Merge branch 'main' into fix_exