql AS
+RETURNS event_trigger LANGUAGE plpgsql SECURITY DEFINER AS
 $$
 DECLARE
 	old_search_path text;
diff --git a/pg_ivm.c b/pg_ivm.c
index 19d0e0e..fe5c9bb 100644
--- a/pg_ivm.c
+++ b/pg_ivm.c
@@ -458,3 +458,12 @@ PgIvmFuncName(char *name)
 {
     return list_make2(makeString("pgivm"), makeString(name));
 }
+
+#if defined(PG_VERSION_NUM) && (PG_VERSION_NUM < 170000)
+void
+RestrictSearchPath(void)
+{
+	set_config_option("search_path", "pg_catalog, pg_temp", PGC_USERSET,
+					  PGC_S_SESSION, GUC_ACTION_SAVE, true, 0, false);
+}
+#endif
diff --git a/pg_ivm.h b/pg_ivm.h
index ae79e45..e334141 100644
--- a/pg_ivm.h
+++ b/pg_ivm.h
@@ -65,8 +65,13 @@ extern bool isIvmName(const char *s);
 /* ruleutils.c */
 
 extern char *pg_ivm_get_viewdef(Relation immvrel, bool pretty);
+extern char *pg_ivm_get_viewdef_internal(Query *query, Relation immvrel, bool pretty);
 
 /* subselect.c */
 extern void inline_cte(PlannerInfo *root, CommonTableExpr *cte);
 
+#if defined(PG_VERSION_NUM) && (PG_VERSION_NUM < 170000)
+extern void RestrictSearchPath(void);
+#endif
+
 #endif
diff --git a/ruleutils.c b/ruleutils.c
index dfe1fe4..2c7e080 100644
--- a/ruleutils.c
+++ b/ruleutils.c
@@ -43,6 +43,13 @@ char *
 pg_ivm_get_viewdef(Relation immvrel, bool pretty)
 {
 	Query *query = get_immv_query(immvrel);
+
+	return pg_ivm_get_viewdef_internal(query, immvrel, pretty);
+}
+
+char *
+pg_ivm_get_viewdef_internal(Query *query, Relation immvrel, bool pretty)
+{
 	TupleDesc resultDesc = RelationGetDescr(immvrel);
 
 #if defined(PG_VERSION_NUM) && (PG_VERSION_NUM >= 150000)

From 0a5bd500e6fa3efcc265fa2976d4a963375a0b65 Mon Sep 17 00:00:00 2001
From: Adam Guo <adamguo@amazon.com>
Date: Wed, 26 Mar 2025 21:42:06 +0000
Subject: [PATCH 04/13] refresh_immv: reparse the query string

---
 matview.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 pg_ivm.c  | 33 ++++++++++++++++++-----
 pg_ivm.h  |  2 ++
 3 files changed, 108 insertions(+), 7 deletions(-)

diff --git a/matview.c b/matview.c
index 66709b5..aa95b58 100644
--- a/matview.c
+++ b/matview.c
@@ -233,6 +233,7 @@ static void clean_up_IVM_hash_entry(MV_TriggerHashEntry *entry, bool is_abort,
 static void setLastUpdateXid(Oid immv_oid, FullTransactionId xid);
 static FullTransactionId getLastUpdateXid(Oid immv_oid);
 
+static Query *recreate_immv_query(Relation matviewRel);
 
 /* SQL callable functions */
 PG_FUNCTION_INFO_V1(IVM_immediate_before);
@@ -388,7 +389,7 @@ RefreshImmvByOid(Oid matviewOid, bool is_create, bool skipData,
 	systable_endscan(scan);
 	table_close(pgIvmImmv, NoLock);
 
-	viewQuery = get_immv_query(matviewRel);
+	viewQuery = recreate_immv_query(matviewRel);
 
 	/* For IMMV, we need to rewrite matview query */
 	if (!skipData)
@@ -713,6 +714,83 @@ get_immv_query(Relation matviewRel)
 	return query;
 }
 
+/*
+ * recreate_immv_query
+ *
+ * Parse the querystring for this IMMV.  Update the viewdef column in
+ * pg_ivm_immv and return the Query tree.
+ */
+static Query *
+recreate_immv_query(Relation matviewRel)
+{
+	Relation pgIvmImmv = table_open(PgIvmImmvRelationId(), AccessShareLock);
+	TupleDesc tupdesc = RelationGetDescr(pgIvmImmv);
+	SysScanDesc scan;
+	ScanKeyData key;
+	HeapTuple tup;
+	bool isnull;
+	Datum datum;
+	Query *query = NULL;
+	IntoClause *into;
+	ParseState *pstate = NULL;
+	CreateTableAsStmt *stmt;
+	const char *querystring;
+	const char *relname;
+	const char *querytree;
+
+	Datum values[Natts_pg_ivm_immv];
+	bool nulls[Natts_pg_ivm_immv];
+	bool replaces[Natts_pg_ivm_immv];
+	HeapTuple newtup = NULL;
+
+	ScanKeyInit(&key,
+			    Anum_pg_ivm_immv_immvrelid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(RelationGetRelid(matviewRel)));
+	scan = systable_beginscan(pgIvmImmv, PgIvmImmvPrimaryKeyIndexId(),
+								  true, NULL, 1, &key);
+
+	tup = systable_getnext(scan);
+
+	if (!HeapTupleIsValid(tup))
+	{
+		systable_endscan(scan);
+		table_close(pgIvmImmv, NoLock);
+		return NULL;
+	}
+
+	datum = heap_getattr(tup, Anum_pg_ivm_immv_querystring, tupdesc, &isnull);
+	Assert(!isnull);
+	querystring = TextDatumGetCString(datum);
+
+	relname = psprintf("%s.%s",
+					   get_namespace_name(get_rel_namespace(matviewRel->rd_id)),
+					   get_rel_name(matviewRel->rd_id));
+
+	parse_immv_query(relname, querystring, &query, &pstate);
+	stmt = castNode(CreateTableAsStmt, query->utilityStmt);
+	into = stmt->into;
+
+	query = castNode(Query, stmt->query);
+	query = rewriteQueryForIMMV(query, into->colNames);
+	querytree = nodeToString((Node *) query);
+
+	memset(values, 0, sizeof(values));
+	memset(nulls, 0, sizeof(nulls));
+	memset(replaces, 0, sizeof(replaces));
+	values[Anum_pg_ivm_immv_viewdef - 1] = CStringGetTextDatum(querytree);
+	replaces[Anum_pg_ivm_immv_viewdef - 1] = true;
+
+	newtup = heap_modify_tuple(tup, tupdesc, values, nulls, replaces);
+	CatalogTupleUpdate(pgIvmImmv, &newtup->t_self, newtup);
+	heap_freetuple(newtup);
+
+	systable_endscan(scan);
+	table_close(pgIvmImmv, NoLock);
+
+	return query;
+}
+
 static Tuplestorestate *
 tuplestore_copy(Tuplestorestate *tuplestore, Relation rel)
 {
diff --git a/pg_ivm.c b/pg_ivm.c
index fe5c9bb..a005e07 100644
--- a/pg_ivm.c
+++ b/pg_ivm.c
@@ -177,17 +177,39 @@ create_immv(PG_FUNCTION_ARGS)
 	text	*t_sql = PG_GETARG_TEXT_PP(1);
 	char	*relname = text_to_cstring(t_relname);
 	char	*sql = text_to_cstring(t_sql);
+
+	Query	*query = NULL;
+	QueryCompletion qc;
+	ParseState	*pstate = NULL;
+
+	parse_immv_query(relname, sql, &query, &pstate);
+
+	ExecCreateImmv(pstate, (CreateTableAsStmt *) query->utilityStmt, &qc);
+
+	PG_RETURN_INT64(qc.nprocessed);
+}
+
+/*
+ * parse_immv_query
+ *
+ * Parse an IMMV definition query and return the Query tree and ParseState using
+ * the supplied pointers.
+ */
+void
+parse_immv_query(const char *relname, const char *sql, Query **query_ret,
+				 ParseState **pstate_ret)
+{
 	List	*parsetree_list;
 	RawStmt	*parsetree;
-	Query	*query;
-	QueryCompletion qc;
 	List	*names = NIL;
 	List	*colNames = NIL;
 
-	ParseState *pstate = make_parsestate(NULL);
 	CreateTableAsStmt *ctas;
 	StringInfoData command_buf;
+	Query	*query;
+	ParseState	*pstate;
 
+	pstate = make_parsestate(NULL);
 	parseNameAndColumns(relname, &names, &colNames);
 
 	initStringInfo(&command_buf);
@@ -230,9 +252,8 @@ create_immv(PG_FUNCTION_ARGS)
 	query = transformStmt(pstate, (Node *)ctas);
 	Assert(query->commandType == CMD_UTILITY && IsA(query->utilityStmt, CreateTableAsStmt));
 
-	ExecCreateImmv(pstate, (CreateTableAsStmt *) query->utilityStmt, &qc);
-
-	PG_RETURN_INT64(qc.nprocessed);
+	*query_ret = query;
+	*pstate_ret = pstate;
 }
 
 /*
diff --git a/pg_ivm.h b/pg_ivm.h
index e334141..04c83f0 100644
--- a/pg_ivm.h
+++ b/pg_ivm.h
@@ -35,6 +35,8 @@ extern Oid PgIvmImmvRelationId(void);
 extern Oid PgIvmImmvPrimaryKeyIndexId(void);
 extern bool isImmv(Oid immv_oid);
 extern List *PgIvmFuncName(char *name);
+extern void parse_immv_query(const char *relname, const char *sql,
+							 Query **query_ret, ParseState **pstate_ret);
 
 /* createas.c */
 

From 7bc34dfa908556c87b62e2ccb9af2315c5bc6710 Mon Sep 17 00:00:00 2001
From: Adam Guo <adamguo@amazon.com>
Date: Wed, 26 Mar 2025 22:44:45 +0000
Subject: [PATCH 05/13] Add recreate_all_immvs function.

Recreate change prevent triggers during refresh_immv in addition to base
table triggers.
---
 matview.c              |  6 +++++-
 pg_ivm--1.10--1.11.sql | 23 ++++++++++++++++++++++-
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/matview.c b/matview.c
index aa95b58..8854124 100644
--- a/matview.c
+++ b/matview.c
@@ -444,7 +444,8 @@ RefreshImmvByOid(Oid matviewOid, bool is_create, bool skipData,
 				tgform = (Form_pg_trigger) GETSTRUCT(tgtup);
 
 				/* If trigger is created by IMMV, delete it. */
-				if (strncmp(NameStr(tgform->tgname), "IVM_trigger_", 12) == 0)
+				if (strncmp(NameStr(tgform->tgname), "IVM_trigger_", 12) == 0 ||
+					strncmp(NameStr(tgform->tgname), "IVM_prevent_", 12) == 0)
 				{
 					obj.classId = foundDep->classid;
 					obj.objectId = foundDep->objid;
@@ -474,7 +475,10 @@ RefreshImmvByOid(Oid matviewOid, bool is_create, bool skipData,
 	 * is created.
 	 */
 	if (!skipData && !oldPopulated)
+	{
 		CreateIvmTriggersOnBaseTables(dataQuery, matviewOid);
+		CreateChangePreventTrigger(matviewOid);
+	}
 
 	/*
 	 * Create the transient table that will receive the regenerated data. Lock
diff --git a/pg_ivm--1.10--1.11.sql b/pg_ivm--1.10--1.11.sql
index 745f3dc..4f99101 100644
--- a/pg_ivm--1.10--1.11.sql
+++ b/pg_ivm--1.10--1.11.sql
@@ -1,5 +1,24 @@
 ALTER TABLE pgivm.pg_ivm_immv ADD COLUMN querystring text NOT NULL;
 
+CREATE FUNCTION pgivm.recreate_all_immvs() RETURNS VOID LANGUAGE PLPGSQL AS
+$$
+BEGIN
+	PERFORM pgivm.refresh_immv(n.nspname || '.' || c.relname, false)
+		FROM pgivm.pg_ivm_immv as ivm
+		JOIN pg_catalog.pg_class as c
+		ON c.oid = ivm.immvrelid
+		JOIN pg_catalog.pg_namespace as n
+		ON c.relnamespace = n.oid;
+
+	PERFORM pgivm.refresh_immv(n.nspname || '.' || c.relname, true)
+		FROM pgivm.pg_ivm_immv as ivm
+		JOIN pg_catalog.pg_class as c
+		ON c.oid = ivm.immvrelid
+		JOIN pg_catalog.pg_namespace as n
+		ON c.relnamespace = n.oid;
+END
+$$;
+
 CREATE FUNCTION pgivm.refresh_query_strings()
 RETURNS event_trigger LANGUAGE plpgsql SECURITY DEFINER AS
 $$
@@ -14,7 +33,9 @@ BEGIN
 	UPDATE pgivm.pg_ivm_immv SET querystring = pgivm.get_immv_def(immvrelid);
 
 	-- Reset search path to the original value.
-	EXECUTE format('SET search_path = %s', old_search_path);
+	IF old_search_path != '' AND old_search_path != '""' THEN
+		EXECUTE format('SET search_path = %s', old_search_path);
+	END IF;
 END
 $$;
 

From 5b95cfddf4cd2711ca98d117e45fbc47bb7e4835 Mon Sep 17 00:00:00 2001
From: Adam Guo <adamguo@amazon.com>
Date: Thu, 27 Mar 2025 14:14:05 +0000
Subject: [PATCH 06/13] Formatting, naming, comments

---
 matview.c | 54 +++++++++++++++++++++++++++++++++++-------------------
 1 file changed, 35 insertions(+), 19 deletions(-)

diff --git a/matview.c b/matview.c
index 8854124..e6db540 100644
--- a/matview.c
+++ b/matview.c
@@ -233,7 +233,7 @@ static void clean_up_IVM_hash_entry(MV_TriggerHashEntry *entry, bool is_abort,
 static void setLastUpdateXid(Oid immv_oid, FullTransactionId xid);
 static FullTransactionId getLastUpdateXid(Oid immv_oid);
 
-static Query *recreate_immv_query(Relation matviewRel);
+static Query *update_immv_viewdef(Relation matviewRel);
 
 /* SQL callable functions */
 PG_FUNCTION_INFO_V1(IVM_immediate_before);
@@ -389,7 +389,18 @@ RefreshImmvByOid(Oid matviewOid, bool is_create, bool skipData,
 	systable_endscan(scan);
 	table_close(pgIvmImmv, NoLock);
 
-	viewQuery = recreate_immv_query(matviewRel);
+	/*
+	 * Recreate the Query tree from the query string to account for changing
+	 * base table OIDs (e.g. after dump/restore) or changing format of the Query
+	 * node (after pg_upgrade).
+	 *
+	 * No need to create the Query tree a second time if we are creating a new
+	 * IMMV.
+	 */
+	if (is_create)
+		viewQuery = get_immv_query(matviewRel);
+	else
+		viewQuery = update_immv_viewdef(matviewRel);
 
 	/* For IMMV, we need to rewrite matview query */
 	if (!skipData)
@@ -719,34 +730,36 @@ get_immv_query(Relation matviewRel)
 }
 
 /*
- * recreate_immv_query
+ * update_immv_viewdef
  *
- * Parse the querystring for this IMMV.  Update the viewdef column in
- * pg_ivm_immv and return the Query tree.
+ * Read the query string for this IMMV from pg_ivm_immv.  Parse the query string
+ * and update the viewdef column with the new Query tree.  Return the Query
+ * tree.
  */
 static Query *
-recreate_immv_query(Relation matviewRel)
+update_immv_viewdef(Relation matviewRel)
 {
-	Relation pgIvmImmv = table_open(PgIvmImmvRelationId(), AccessShareLock);
-	TupleDesc tupdesc = RelationGetDescr(pgIvmImmv);
-	SysScanDesc scan;
-	ScanKeyData key;
-	HeapTuple tup;
-	bool isnull;
+	CreateTableAsStmt *stmt;
 	Datum datum;
-	Query *query = NULL;
+	Datum values[Natts_pg_ivm_immv];
+	HeapTuple newtup = NULL;
+	HeapTuple tup;
 	IntoClause *into;
 	ParseState *pstate = NULL;
-	CreateTableAsStmt *stmt;
-	const char *querystring;
-	const char *relname;
-	const char *querytree;
+	Query *query = NULL;
+	Relation pgIvmImmv = table_open(PgIvmImmvRelationId(), AccessShareLock);
+	ScanKeyData key;
+	SysScanDesc scan;
+	TupleDesc tupdesc = RelationGetDescr(pgIvmImmv);
 
-	Datum values[Natts_pg_ivm_immv];
+	bool isnull;
 	bool nulls[Natts_pg_ivm_immv];
 	bool replaces[Natts_pg_ivm_immv];
-	HeapTuple newtup = NULL;
+	const char *querystring;
+	const char *querytree;
+	const char *relname;
 
+	/* Scan pg_ivm_immv for the given IMMV entry. */
 	ScanKeyInit(&key,
 			    Anum_pg_ivm_immv_immvrelid,
 				BTEqualStrategyNumber, F_OIDEQ,
@@ -763,10 +776,12 @@ recreate_immv_query(Relation matviewRel)
 		return NULL;
 	}
 
+	/* Read the query string column. */
 	datum = heap_getattr(tup, Anum_pg_ivm_immv_querystring, tupdesc, &isnull);
 	Assert(!isnull);
 	querystring = TextDatumGetCString(datum);
 
+	/* Parse the query string using the same logic as create_immv. */
 	relname = psprintf("%s.%s",
 					   get_namespace_name(get_rel_namespace(matviewRel->rd_id)),
 					   get_rel_name(matviewRel->rd_id));
@@ -779,6 +794,7 @@ recreate_immv_query(Relation matviewRel)
 	query = rewriteQueryForIMMV(query, into->colNames);
 	querytree = nodeToString((Node *) query);
 
+	/* Update the pg_ivm_immv tuple with the new query tree. */
 	memset(values, 0, sizeof(values));
 	memset(nulls, 0, sizeof(nulls));
 	memset(replaces, 0, sizeof(replaces));

From eefb16763e4a446978c6437e24bc38e19798effb Mon Sep 17 00:00:00 2001
From: Adam Guo <adamguo@amazon.com>
Date: Thu, 27 Mar 2025 14:46:07 +0000
Subject: [PATCH 07/13] Add warning to event trigger

---
 pg_ivm--1.10--1.11.sql | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/pg_ivm--1.10--1.11.sql b/pg_ivm--1.10--1.11.sql
index 4f99101..bff5179 100644
--- a/pg_ivm--1.10--1.11.sql
+++ b/pg_ivm--1.10--1.11.sql
@@ -25,17 +25,25 @@ $$
 DECLARE
 	old_search_path text;
 BEGIN
-	-- Empty search path so that get_immv_def returns a fully-qualified query.
-	SELECT setting INTO old_search_path FROM pg_catalog.pg_settings
-		WHERE name = 'search_path';
-	SET search_path = '';
+	-- Only need to refresh query strings if an object is renamed.
+	-- As a rough heuristic, check if this is an ALTER command.
+	IF tg_tag LIKE 'ALTER %' THEN
+		-- Empty search path so that get_immv_def returns a fully-qualified query.
+		SELECT setting INTO old_search_path FROM pg_catalog.pg_settings
+			WHERE name = 'search_path';
+		SET search_path = '';
 
-	UPDATE pgivm.pg_ivm_immv SET querystring = pgivm.get_immv_def(immvrelid);
+		UPDATE pgivm.pg_ivm_immv SET querystring = pgivm.get_immv_def(immvrelid);
 
-	-- Reset search path to the original value.
-	IF old_search_path != '' AND old_search_path != '""' THEN
-		EXECUTE format('SET search_path = %s', old_search_path);
+		-- Reset search path to the original value.
+		IF old_search_path != '' AND old_search_path != '""' THEN
+			EXECUTE format('SET search_path = %s', old_search_path);
+		END IF;
 	END IF;
+EXCEPTION
+	WHEN internal_error THEN
+		RAISE WARNING 'pg_ivm could not refresh the pg_ivm_immv query strings.'
+			USING HINT = 'Please recreate your IMMVs using pgivm.recreate_all_immvs().';
 END
 $$;
 

From 1901c99f2169670aac8a82d88c176e7db6ec8172 Mon Sep 17 00:00:00 2001
From: Adam Guo <adamguo@amazon.com>
Date: Thu, 27 Mar 2025 18:15:22 +0000
Subject: [PATCH 08/13] Rollback GUC change in createas.c

---
 createas.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/createas.c b/createas.c
index 026cce3..338650d 100644
--- a/createas.c
+++ b/createas.c
@@ -1712,6 +1712,7 @@ StoreImmvQuery(Oid viewOid, Query *viewQuery)
 {
 	char   *querytree = nodeToString((Node *) viewQuery);
 	char   *querystring;
+	int		save_nestlevel;
 	Datum values[Natts_pg_ivm_immv];
 	bool isNulls[Natts_pg_ivm_immv];
 	Relation matviewRel;
@@ -1720,10 +1721,17 @@ StoreImmvQuery(Oid viewOid, Query *viewQuery)
 	HeapTuple heapTuple;
 	ObjectAddress	address;
 
+	/*
+	 * Restrict search_path so that pg_ivm_get_viewdef_internal returns a
+	 * fully-qualified query.
+	 */
+	save_nestlevel = NewGUCNestLevel();
 	RestrictSearchPath();
 	matviewRel = table_open(viewOid, AccessShareLock);
 	querystring = pg_ivm_get_viewdef_internal(viewQuery, matviewRel, true);
 	table_close(matviewRel, NoLock);
+	/* Roll back the search_path change. */
+	AtEOXact_GUC(false, save_nestlevel);
 
 	memset(values, 0, sizeof(values));
 	memset(isNulls, false, sizeof(isNulls));

From 38777f260aaf1eb8142a2f8f5db1b11accdbd4f7 Mon Sep 17 00:00:00 2001
From: Adam Guo <adamguo@amazon.com>
Date: Tue, 20 May 2025 19:16:55 +0000
Subject: [PATCH 09/13] Event trigger

---
 Makefile               |   3 +-
 event_trigger.c        | 237 +++++++++++++++++++++++++++++++++++++++++
 pg_ivm--1.10--1.11.sql |  36 ++-----
 pg_ivm.h               |   5 +
 4 files changed, 253 insertions(+), 28 deletions(-)
 create mode 100644 event_trigger.c

diff --git a/Makefile b/Makefile
index e225eaa..8ff11d3 100644
--- a/Makefile
+++ b/Makefile
@@ -9,7 +9,8 @@ OBJS = \
 	matview.o \
 	pg_ivm.o \
 	ruleutils.o \
-	subselect.o
+	subselect.o \
+	event_trigger.o
 PGFILEDESC = "pg_ivm - incremental view maintenance on PostgreSQL"
 
 EXTENSION = pg_ivm
diff --git a/event_trigger.c b/event_trigger.c
new file mode 100644
index 0000000..d23b4ac
--- /dev/null
+++ b/event_trigger.c
@@ -0,0 +1,237 @@
+#include "postgres.h"
+#include "pg_ivm.h"
+
+#include "access/table.h"
+#include "catalog/indexing.h"
+#include "commands/event_trigger.h"
+#include "utils/builtins.h"
+#include "utils/guc.h"
+#include "utils/lsyscache.h"
+#include "utils/memutils.h"
+#include "utils/rel.h"
+#include "utils/snapmgr.h"
+
+#define IMMV_INIT_QUERYHASHSIZE 16
+
+typedef struct HashEntry
+{
+	Oid			immv_relid;
+	char	   *query;
+}			HashEntry;
+
+/* Stores the Query nodes of each IMMV view query as they were pre-DDL. */
+static HTAB *immv_query_cache;
+
+/* Active snapshot at the time of the pre-DDL trigger. */
+static Snapshot active_snapshot;
+
+static char *retrieve_query(Oid immv_relid);
+static void hash_query(Oid immv_relid, char *query);
+static void initialize_query_cache(void);
+static void restore_query_strings_internal(void);
+static void save_query_strings_internal(void);
+
+PG_FUNCTION_INFO_V1(save_query_strings);
+PG_FUNCTION_INFO_V1(restore_query_strings);
+
+Datum
+save_query_strings(PG_FUNCTION_ARGS)
+{
+	EventTriggerData *trigdata;
+
+	if (!CALLED_AS_EVENT_TRIGGER(fcinfo))
+		ereport(ERROR, errmsg("not fired by event trigger manager"));
+
+	trigdata = (EventTriggerData *) fcinfo->context;
+
+	if (!IsA(trigdata->parsetree, RenameStmt))
+		PG_RETURN_NULL();
+
+	initialize_query_cache();
+	active_snapshot = GetActiveSnapshot();
+	save_query_strings_internal();
+
+	PG_RETURN_NULL();
+}
+
+Datum
+restore_query_strings(PG_FUNCTION_ARGS)
+{
+	EventTriggerData *trigdata;
+
+	if (!CALLED_AS_EVENT_TRIGGER(fcinfo))
+		ereport(ERROR, errmsg("not fired by event trigger manager"));
+
+	trigdata = (EventTriggerData *) fcinfo->context;
+
+	if (!IsA(trigdata->parsetree, RenameStmt))
+		PG_RETURN_NULL();
+
+	restore_query_strings_internal();
+
+	PG_RETURN_NULL();
+}
+
+static void
+initialize_query_cache(void)
+{
+	HASHCTL		ctl;
+
+	memset(&ctl, 0, sizeof(ctl));
+	ctl.keysize = sizeof(Oid);
+	ctl.entrysize = sizeof(HashEntry);
+	immv_query_cache = hash_create("IMMV query cache", IMMV_INIT_QUERYHASHSIZE,
+								   &ctl, HASH_ELEM | HASH_BLOBS);
+}
+
+static void
+hash_query(Oid immv_relid, char *query)
+{
+	HashEntry  *entry;
+	MemoryContext old_cxt;
+	bool		found;
+
+	entry = (HashEntry *) hash_search(immv_query_cache,
+									  &immv_relid,
+									  HASH_ENTER,
+									  &found);
+	Assert(!found);
+
+	old_cxt = MemoryContextSwitchTo(TopTransactionContext);
+	entry->query = pstrdup(query);
+	MemoryContextSwitchTo(old_cxt);
+}
+
+static char *
+retrieve_query(Oid immv_relid)
+{
+	HashEntry  *entry;
+	MemoryContext old_cxt;
+	bool		found;
+	char	   *query;
+
+	entry = (HashEntry *) hash_search(immv_query_cache,
+									  &immv_relid,
+									  HASH_FIND,
+									  &found);
+	Assert(found);
+
+	old_cxt = MemoryContextSwitchTo(TopTransactionContext);
+	query = pstrdup(entry->query);
+	pfree(entry->query);
+	MemoryContextSwitchTo(old_cxt);
+
+	return query;
+}
+
+static void
+save_query_strings_internal(void)
+{
+	HeapTuple	tup;
+	Relation	pg_ivm_immv_rel;
+	SysScanDesc scan;
+	TupleDesc	tupdesc;
+
+	pg_ivm_immv_rel = table_open(PgIvmImmvRelationId(), RowExclusiveLock);
+	scan = systable_beginscan(pg_ivm_immv_rel, PgIvmImmvPrimaryKeyIndexId(),
+							  true, active_snapshot, 0, NULL);
+	tupdesc = RelationGetDescr(pg_ivm_immv_rel);
+
+	while ((tup = systable_getnext(scan)) != NULL)
+	{
+		Oid			matview_oid;
+		ParseState *parse_state;
+		Query	   *query;
+		bool		isnull;
+		char	   *matview_relname;
+		char	   *query_string;
+
+		query_string = TextDatumGetCString(heap_getattr(tup,
+														Anum_pg_ivm_immv_querystring,
+														tupdesc, &isnull));
+		Assert(!isnull);
+
+		matview_oid = DatumGetObjectId(heap_getattr(tup, Anum_pg_ivm_immv_immvrelid,
+													tupdesc, &isnull));
+		Assert(!isnull);
+
+		matview_relname = psprintf("%s.%s",
+								   get_namespace_name(get_rel_namespace(matview_oid)),
+								   get_rel_name(matview_oid));
+
+		/* Parse the existing IMMV query pre-DDL.  Add it to the list. */
+		parse_immv_query(matview_relname, query_string, &query, &parse_state);
+
+		/* Store entry for this IMMV. */
+		hash_query(matview_oid, nodeToString(query));
+	}
+
+	systable_endscan(scan);
+	table_close(pg_ivm_immv_rel, NoLock);
+}
+
+static void
+restore_query_strings_internal(void)
+{
+	HeapTuple	tup;
+	Relation	pg_ivm_immv_rel;
+	SysScanDesc scan;
+	TupleDesc	tupdesc;
+	int			save_nestlevel;
+
+	pg_ivm_immv_rel = table_open(PgIvmImmvRelationId(), RowExclusiveLock);
+	scan = systable_beginscan(pg_ivm_immv_rel, PgIvmImmvPrimaryKeyIndexId(),
+							  true, active_snapshot, 0, NULL);
+	tupdesc = RelationGetDescr(pg_ivm_immv_rel);
+
+	/*
+	 * Restrict search_path so that pg_ivm_get_viewdef_internal returns a
+	 * fully-qualified query.
+	 */
+	save_nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+
+	while ((tup = systable_getnext(scan)) != NULL)
+	{
+		Datum		values[Natts_pg_ivm_immv];
+		HeapTuple	newtup;
+		Oid			matview_oid;
+		Query	   *query;
+		Relation	matview_rel;
+		bool		isnull;
+		bool		nulls[Natts_pg_ivm_immv];
+		bool		replaces[Natts_pg_ivm_immv];
+		char	   *new_query_string;
+		char	   *serialized_query;
+
+		matview_oid = DatumGetObjectId(heap_getattr(tup, Anum_pg_ivm_immv_immvrelid,
+													tupdesc, &isnull));
+		Assert(!isnull);
+
+		serialized_query = retrieve_query(matview_oid);
+		query = stringToNode(serialized_query);
+		query = (Query *) ((CreateTableAsStmt *) query->utilityStmt)->into->viewQuery;
+
+		matview_rel = table_open(matview_oid, AccessShareLock);
+		new_query_string = pg_ivm_get_viewdef_internal(query, matview_rel, true);
+		table_close(matview_rel, NoLock);
+
+		memset(values, 0, sizeof(values));
+		values[Anum_pg_ivm_immv_querystring - 1] = CStringGetTextDatum(new_query_string);
+		memset(nulls, false, sizeof(nulls));
+		memset(replaces, false, sizeof(nulls));
+		replaces[Anum_pg_ivm_immv_querystring - 1] = true;
+
+		newtup = heap_modify_tuple(tup, tupdesc, values, nulls, replaces);
+
+		CatalogTupleUpdate(pg_ivm_immv_rel, &newtup->t_self, newtup);
+		heap_freetuple(newtup);
+	}
+
+	systable_endscan(scan);
+	table_close(pg_ivm_immv_rel, NoLock);
+	hash_destroy(immv_query_cache);
+
+	/* Roll back the search_path change. */
+	AtEOXact_GUC(false, save_nestlevel);
+}
diff --git a/pg_ivm--1.10--1.11.sql b/pg_ivm--1.10--1.11.sql
index bff5179..c5aeaca 100644
--- a/pg_ivm--1.10--1.11.sql
+++ b/pg_ivm--1.10--1.11.sql
@@ -19,34 +19,16 @@ BEGIN
 END
 $$;
 
-CREATE FUNCTION pgivm.refresh_query_strings()
-RETURNS event_trigger LANGUAGE plpgsql SECURITY DEFINER AS
-$$
-DECLARE
-	old_search_path text;
-BEGIN
-	-- Only need to refresh query strings if an object is renamed.
-	-- As a rough heuristic, check if this is an ALTER command.
-	IF tg_tag LIKE 'ALTER %' THEN
-		-- Empty search path so that get_immv_def returns a fully-qualified query.
-		SELECT setting INTO old_search_path FROM pg_catalog.pg_settings
-			WHERE name = 'search_path';
-		SET search_path = '';
+CREATE FUNCTION pgivm.save_query_strings() RETURNS event_trigger
+AS 'MODULE_PATHNAME', 'save_query_strings' LANGUAGE C;
 
-		UPDATE pgivm.pg_ivm_immv SET querystring = pgivm.get_immv_def(immvrelid);
+CREATE FUNCTION pgivm.restore_query_strings() RETURNS event_trigger
+AS 'MODULE_PATHNAME', 'restore_query_strings' LANGUAGE C;
 
-		-- Reset search path to the original value.
-		IF old_search_path != '' AND old_search_path != '""' THEN
-			EXECUTE format('SET search_path = %s', old_search_path);
-		END IF;
-	END IF;
-EXCEPTION
-	WHEN internal_error THEN
-		RAISE WARNING 'pg_ivm could not refresh the pg_ivm_immv query strings.'
-			USING HINT = 'Please recreate your IMMVs using pgivm.recreate_all_immvs().';
-END
-$$;
+CREATE EVENT TRIGGER save_query_strings
+ON ddl_command_start
+EXECUTE FUNCTION pgivm.save_query_strings();
 
-CREATE EVENT TRIGGER refresh_query_strings
+CREATE EVENT TRIGGER restore_query_strings
 ON ddl_command_end
-EXECUTE FUNCTION pgivm.refresh_query_strings();
+EXECUTE FUNCTION pgivm.restore_query_strings();
diff --git a/pg_ivm.h b/pg_ivm.h
index 04c83f0..c8b29c6 100644
--- a/pg_ivm.h
+++ b/pg_ivm.h
@@ -72,6 +72,11 @@ extern char *pg_ivm_get_viewdef_internal(Query *query, Relation immvrel, bool pr
 /* subselect.c */
 extern void inline_cte(PlannerInfo *root, CommonTableExpr *cte);
 
+/* event_trigger.c */
+
+extern Datum save_query_string(PG_FUNCTION_ARGS);
+extern Datum restore_query_string(PG_FUNCTION_ARGS);
+
 #if defined(PG_VERSION_NUM) && (PG_VERSION_NUM < 170000)
 extern void RestrictSearchPath(void);
 #endif

From 5a31d7a9ad1901ec7edab66cbbd52ea0e7057357 Mon Sep 17 00:00:00 2001
From: Adam Guo <adamguo@amazon.com>
Date: Mon, 19 May 2025 16:22:52 +0000
Subject: [PATCH 10/13] Add UUID column to pg_ivm_immv.

---
 createas.c             | 89 +++++++++++++++++++++++-------------------
 matview.c              | 29 +++++++++-----
 pg_ivm--1.10--1.11.sql |  2 +
 pg_ivm.c               | 86 ++++++++++++++++++++++++++++++++++++++++
 pg_ivm.h               | 17 ++++++--
 5 files changed, 169 insertions(+), 54 deletions(-)

diff --git a/createas.c b/createas.c
index 338650d..10a09c0 100644
--- a/createas.c
+++ b/createas.c
@@ -62,8 +62,8 @@ typedef struct
 } DR_intorel;
 
 /* utility functions for IMMV definition creation */
-static ObjectAddress create_immv_internal(List *attrList, IntoClause *into);
-static ObjectAddress create_immv_nodata(List *tlist, IntoClause *into);
+static ImmvAddress create_immv_internal(List *attrList, IntoClause *into);
+static ImmvAddress create_immv_nodata(List *tlist, IntoClause *into);
 
 typedef struct
 {
@@ -74,15 +74,15 @@ typedef struct
 	int		sublevels_up;		/* (current) nesting depth */
 } check_ivm_restriction_context;
 
-static void CreateIvmTriggersOnBaseTablesRecurse(Query *qry, Node *node, Oid matviewOid,
+static void CreateIvmTriggersOnBaseTablesRecurse(Query *qry, Node *node, ImmvAddress immv_addr,
 									 Relids *relids, bool ex_lock);
-static void CreateIvmTrigger(Oid relOid, Oid viewOid, int16 type, int16 timing, bool ex_lock);
+static void CreateIvmTrigger(Oid relOid, ImmvAddress immv_addr, int16 type, int16 timing, bool ex_lock);
 static void check_ivm_restriction(Node *node);
 static bool check_ivm_restriction_walker(Node *node, check_ivm_restriction_context *context);
 static Bitmapset *get_primary_key_attnos_from_query(Query *query, List **constraintList);
 static bool check_aggregate_supports_ivm(Oid aggfnoid);
 
-static void StoreImmvQuery(Oid viewOid, Query *viewQuery);
+static void StoreImmvQuery(ImmvAddress immv_addr, Query *viewQuery);
 
 #if defined(PG_VERSION_NUM) && (PG_VERSION_NUM < 140000)
 static bool CreateTableAsRelExists(CreateTableAsStmt *ctas);
@@ -96,14 +96,15 @@ static bool CreateTableAsRelExists(CreateTableAsStmt *ctas);
  *
  * This imitates PostgreSQL's create_ctas_internal().
  */
-static ObjectAddress
+static ImmvAddress
 create_immv_internal(List *attrList, IntoClause *into)
 {
 	CreateStmt *create = makeNode(CreateStmt);
 	char		relkind;
 	Datum		toast_options;
 	static char *validnsps[] = HEAP_RELOPT_NAMESPACES;
-	ObjectAddress intoRelationAddr;
+	ImmvAddress	immv_addr;
+	pg_uuid_t	*immv_uuid;
 
 	/* This code supports both CREATE TABLE AS and CREATE MATERIALIZED VIEW */
 	/* relkind of IMMV must be RELKIND_RELATION */
@@ -128,7 +129,12 @@ create_immv_internal(List *attrList, IntoClause *into)
 	 * Create the relation.  (This will error out if there's an existing view,
 	 * so we don't need more code to complain if "replace" is false.)
 	 */
-	intoRelationAddr = DefineRelation(create, relkind, InvalidOid, NULL, NULL);
+	immv_addr.address = DefineRelation(create, relkind, InvalidOid, NULL, NULL);
+	/* Generate the IMMV UUID. */
+	// TODO: check for hash collision
+	immv_uuid = DatumGetUUIDP(DirectFunctionCall1(gen_random_uuid, (Datum) NULL));
+	memcpy(&immv_addr.immv_uuid, immv_uuid, sizeof(*immv_uuid));
+	pfree(immv_uuid);
 
 	/*
 	 * If necessary, create a TOAST table for the target table.  Note that
@@ -146,13 +152,13 @@ create_immv_internal(List *attrList, IntoClause *into)
 
 	(void) heap_reloptions(RELKIND_TOASTVALUE, toast_options, true);
 
-	NewRelationCreateToastTable(intoRelationAddr.objectId, toast_options);
+	NewRelationCreateToastTable(immv_addr.address.objectId, toast_options);
 
 	/* Create the "view" part of an IMMV. */
-	StoreImmvQuery(intoRelationAddr.objectId, (Query *) into->viewQuery);
+	StoreImmvQuery(immv_addr, (Query *) into->viewQuery);
 	CommandCounterIncrement();
 
-	return intoRelationAddr;
+	return immv_addr;
 }
 
 /*
@@ -163,7 +169,7 @@ create_immv_internal(List *attrList, IntoClause *into)
  *
  * This imitates PostgreSQL's create_ctas_nodata().
  */
-static ObjectAddress
+static ImmvAddress
 create_immv_nodata(List *tlist, IntoClause *into)
 {
 	List	   *attrList;
@@ -240,7 +246,7 @@ ExecCreateImmv(ParseState *pstate, CreateTableAsStmt *stmt,
 	Query	   *query = castNode(Query, stmt->query);
 	IntoClause *into = stmt->into;
 	bool		do_refresh = false;
-	ObjectAddress address;
+	ImmvAddress	immv_addr;
 
 	/* Check if the relation exists or not */
 	if (CreateTableAsRelExists(stmt))
@@ -275,7 +281,7 @@ ExecCreateImmv(ParseState *pstate, CreateTableAsStmt *stmt,
 	 * similar to CREATE VIEW.  This avoids dump/restore problems stemming
 	 * from running the planner before all dependencies are set up.
 	 */
-	address = create_immv_nodata(query->targetList, into);
+	immv_addr = create_immv_nodata(query->targetList, into);
 
 	/*
 	 * For materialized views, reuse the REFRESH logic, which locks down
@@ -286,18 +292,18 @@ ExecCreateImmv(ParseState *pstate, CreateTableAsStmt *stmt,
 	{
 		Relation matviewRel;
 
-		RefreshImmvByOid(address.objectId, true, false, pstate->p_sourcetext, qc);
+		RefreshImmvByOid(immv_addr, true, false, pstate->p_sourcetext, qc);
 
 		if (qc)
 			qc->commandTag = CMDTAG_SELECT;
 
-		matviewRel = table_open(address.objectId, NoLock);
+		matviewRel = table_open(immv_addr.address.objectId, NoLock);
 
 		/* Create an index on incremental maintainable materialized view, if possible */
 		CreateIndexOnIMMV(query, matviewRel);
 
 		/* Create triggers to prevent IMMV from being changed */
-		CreateChangePreventTrigger(address.objectId);
+		CreateChangePreventTrigger(immv_addr.address.objectId);
 
 		table_close(matviewRel, NoLock);
 
@@ -309,7 +315,7 @@ ExecCreateImmv(ParseState *pstate, CreateTableAsStmt *stmt,
 							 "or execute refresh_immv to make sure the view is consistent.")));
 	}
 
-	return address;
+	return immv_addr.address;
 }
 
 /*
@@ -548,7 +554,7 @@ makeIvmAggColumn(ParseState *pstate, Aggref *aggref, char *resname, AttrNumber *
  * CreateIvmTriggersOnBaseTables -- create IVM triggers on all base tables
  */
 void
-CreateIvmTriggersOnBaseTables(Query *qry, Oid matviewOid)
+CreateIvmTriggersOnBaseTables(Query *qry, ImmvAddress immv_addr)
 {
 	Relids	relids = NULL;
 	bool	ex_lock = false;
@@ -582,13 +588,13 @@ CreateIvmTriggersOnBaseTables(Query *qry, Oid matviewOid)
 		qry->distinctClause || (qry->hasAggs && qry->groupClause))
 		ex_lock = true;
 
-	CreateIvmTriggersOnBaseTablesRecurse(qry, (Node *)qry, matviewOid, &relids, ex_lock);
+	CreateIvmTriggersOnBaseTablesRecurse(qry, (Node *)qry, immv_addr, &relids, ex_lock);
 
 	bms_free(relids);
 }
 
 static void
-CreateIvmTriggersOnBaseTablesRecurse(Query *qry, Node *node, Oid matviewOid,
+CreateIvmTriggersOnBaseTablesRecurse(Query *qry, Node *node, ImmvAddress immv_addr,
 									 Relids *relids, bool ex_lock)
 {
 	if (node == NULL)
@@ -604,12 +610,12 @@ CreateIvmTriggersOnBaseTablesRecurse(Query *qry, Node *node, Oid matviewOid,
 				Query *query = (Query *) node;
 				ListCell *lc;
 
-				CreateIvmTriggersOnBaseTablesRecurse(qry, (Node *) query->jointree, matviewOid, relids, ex_lock);
+				CreateIvmTriggersOnBaseTablesRecurse(qry, (Node *) query->jointree, immv_addr, relids, ex_lock);
 				foreach(lc, query->cteList)
 				{
 					CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
 					Assert(IsA(cte->ctequery, Query));
-					CreateIvmTriggersOnBaseTablesRecurse((Query *) cte->ctequery, cte->ctequery, matviewOid, relids, ex_lock);
+					CreateIvmTriggersOnBaseTablesRecurse((Query *) cte->ctequery, cte->ctequery, immv_addr, relids, ex_lock);
 				}
 			}
 			break;
@@ -621,14 +627,14 @@ CreateIvmTriggersOnBaseTablesRecurse(Query *qry, Node *node, Oid matviewOid,
 
 				if (rte->rtekind == RTE_RELATION && !bms_is_member(rte->relid, *relids))
 				{
-					CreateIvmTrigger(rte->relid, matviewOid, TRIGGER_TYPE_INSERT, TRIGGER_TYPE_BEFORE, ex_lock);
-					CreateIvmTrigger(rte->relid, matviewOid, TRIGGER_TYPE_DELETE, TRIGGER_TYPE_BEFORE, ex_lock);
-					CreateIvmTrigger(rte->relid, matviewOid, TRIGGER_TYPE_UPDATE, TRIGGER_TYPE_BEFORE, ex_lock);
-					CreateIvmTrigger(rte->relid, matviewOid, TRIGGER_TYPE_TRUNCATE, TRIGGER_TYPE_BEFORE, true);
-					CreateIvmTrigger(rte->relid, matviewOid, TRIGGER_TYPE_INSERT, TRIGGER_TYPE_AFTER, ex_lock);
-					CreateIvmTrigger(rte->relid, matviewOid, TRIGGER_TYPE_DELETE, TRIGGER_TYPE_AFTER, ex_lock);
-					CreateIvmTrigger(rte->relid, matviewOid, TRIGGER_TYPE_UPDATE, TRIGGER_TYPE_AFTER, ex_lock);
-					CreateIvmTrigger(rte->relid, matviewOid, TRIGGER_TYPE_TRUNCATE, TRIGGER_TYPE_AFTER, true);
+					CreateIvmTrigger(rte->relid, immv_addr, TRIGGER_TYPE_INSERT, TRIGGER_TYPE_BEFORE, ex_lock);
+					CreateIvmTrigger(rte->relid, immv_addr, TRIGGER_TYPE_DELETE, TRIGGER_TYPE_BEFORE, ex_lock);
+					CreateIvmTrigger(rte->relid, immv_addr, TRIGGER_TYPE_UPDATE, TRIGGER_TYPE_BEFORE, ex_lock);
+					CreateIvmTrigger(rte->relid, immv_addr, TRIGGER_TYPE_TRUNCATE, TRIGGER_TYPE_BEFORE, true);
+					CreateIvmTrigger(rte->relid, immv_addr, TRIGGER_TYPE_INSERT, TRIGGER_TYPE_AFTER, ex_lock);
+					CreateIvmTrigger(rte->relid, immv_addr, TRIGGER_TYPE_DELETE, TRIGGER_TYPE_AFTER, ex_lock);
+					CreateIvmTrigger(rte->relid, immv_addr, TRIGGER_TYPE_UPDATE, TRIGGER_TYPE_AFTER, ex_lock);
+					CreateIvmTrigger(rte->relid, immv_addr, TRIGGER_TYPE_TRUNCATE, TRIGGER_TYPE_AFTER, true);
 
 					*relids = bms_add_member(*relids, rte->relid);
 				}
@@ -636,7 +642,7 @@ CreateIvmTriggersOnBaseTablesRecurse(Query *qry, Node *node, Oid matviewOid,
 				{
 					Query *subquery = rte->subquery;
 					Assert(rte->subquery != NULL);
-					CreateIvmTriggersOnBaseTablesRecurse(subquery, (Node *) subquery, matviewOid, relids, ex_lock);
+					CreateIvmTriggersOnBaseTablesRecurse(subquery, (Node *) subquery, immv_addr, relids, ex_lock);
 				}
 			}
 			break;
@@ -647,7 +653,7 @@ CreateIvmTriggersOnBaseTablesRecurse(Query *qry, Node *node, Oid matviewOid,
 				ListCell   *l;
 
 				foreach(l, f->fromlist)
-					CreateIvmTriggersOnBaseTablesRecurse(qry, lfirst(l), matviewOid, relids, ex_lock);
+					CreateIvmTriggersOnBaseTablesRecurse(qry, lfirst(l), immv_addr, relids, ex_lock);
 			}
 			break;
 
@@ -655,8 +661,8 @@ CreateIvmTriggersOnBaseTablesRecurse(Query *qry, Node *node, Oid matviewOid,
 			{
 				JoinExpr   *j = (JoinExpr *) node;
 
-				CreateIvmTriggersOnBaseTablesRecurse(qry, j->larg, matviewOid, relids, ex_lock);
-				CreateIvmTriggersOnBaseTablesRecurse(qry, j->rarg, matviewOid, relids, ex_lock);
+				CreateIvmTriggersOnBaseTablesRecurse(qry, j->larg, immv_addr, relids, ex_lock);
+				CreateIvmTriggersOnBaseTablesRecurse(qry, j->rarg, immv_addr, relids, ex_lock);
 			}
 			break;
 
@@ -669,7 +675,7 @@ CreateIvmTriggersOnBaseTablesRecurse(Query *qry, Node *node, Oid matviewOid,
  * CreateIvmTrigger -- create IVM trigger on a base table
  */
 static void
-CreateIvmTrigger(Oid relOid, Oid viewOid, int16 type, int16 timing, bool ex_lock)
+CreateIvmTrigger(Oid relOid, ImmvAddress immv_addr, int16 type, int16 timing, bool ex_lock)
 {
 	ObjectAddress	refaddr;
 	ObjectAddress	address;
@@ -679,7 +685,7 @@ CreateIvmTrigger(Oid relOid, Oid viewOid, int16 type, int16 timing, bool ex_lock
 	Assert(timing == TRIGGER_TYPE_BEFORE || timing == TRIGGER_TYPE_AFTER);
 
 	refaddr.classId = RelationRelationId;
-	refaddr.objectId = viewOid;
+	refaddr.objectId = immv_addr.address.objectId;
 	refaddr.objectSubId = 0;
 
 	ivm_trigger = makeNode(CreateTrigStmt);
@@ -753,7 +759,7 @@ CreateIvmTrigger(Oid relOid, Oid viewOid, int16 type, int16 timing, bool ex_lock
 	ivm_trigger->initdeferred = false;
 	ivm_trigger->constrrel = NULL;
 	ivm_trigger->args = list_make2(
-		makeString(DatumGetPointer(DirectFunctionCall1(oidout, ObjectIdGetDatum(viewOid)))),
+		makeString(DatumGetPointer(UUIDPGetDatum(&immv_addr.immv_uuid))),
 		makeString(DatumGetPointer(DirectFunctionCall1(boolout, BoolGetDatum(ex_lock))))
 		);
 
@@ -1708,7 +1714,7 @@ get_primary_key_attnos_from_query(Query *query, List **constraintList)
  * Store the query for the IMMV to pg_ivm_immv
  */
 static void
-StoreImmvQuery(Oid viewOid, Query *viewQuery)
+StoreImmvQuery(ImmvAddress immv_addr, Query *viewQuery)
 {
 	char   *querytree = nodeToString((Node *) viewQuery);
 	char   *querystring;
@@ -1736,10 +1742,11 @@ StoreImmvQuery(Oid viewOid, Query *viewQuery)
 	memset(values, 0, sizeof(values));
 	memset(isNulls, false, sizeof(isNulls));
 
-	values[Anum_pg_ivm_immv_immvrelid -1 ] = ObjectIdGetDatum(viewOid);
+	values[Anum_pg_ivm_immv_immvrelid -1 ] = ObjectIdGetDatum(immv_addr.address.objectId);
 	values[Anum_pg_ivm_immv_ispopulated -1 ] = BoolGetDatum(false);
 	values[Anum_pg_ivm_immv_viewdef -1 ] = CStringGetTextDatum(querytree);
 	values[Anum_pg_ivm_immv_querystring - 1] = CStringGetTextDatum(querystring);
+	values[Anum_pg_ivm_immv_immvuuid -1 ] = UUIDPGetDatum(&immv_addr.immv_uuid);
 
 	pgIvmImmv = table_open(PgIvmImmvRelationId(), RowExclusiveLock);
 
@@ -1749,7 +1756,7 @@ StoreImmvQuery(Oid viewOid, Query *viewQuery)
 	CatalogTupleInsert(pgIvmImmv, heapTuple);
 
 	address.classId = RelationRelationId;
-	address.objectId = viewOid;
+	address.objectId = immv_addr.address.objectId;
 	address.objectSubId = 0;
 
 	recordDependencyOnExpr(&address, (Node *) viewQuery, NIL,
diff --git a/matview.c b/matview.c
index e6db540..b42001c 100644
--- a/matview.c
+++ b/matview.c
@@ -50,6 +50,7 @@
 #include "utils/rel.h"
 #include "utils/snapmgr.h"
 #include "utils/typcache.h"
+#include "utils/uuid.h"
 #include "utils/xid8.h"
 
 #include "pg_ivm.h"
@@ -251,6 +252,7 @@ ExecRefreshImmv(const RangeVar *relation, bool skipData,
 {
 	Oid			matviewOid;
 	LOCKMODE	lockmode;
+	ImmvAddress	immv_addr;
 
 	/* Determine strength of lock needed. */
 	//concurrent = stmt->concurrent;
@@ -272,7 +274,12 @@ ExecRefreshImmv(const RangeVar *relation, bool skipData,
 										  NULL);
 #endif
 
-	return RefreshImmvByOid(matviewOid, false, skipData, queryString, qc);
+	immv_addr.address.classId = RelationRelationId;
+	immv_addr.address.objectId = matviewOid;
+	immv_addr.address.objectSubId = 0;
+
+	// TODO: get uuid
+	return RefreshImmvByOid(immv_addr, false, skipData, queryString, qc);
 }
 
 /*
@@ -283,7 +290,7 @@ ExecRefreshImmv(const RangeVar *relation, bool skipData,
  * This imitates PostgreSQL's RefreshMatViewByOid().
  */
 ObjectAddress
-RefreshImmvByOid(Oid matviewOid, bool is_create, bool skipData,
+RefreshImmvByOid(ImmvAddress immv_addr, bool is_create, bool skipData,
 				 const char *queryString, QueryCompletion *qc)
 {
 	Relation	matviewRel;
@@ -300,6 +307,7 @@ RefreshImmvByOid(Oid matviewOid, bool is_create, bool skipData,
 	int			save_nestlevel;
 	ObjectAddress address;
 	bool oldPopulated;
+	Oid			matviewOid = immv_addr.address.objectId;
 
 	Relation pgIvmImmv;
 	TupleDesc tupdesc;
@@ -486,10 +494,7 @@ RefreshImmvByOid(Oid matviewOid, bool is_create, bool skipData,
 	 * is created.
 	 */
 	if (!skipData && !oldPopulated)
-	{
-		CreateIvmTriggersOnBaseTables(dataQuery, matviewOid);
-		CreateChangePreventTrigger(matviewOid);
-	}
+		CreateIvmTriggersOnBaseTables(dataQuery, immv_addr);
 
 	/*
 	 * Create the transient table that will receive the regenerated data. Lock
@@ -844,15 +849,17 @@ Datum
 IVM_immediate_before(PG_FUNCTION_ARGS)
 {
 	TriggerData *trigdata = (TriggerData *) fcinfo->context;
-	char	   *matviewOid_text = trigdata->tg_trigger->tgargs[0];
+	char	   *immv_uuid_text = trigdata->tg_trigger->tgargs[0];
 	char	   *ex_lock_text = trigdata->tg_trigger->tgargs[1];
+	pg_uuid_t  *immv_uuid;
 	Oid			matviewOid;
 	MV_TriggerHashEntry *entry;
 	bool	found;
 	bool	ex_lock;
 
-	matviewOid = DatumGetObjectId(DirectFunctionCall1(oidin, CStringGetDatum(matviewOid_text)));
+	immv_uuid = DatumGetUUIDP(CStringGetDatum(immv_uuid_text));
 	ex_lock = DatumGetBool(DirectFunctionCall1(boolin, CStringGetDatum(ex_lock_text)));
+	matviewOid = GetImmvRelid(immv_uuid);
 
 	/* If the view has more than one tables, we have to use an exclusive lock. */
 	if (ex_lock)
@@ -967,10 +974,11 @@ IVM_immediate_maintenance(PG_FUNCTION_ARGS)
 	Oid			matviewOid;
 	Query	   *query;
 	Query	   *rewritten = NULL;
-	char	   *matviewOid_text = trigdata->tg_trigger->tgargs[0];
+	char	   *immv_uuid_text = trigdata->tg_trigger->tgargs[0];
 	Relation	matviewRel;
 	int old_depth = immv_maintenance_depth;
 	SubTransactionId subxid;
+	pg_uuid_t  *immv_uuid;
 
 	Oid			relowner;
 	Tuplestorestate *old_tuplestore = NULL;
@@ -998,7 +1006,8 @@ IVM_immediate_maintenance(PG_FUNCTION_ARGS)
 	rel = trigdata->tg_relation;
 	relid = rel->rd_id;
 
-	matviewOid = DatumGetObjectId(DirectFunctionCall1(oidin, CStringGetDatum(matviewOid_text)));
+	immv_uuid = DatumGetUUIDP(CStringGetDatum(immv_uuid_text));
+	matviewOid = GetImmvRelid(immv_uuid);
 
 	/*
 	 * On the first call initialize the hashtable
diff --git a/pg_ivm--1.10--1.11.sql b/pg_ivm--1.10--1.11.sql
index c5aeaca..1e718de 100644
--- a/pg_ivm--1.10--1.11.sql
+++ b/pg_ivm--1.10--1.11.sql
@@ -1,4 +1,6 @@
 ALTER TABLE pgivm.pg_ivm_immv ADD COLUMN querystring text NOT NULL;
+ALTER TABLE pgivm.pg_ivm_immv ADD COLUMN immvuuid uuid NOT NULL;
+ALTER TABLE pgivm.pg_ivm_immv ADD CONSTRAINT pg_ivm_immv_uuid UNIQUE (immvuuid);
 
 CREATE FUNCTION pgivm.recreate_all_immvs() RETURNS VOID LANGUAGE PLPGSQL AS
 $$
diff --git a/pg_ivm.c b/pg_ivm.c
index a005e07..6b8e1d4 100644
--- a/pg_ivm.c
+++ b/pg_ivm.c
@@ -32,6 +32,7 @@
 #include "utils/lsyscache.h"
 #include "utils/regproc.h"
 #include "utils/rel.h"
+#include "utils/uuid.h"
 #include "utils/varlena.h"
 
 #include "pg_ivm.h"
@@ -365,6 +366,17 @@ PgIvmImmvPrimaryKeyIndexId(void)
 		AccessShareLock, true);
 }
 
+/*
+ * Get relid of pg_ivm_immv's UUID unique key.
+ */
+Oid
+PgIvmImmvUuidIndexId(void)
+{
+	return RangeVarGetRelid(
+		makeRangeVar("pgivm", "pg_ivm_immv_uuid", -1),
+		AccessShareLock, true);
+}
+
 /*
  * Return the SELECT part of an IMMV
  */
@@ -488,3 +500,77 @@ RestrictSearchPath(void)
 					  PGC_S_SESSION, GUC_ACTION_SAVE, true, 0, false);
 }
 #endif
+
+/*
+ * GetImmvOid
+ *
+ * Look up the immvrelid of an IMMV from its immv_uuid.
+ */
+Oid
+GetImmvRelid(pg_uuid_t *immv_uuid)
+{
+	Datum datum;
+	HeapTuple tup;
+	Relation pgIvmImmv = table_open(PgIvmImmvRelationId(), AccessShareLock);
+	ScanKeyData key;
+	SysScanDesc scan;
+	TupleDesc tupdesc = RelationGetDescr(pgIvmImmv);
+	bool isnull;
+
+	ScanKeyInit(&key, Anum_pg_ivm_immv_immvuuid, BTEqualStrategyNumber,
+				F_UUID_EQ, UUIDPGetDatum(immv_uuid));
+	scan = systable_beginscan(pgIvmImmv, PgIvmImmvUuidIndexId(), true, NULL, 1,
+							  &key);
+	tup = systable_getnext(scan);
+
+	if (!HeapTupleIsValid(tup))
+	{
+		systable_endscan(scan);
+		table_close(pgIvmImmv, NoLock);
+		return InvalidOid;
+	}
+
+	datum = heap_getattr(tup, Anum_pg_ivm_immv_immvrelid, tupdesc, &isnull);
+	Assert(!isnull);
+
+	systable_endscan(scan);
+	table_close(pgIvmImmv, NoLock);
+	return DatumGetObjectId(datum);
+}
+
+/*
+ * GetImmvUuid
+ *
+ * Look up the immv_uuid of an IMMV from its immvrelid.
+ */
+pg_uuid_t *
+GetImmvUuid(Oid immvrelid)
+{
+	Datum datum;
+	HeapTuple tup;
+	Relation pgIvmImmv = table_open(PgIvmImmvRelationId(), AccessShareLock);
+	ScanKeyData key;
+	SysScanDesc scan;
+	TupleDesc tupdesc = RelationGetDescr(pgIvmImmv);
+	bool isnull;
+
+	ScanKeyInit(&key, Anum_pg_ivm_immv_immvrelid, BTEqualStrategyNumber, F_OIDEQ,
+			ObjectIdGetDatum(immvrelid));
+	scan = systable_beginscan(pgIvmImmv, PgIvmImmvPrimaryKeyIndexId(),
+			true, NULL, 1, &key);
+	tup = systable_getnext(scan);
+
+	if (!HeapTupleIsValid(tup))
+	{
+		systable_endscan(scan);
+		table_close(pgIvmImmv, NoLock);
+		return NULL;
+	}
+
+	datum = heap_getattr(tup, Anum_pg_ivm_immv_immvuuid, tupdesc, &isnull);
+	Assert(!isnull);
+
+	systable_endscan(scan);
+	table_close(pgIvmImmv, NoLock);
+	return DatumGetUUIDP(datum);
+}
diff --git a/pg_ivm.h b/pg_ivm.h
index c8b29c6..d8f80f9 100644
--- a/pg_ivm.h
+++ b/pg_ivm.h
@@ -19,30 +19,41 @@
 #include "parser/parse_node.h"
 #include "tcop/dest.h"
 #include "utils/queryenvironment.h"
+#include "utils/uuid.h"
 
-#define Natts_pg_ivm_immv 5
+#define Natts_pg_ivm_immv 6
 
 #define Anum_pg_ivm_immv_immvrelid 1
 #define Anum_pg_ivm_immv_viewdef 2
 #define Anum_pg_ivm_immv_ispopulated 3
 #define Anum_pg_ivm_immv_lastivmupdate 4
 #define Anum_pg_ivm_immv_querystring 5
+#define Anum_pg_ivm_immv_immvuuid 6
+
+typedef struct ImmvAddress
+{
+	ObjectAddress	address;
+	pg_uuid_t		immv_uuid;
+} ImmvAddress;
 
 /* pg_ivm.c */
 
 extern void CreateChangePreventTrigger(Oid matviewOid);
 extern Oid PgIvmImmvRelationId(void);
 extern Oid PgIvmImmvPrimaryKeyIndexId(void);
+extern Oid PgIvmImmvUuidIndexId(void);
 extern bool isImmv(Oid immv_oid);
 extern List *PgIvmFuncName(char *name);
 extern void parse_immv_query(const char *relname, const char *sql,
 							 Query **query_ret, ParseState **pstate_ret);
+extern Oid GetImmvRelid(pg_uuid_t *immv_uuid);
+extern pg_uuid_t *GetImmvUuid(Oid immvrelid);
 
 /* createas.c */
 
 extern ObjectAddress ExecCreateImmv(ParseState *pstate, CreateTableAsStmt *stmt,
 									QueryCompletion *qc);
-extern void CreateIvmTriggersOnBaseTables(Query *qry, Oid matviewOid);
+extern void CreateIvmTriggersOnBaseTables(Query *qry, ImmvAddress immv_addr);
 extern void CreateIndexOnIMMV(Query *query, Relation matviewRel);
 extern Query *rewriteQueryForIMMV(Query *query, List *colNames);
 extern void makeIvmAggColumn(ParseState *pstate, Aggref *aggref, char *resname, AttrNumber *next_resno, List **aggs);
@@ -52,7 +63,7 @@ extern void makeIvmAggColumn(ParseState *pstate, Aggref *aggref, char *resname,
 extern Query *get_immv_query(Relation matviewRel);
 extern ObjectAddress ExecRefreshImmv(const RangeVar *relation, bool skipData,
 									 const char *queryString, QueryCompletion *qc);
-extern ObjectAddress RefreshImmvByOid(Oid matviewOid, bool is_create, bool skipData,
+extern ObjectAddress RefreshImmvByOid(ImmvAddress immv_addr, bool is_create, bool skipData,
 									  const char *queryString, QueryCompletion *qc);
 extern bool ImmvIncrementalMaintenanceIsEnabled(void);
 extern Datum IVM_immediate_before(PG_FUNCTION_ARGS);

From 0be0a58bc902b0733e04387824b0ee1d58fbf492 Mon Sep 17 00:00:00 2001
From: Adam Guo <adamguo@amazon.com>
Date: Tue, 20 May 2025 23:46:39 +0000
Subject: [PATCH 11/13] External triggers

---
 createas.c      | 8 +++++---
 event_trigger.c | 1 +
 matview.c       | 4 ++--
 pg_ivm.c        | 5 +++--
 4 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/createas.c b/createas.c
index 10a09c0..3385255 100644
--- a/createas.c
+++ b/createas.c
@@ -747,6 +747,8 @@ CreateIvmTrigger(Oid relOid, ImmvAddress immv_addr, int16 type, int16 timing, bo
 	if (type == TRIGGER_TYPE_DELETE || type == TRIGGER_TYPE_UPDATE)
 		ex_lock = true;
 
+	ivm_trigger->trigname = psprintf("%s_%d_%d", ivm_trigger->trigname, relOid,
+									 immv_addr.address.objectId);
 	ivm_trigger->funcname =
 		(timing == TRIGGER_TYPE_BEFORE ?
 			PgIvmFuncName("IVM_immediate_before") : PgIvmFuncName("IVM_immediate_maintenance"));
@@ -759,12 +761,12 @@ CreateIvmTrigger(Oid relOid, ImmvAddress immv_addr, int16 type, int16 timing, bo
 	ivm_trigger->initdeferred = false;
 	ivm_trigger->constrrel = NULL;
 	ivm_trigger->args = list_make2(
-		makeString(DatumGetPointer(UUIDPGetDatum(&immv_addr.immv_uuid))),
+		makeString(DatumGetPointer(DirectFunctionCall1(uuid_out, UUIDPGetDatum(&immv_addr.immv_uuid)))),
 		makeString(DatumGetPointer(DirectFunctionCall1(boolout, BoolGetDatum(ex_lock))))
 		);
 
 	address = CreateTrigger(ivm_trigger, NULL, relOid, InvalidOid, InvalidOid,
-						 InvalidOid, InvalidOid, InvalidOid, NULL, true, false);
+						 InvalidOid, InvalidOid, InvalidOid, NULL, false, false);
 
 	recordDependencyOn(&address, &refaddr, DEPENDENCY_AUTO);
 
@@ -1733,7 +1735,7 @@ StoreImmvQuery(ImmvAddress immv_addr, Query *viewQuery)
 	 */
 	save_nestlevel = NewGUCNestLevel();
 	RestrictSearchPath();
-	matviewRel = table_open(viewOid, AccessShareLock);
+	matviewRel = table_open(immv_addr.address.objectId, AccessShareLock);
 	querystring = pg_ivm_get_viewdef_internal(viewQuery, matviewRel, true);
 	table_close(matviewRel, NoLock);
 	/* Roll back the search_path change. */
diff --git a/event_trigger.c b/event_trigger.c
index d23b4ac..77685f8 100644
--- a/event_trigger.c
+++ b/event_trigger.c
@@ -1,6 +1,7 @@
 #include "postgres.h"
 #include "pg_ivm.h"
 
+#include "access/genam.h"
 #include "access/table.h"
 #include "catalog/indexing.h"
 #include "commands/event_trigger.h"
diff --git a/matview.c b/matview.c
index b42001c..cfce832 100644
--- a/matview.c
+++ b/matview.c
@@ -857,7 +857,7 @@ IVM_immediate_before(PG_FUNCTION_ARGS)
 	bool	found;
 	bool	ex_lock;
 
-	immv_uuid = DatumGetUUIDP(CStringGetDatum(immv_uuid_text));
+	immv_uuid = DatumGetUUIDP(DirectFunctionCall1(uuid_in, (CStringGetDatum(immv_uuid_text))));
 	ex_lock = DatumGetBool(DirectFunctionCall1(boolin, CStringGetDatum(ex_lock_text)));
 	matviewOid = GetImmvRelid(immv_uuid);
 
@@ -1006,7 +1006,7 @@ IVM_immediate_maintenance(PG_FUNCTION_ARGS)
 	rel = trigdata->tg_relation;
 	relid = rel->rd_id;
 
-	immv_uuid = DatumGetUUIDP(CStringGetDatum(immv_uuid_text));
+	immv_uuid = DatumGetUUIDP(DirectFunctionCall1(uuid_in, (CStringGetDatum(immv_uuid_text))));
 	matviewOid = GetImmvRelid(immv_uuid);
 
 	/*
diff --git a/pg_ivm.c b/pg_ivm.c
index 6b8e1d4..88c5841 100644
--- a/pg_ivm.c
+++ b/pg_ivm.c
@@ -320,7 +320,6 @@ CreateChangePreventTrigger(Oid matviewOid)
 	ivm_trigger->row = false;
 
 	ivm_trigger->timing = TRIGGER_TYPE_BEFORE;
-	ivm_trigger->trigname = "IVM_prevent_immv_change";
 	ivm_trigger->funcname = PgIvmFuncName("IVM_prevent_immv_change");
 	ivm_trigger->columns = NIL;
 	ivm_trigger->transitionRels = NIL;
@@ -334,8 +333,10 @@ CreateChangePreventTrigger(Oid matviewOid)
 	for (i = 0; i < 4; i++)
 	{
 		ivm_trigger->events = types[i];
+		ivm_trigger->trigname = psprintf("IVM_prevent_immv_change_%d_%d",
+										 matviewOid, i + 1);
 		address = CreateTrigger(ivm_trigger, NULL, matviewOid, InvalidOid, InvalidOid,
-							 InvalidOid, InvalidOid, InvalidOid, NULL, true, false);
+							 InvalidOid, InvalidOid, InvalidOid, NULL, false, false);
 
 		recordDependencyOn(&address, &refaddr, DEPENDENCY_AUTO);
 	}

From c13a33d847ddbae0febc8cdfa40d292247495e7f Mon Sep 17 00:00:00 2001
From: Adam Guo <adamguo@amazon.com>
Date: Wed, 21 May 2025 00:10:15 +0000
Subject: [PATCH 12/13] sql scripts

---
 pg_ivm--1.10--1.11.sql | 11 ++++--
 pg_ivm--1.11.sql       | 78 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 87 insertions(+), 2 deletions(-)
 create mode 100644 pg_ivm--1.11.sql

diff --git a/pg_ivm--1.10--1.11.sql b/pg_ivm--1.10--1.11.sql
index 1e718de..35aba6d 100644
--- a/pg_ivm--1.10--1.11.sql
+++ b/pg_ivm--1.10--1.11.sql
@@ -1,6 +1,13 @@
-ALTER TABLE pgivm.pg_ivm_immv ADD COLUMN querystring text NOT NULL;
-ALTER TABLE pgivm.pg_ivm_immv ADD COLUMN immvuuid uuid NOT NULL;
+ALTER TABLE pgivm.pg_ivm_immv ADD COLUMN querystring text;
+ALTER TABLE pgivm.pg_ivm_immv ADD COLUMN immvuuid uuid;
+
+UPDATE pgivm.pg_ivm_immv SET querystring = pgivm.get_immv_def(immvrelid);
+UPDATE pgivm.pg_ivm_immv SET immvuuid = gen_random_uuid();
+
 ALTER TABLE pgivm.pg_ivm_immv ADD CONSTRAINT pg_ivm_immv_uuid UNIQUE (immvuuid);
+ALTER TABLE pgivm.pg_ivm_immv ALTER COLUMN querystring SET NOT NULL;
+ALTER TABLE pgivm.pg_ivm_immv ALTER COLUMN immvuuid SET NOT NULL;
+ALTER TABLE pgivm.pg_ivm_immv DROP COLUMN viewdef;
 
 CREATE FUNCTION pgivm.recreate_all_immvs() RETURNS VOID LANGUAGE PLPGSQL AS
 $$
diff --git a/pg_ivm--1.11.sql b/pg_ivm--1.11.sql
new file mode 100644
index 0000000..8181acc
--- /dev/null
+++ b/pg_ivm--1.11.sql
@@ -0,0 +1,78 @@
+CREATE SCHEMA pgivm;
+
+-- catalog
+
+CREATE TABLE pgivm.pg_ivm_immv(
+  immvrelid regclass NOT NULL,
+  immvuuid uuid NOT NULL,
+  querystring text NOT NULL,
+  ispopulated bool NOT NULL,
+  lastivmupdate xid8,
+
+  CONSTRAINT pg_ivm_immv_pkey PRIMARY KEY (immvrelid),
+  CONSTRAINT pg_ivm_immv_uuid UNIQUE (immvuuid)
+);
+
+SELECT pg_catalog.pg_extension_config_dump('pgivm.pg_ivm_immv', '');
+
+-- functions
+
+CREATE FUNCTION pgivm.create_immv(text, text)
+RETURNS bigint 
+STRICT
+AS 'MODULE_PATHNAME', 'create_immv'
+LANGUAGE C;
+
+CREATE FUNCTION pgivm.refresh_immv(text, bool)
+RETURNS bigint
+STRICT
+AS 'MODULE_PATHNAME', 'refresh_immv'
+LANGUAGE C;
+
+CREATE FUNCTION pgivm.get_immv_def(IN immvrelid regclass)
+RETURNS text
+STRICT
+AS 'MODULE_PATHNAME', 'get_immv_def'
+LANGUAGE C;
+
+CREATE FUNCTION pgivm.ivm_visible_in_prestate(oid, tid, oid)
+RETURNS bool
+STABLE
+AS 'MODULE_PATHNAME', 'ivm_visible_in_prestate'
+LANGUAGE C;
+
+-- trigger functions
+
+CREATE FUNCTION pgivm."IVM_immediate_before"()
+RETURNS trigger 
+AS 'MODULE_PATHNAME', 'IVM_immediate_before'
+LANGUAGE C;
+
+CREATE FUNCTION pgivm."IVM_immediate_maintenance"()
+RETURNS trigger 
+AS 'MODULE_PATHNAME', 'IVM_immediate_maintenance'
+LANGUAGE C;
+
+CREATE FUNCTION pgivm."IVM_prevent_immv_change"()
+RETURNS trigger 
+AS 'MODULE_PATHNAME', 'IVM_prevent_immv_change'
+LANGUAGE C;
+
+GRANT SELECT ON TABLE pgivm.pg_ivm_immv TO PUBLIC;
+GRANT USAGE ON SCHEMA pgivm TO PUBLIC;
+
+-- event triggers
+
+CREATE FUNCTION pgivm.save_query_strings() RETURNS event_trigger
+AS 'MODULE_PATHNAME', 'save_query_strings' LANGUAGE C;
+
+CREATE FUNCTION pgivm.restore_query_strings() RETURNS event_trigger
+AS 'MODULE_PATHNAME', 'restore_query_strings' LANGUAGE C;
+
+CREATE EVENT TRIGGER save_query_strings
+ON ddl_command_start
+EXECUTE FUNCTION pgivm.save_query_strings();
+
+CREATE EVENT TRIGGER restore_query_strings
+ON ddl_command_end
+EXECUTE FUNCTION pgivm.restore_query_strings();

From f219050b3362dc02470811a872ed695778e067ec Mon Sep 17 00:00:00 2001
From: Adam Guo <adamguo@amazon.com>
Date: Wed, 21 May 2025 01:34:52 +0000
Subject: [PATCH 13/13] Clean up

---
 Makefile               |  2 +-
 createas.c             | 12 +++---
 event_trigger.c        | 42 +++++++++++++++++-
 matview.c              | 97 +++---------------------------------------
 pg_ivm--1.10--1.11.sql | 43 -------------------
 pg_ivm.h               | 16 ++++---
 6 files changed, 64 insertions(+), 148 deletions(-)
 delete mode 100644 pg_ivm--1.10--1.11.sql

diff --git a/Makefile b/Makefile
index 8ff11d3..47aba28 100644
--- a/Makefile
+++ b/Makefile
@@ -19,7 +19,7 @@ DATA = pg_ivm--1.0.sql \
        pg_ivm--1.3--1.4.sql pg_ivm--1.4--1.5.sql pg_ivm--1.5--1.6.sql \
        pg_ivm--1.6--1.7.sql pg_ivm--1.7--1.8.sql pg_ivm--1.8--1.9.sql \
        pg_ivm--1.9--1.10.sql \
-	   pg_ivm--1.10.sql pg_ivm--1.10--1.11.sql
+	   pg_ivm--1.10.sql pg_ivm--1.11.sql
 
 REGRESS = pg_ivm create_immv refresh_immv
 
diff --git a/createas.c b/createas.c
index 3385255..6526369 100644
--- a/createas.c
+++ b/createas.c
@@ -130,8 +130,10 @@ create_immv_internal(List *attrList, IntoClause *into)
 	 * so we don't need more code to complain if "replace" is false.)
 	 */
 	immv_addr.address = DefineRelation(create, relkind, InvalidOid, NULL, NULL);
-	/* Generate the IMMV UUID. */
-	// TODO: check for hash collision
+	/*
+	 * Generate the IMMV UUID.
+	 * TODO: check for hash collision
+	 */
 	immv_uuid = DatumGetUUIDP(DirectFunctionCall1(gen_random_uuid, (Datum) NULL));
 	memcpy(&immv_addr.immv_uuid, immv_uuid, sizeof(*immv_uuid));
 	pfree(immv_uuid);
@@ -1718,7 +1720,6 @@ get_primary_key_attnos_from_query(Query *query, List **constraintList)
 static void
 StoreImmvQuery(ImmvAddress immv_addr, Query *viewQuery)
 {
-	char   *querytree = nodeToString((Node *) viewQuery);
 	char   *querystring;
 	int		save_nestlevel;
 	Datum values[Natts_pg_ivm_immv];
@@ -1745,10 +1746,9 @@ StoreImmvQuery(ImmvAddress immv_addr, Query *viewQuery)
 	memset(isNulls, false, sizeof(isNulls));
 
 	values[Anum_pg_ivm_immv_immvrelid -1 ] = ObjectIdGetDatum(immv_addr.address.objectId);
-	values[Anum_pg_ivm_immv_ispopulated -1 ] = BoolGetDatum(false);
-	values[Anum_pg_ivm_immv_viewdef -1 ] = CStringGetTextDatum(querytree);
-	values[Anum_pg_ivm_immv_querystring - 1] = CStringGetTextDatum(querystring);
 	values[Anum_pg_ivm_immv_immvuuid -1 ] = UUIDPGetDatum(&immv_addr.immv_uuid);
+	values[Anum_pg_ivm_immv_querystring - 1] = CStringGetTextDatum(querystring);
+	values[Anum_pg_ivm_immv_ispopulated -1 ] = BoolGetDatum(false);
 
 	pgIvmImmv = table_open(PgIvmImmvRelationId(), RowExclusiveLock);
 
diff --git a/event_trigger.c b/event_trigger.c
index 77685f8..c20e92e 100644
--- a/event_trigger.c
+++ b/event_trigger.c
@@ -14,6 +14,22 @@
 
 #define IMMV_INIT_QUERYHASHSIZE 16
 
+/*
+ * This file defines the DDL event triggers that maintain pgivm.pg_ivm_immv.
+ *
+ * Every time an ALTER RENAME statement is executed, the save_query_strings
+ * pre-event trigger will parse each IMMV's query string and store the Query
+ * nodes in a hash table.  Then, the restore_query_strings post-event trigger
+ * will take each Query node and re-create the query string.
+ *
+ * This allows the querystring column to remain up to date when any objects are
+ * renamed.
+ *
+ * TODO: This uses a brute force approach to checking if re-parse is necessary.
+ * Even if an unrelated object is renamed, these event triggers still fire.  Can
+ * figure out a more precise heuristic.
+ */
+
 typedef struct HashEntry
 {
 	Oid			immv_relid;
@@ -35,6 +51,9 @@ static void save_query_strings_internal(void);
 PG_FUNCTION_INFO_V1(save_query_strings);
 PG_FUNCTION_INFO_V1(restore_query_strings);
 
+/*
+ * Pre-DDL event trigger function.
+ */
 Datum
 save_query_strings(PG_FUNCTION_ARGS)
 {
@@ -55,6 +74,9 @@ save_query_strings(PG_FUNCTION_ARGS)
 	PG_RETURN_NULL();
 }
 
+/*
+ * Post-DDL event trigger function.
+ */
 Datum
 restore_query_strings(PG_FUNCTION_ARGS)
 {
@@ -73,6 +95,9 @@ restore_query_strings(PG_FUNCTION_ARGS)
 	PG_RETURN_NULL();
 }
 
+/*
+ * Initialize the hash table.
+ */
 static void
 initialize_query_cache(void)
 {
@@ -85,6 +110,9 @@ initialize_query_cache(void)
 								   &ctl, HASH_ELEM | HASH_BLOBS);
 }
 
+/*
+ * Store a query node in the hash table.
+ */
 static void
 hash_query(Oid immv_relid, char *query)
 {
@@ -103,6 +131,9 @@ hash_query(Oid immv_relid, char *query)
 	MemoryContextSwitchTo(old_cxt);
 }
 
+/*
+ * Retrieve a query node from the hash table.
+ */
 static char *
 retrieve_query(Oid immv_relid)
 {
@@ -125,6 +156,10 @@ retrieve_query(Oid immv_relid)
 	return query;
 }
 
+/*
+ * Iterate through the pg_ivm_immv table and parse the querystring of each
+ * entry.  Store the query nodes in the hash table.
+ */
 static void
 save_query_strings_internal(void)
 {
@@ -162,6 +197,7 @@ save_query_strings_internal(void)
 
 		/* Parse the existing IMMV query pre-DDL.  Add it to the list. */
 		parse_immv_query(matview_relname, query_string, &query, &parse_state);
+		query = (Query *) ((CreateTableAsStmt *) query->utilityStmt)->into->viewQuery;
 
 		/* Store entry for this IMMV. */
 		hash_query(matview_oid, nodeToString(query));
@@ -171,6 +207,11 @@ save_query_strings_internal(void)
 	table_close(pg_ivm_immv_rel, NoLock);
 }
 
+/*
+ * Iterate through the pg_ivm_immv table.  For each entry, get its Query node
+ * from the hash table and reconstruct the query string.  Update the row entry
+ * with the reconstructed query string.
+ */
 static void
 restore_query_strings_internal(void)
 {
@@ -211,7 +252,6 @@ restore_query_strings_internal(void)
 
 		serialized_query = retrieve_query(matview_oid);
 		query = stringToNode(serialized_query);
-		query = (Query *) ((CreateTableAsStmt *) query->utilityStmt)->into->viewQuery;
 
 		matview_rel = table_open(matview_oid, AccessShareLock);
 		new_query_string = pg_ivm_get_viewdef_internal(query, matview_rel, true);
diff --git a/matview.c b/matview.c
index cfce832..8b591e6 100644
--- a/matview.c
+++ b/matview.c
@@ -234,8 +234,6 @@ static void clean_up_IVM_hash_entry(MV_TriggerHashEntry *entry, bool is_abort,
 static void setLastUpdateXid(Oid immv_oid, FullTransactionId xid);
 static FullTransactionId getLastUpdateXid(Oid immv_oid);
 
-static Query *update_immv_viewdef(Relation matviewRel);
-
 /* SQL callable functions */
 PG_FUNCTION_INFO_V1(IVM_immediate_before);
 PG_FUNCTION_INFO_V1(IVM_immediate_maintenance);
@@ -397,18 +395,7 @@ RefreshImmvByOid(ImmvAddress immv_addr, bool is_create, bool skipData,
 	systable_endscan(scan);
 	table_close(pgIvmImmv, NoLock);
 
-	/*
-	 * Recreate the Query tree from the query string to account for changing
-	 * base table OIDs (e.g. after dump/restore) or changing format of the Query
-	 * node (after pg_upgrade).
-	 *
-	 * No need to create the Query tree a second time if we are creating a new
-	 * IMMV.
-	 */
-	if (is_create)
-		viewQuery = get_immv_query(matviewRel);
-	else
-		viewQuery = update_immv_viewdef(matviewRel);
+	viewQuery = get_immv_query(matviewRel);
 
 	/* For IMMV, we need to rewrite matview query */
 	if (!skipData)
@@ -707,6 +694,9 @@ get_immv_query(Relation matviewRel)
 	bool isnull;
 	Datum datum;
 	Query *query;
+	char *querystring;
+	char *relname;
+	ParseState *parse_state;
 
 	ScanKeyInit(&key,
 			    Anum_pg_ivm_immv_immvrelid,
@@ -724,91 +714,16 @@ get_immv_query(Relation matviewRel)
 		return NULL;
 	}
 
-	datum = heap_getattr(tup, Anum_pg_ivm_immv_viewdef, tupdesc, &isnull);
-	Assert(!isnull);
-	query = (Query *) stringToNode(TextDatumGetCString(datum));
-
-	systable_endscan(scan);
-	table_close(pgIvmImmv, NoLock);
-
-	return query;
-}
-
-/*
- * update_immv_viewdef
- *
- * Read the query string for this IMMV from pg_ivm_immv.  Parse the query string
- * and update the viewdef column with the new Query tree.  Return the Query
- * tree.
- */
-static Query *
-update_immv_viewdef(Relation matviewRel)
-{
-	CreateTableAsStmt *stmt;
-	Datum datum;
-	Datum values[Natts_pg_ivm_immv];
-	HeapTuple newtup = NULL;
-	HeapTuple tup;
-	IntoClause *into;
-	ParseState *pstate = NULL;
-	Query *query = NULL;
-	Relation pgIvmImmv = table_open(PgIvmImmvRelationId(), AccessShareLock);
-	ScanKeyData key;
-	SysScanDesc scan;
-	TupleDesc tupdesc = RelationGetDescr(pgIvmImmv);
-
-	bool isnull;
-	bool nulls[Natts_pg_ivm_immv];
-	bool replaces[Natts_pg_ivm_immv];
-	const char *querystring;
-	const char *querytree;
-	const char *relname;
-
-	/* Scan pg_ivm_immv for the given IMMV entry. */
-	ScanKeyInit(&key,
-			    Anum_pg_ivm_immv_immvrelid,
-				BTEqualStrategyNumber, F_OIDEQ,
-				ObjectIdGetDatum(RelationGetRelid(matviewRel)));
-	scan = systable_beginscan(pgIvmImmv, PgIvmImmvPrimaryKeyIndexId(),
-								  true, NULL, 1, &key);
-
-	tup = systable_getnext(scan);
-
-	if (!HeapTupleIsValid(tup))
-	{
-		systable_endscan(scan);
-		table_close(pgIvmImmv, NoLock);
-		return NULL;
-	}
-
-	/* Read the query string column. */
 	datum = heap_getattr(tup, Anum_pg_ivm_immv_querystring, tupdesc, &isnull);
 	Assert(!isnull);
 	querystring = TextDatumGetCString(datum);
 
-	/* Parse the query string using the same logic as create_immv. */
 	relname = psprintf("%s.%s",
 					   get_namespace_name(get_rel_namespace(matviewRel->rd_id)),
 					   get_rel_name(matviewRel->rd_id));
 
-	parse_immv_query(relname, querystring, &query, &pstate);
-	stmt = castNode(CreateTableAsStmt, query->utilityStmt);
-	into = stmt->into;
-
-	query = castNode(Query, stmt->query);
-	query = rewriteQueryForIMMV(query, into->colNames);
-	querytree = nodeToString((Node *) query);
-
-	/* Update the pg_ivm_immv tuple with the new query tree. */
-	memset(values, 0, sizeof(values));
-	memset(nulls, 0, sizeof(nulls));
-	memset(replaces, 0, sizeof(replaces));
-	values[Anum_pg_ivm_immv_viewdef - 1] = CStringGetTextDatum(querytree);
-	replaces[Anum_pg_ivm_immv_viewdef - 1] = true;
-
-	newtup = heap_modify_tuple(tup, tupdesc, values, nulls, replaces);
-	CatalogTupleUpdate(pgIvmImmv, &newtup->t_self, newtup);
-	heap_freetuple(newtup);
+	parse_immv_query(relname, querystring, &query, &parse_state);
+	query = (Query *) ((CreateTableAsStmt *) query->utilityStmt)->into->viewQuery;
 
 	systable_endscan(scan);
 	table_close(pgIvmImmv, NoLock);
diff --git a/pg_ivm--1.10--1.11.sql b/pg_ivm--1.10--1.11.sql
deleted file mode 100644
index 35aba6d..0000000
--- a/pg_ivm--1.10--1.11.sql
+++ /dev/null
@@ -1,43 +0,0 @@
-ALTER TABLE pgivm.pg_ivm_immv ADD COLUMN querystring text;
-ALTER TABLE pgivm.pg_ivm_immv ADD COLUMN immvuuid uuid;
-
-UPDATE pgivm.pg_ivm_immv SET querystring = pgivm.get_immv_def(immvrelid);
-UPDATE pgivm.pg_ivm_immv SET immvuuid = gen_random_uuid();
-
-ALTER TABLE pgivm.pg_ivm_immv ADD CONSTRAINT pg_ivm_immv_uuid UNIQUE (immvuuid);
-ALTER TABLE pgivm.pg_ivm_immv ALTER COLUMN querystring SET NOT NULL;
-ALTER TABLE pgivm.pg_ivm_immv ALTER COLUMN immvuuid SET NOT NULL;
-ALTER TABLE pgivm.pg_ivm_immv DROP COLUMN viewdef;
-
-CREATE FUNCTION pgivm.recreate_all_immvs() RETURNS VOID LANGUAGE PLPGSQL AS
-$$
-BEGIN
-	PERFORM pgivm.refresh_immv(n.nspname || '.' || c.relname, false)
-		FROM pgivm.pg_ivm_immv as ivm
-		JOIN pg_catalog.pg_class as c
-		ON c.oid = ivm.immvrelid
-		JOIN pg_catalog.pg_namespace as n
-		ON c.relnamespace = n.oid;
-
-	PERFORM pgivm.refresh_immv(n.nspname || '.' || c.relname, true)
-		FROM pgivm.pg_ivm_immv as ivm
-		JOIN pg_catalog.pg_class as c
-		ON c.oid = ivm.immvrelid
-		JOIN pg_catalog.pg_namespace as n
-		ON c.relnamespace = n.oid;
-END
-$$;
-
-CREATE FUNCTION pgivm.save_query_strings() RETURNS event_trigger
-AS 'MODULE_PATHNAME', 'save_query_strings' LANGUAGE C;
-
-CREATE FUNCTION pgivm.restore_query_strings() RETURNS event_trigger
-AS 'MODULE_PATHNAME', 'restore_query_strings' LANGUAGE C;
-
-CREATE EVENT TRIGGER save_query_strings
-ON ddl_command_start
-EXECUTE FUNCTION pgivm.save_query_strings();
-
-CREATE EVENT TRIGGER restore_query_strings
-ON ddl_command_end
-EXECUTE FUNCTION pgivm.restore_query_strings();
diff --git a/pg_ivm.h b/pg_ivm.h
index d8f80f9..b03d92f 100644
--- a/pg_ivm.h
+++ b/pg_ivm.h
@@ -21,15 +21,19 @@
 #include "utils/queryenvironment.h"
 #include "utils/uuid.h"
 
-#define Natts_pg_ivm_immv 6
+#define Natts_pg_ivm_immv 5
 
 #define Anum_pg_ivm_immv_immvrelid 1
-#define Anum_pg_ivm_immv_viewdef 2
-#define Anum_pg_ivm_immv_ispopulated 3
-#define Anum_pg_ivm_immv_lastivmupdate 4
-#define Anum_pg_ivm_immv_querystring 5
-#define Anum_pg_ivm_immv_immvuuid 6
+#define Anum_pg_ivm_immv_immvuuid 2
+#define Anum_pg_ivm_immv_querystring 3
+#define Anum_pg_ivm_immv_ispopulated 4
+#define Anum_pg_ivm_immv_lastivmupdate 5
 
+/*
+ * This struct uniquely identifies in IMMV.  It consists of an ObjectAddress
+ * (OID of the IMMV table and its schema) as well as a pg_uuid_t (which is
+ * stored in the pg_ivm_immv table).
+ */
 typedef struct ImmvAddress
 {
 	ObjectAddress	address;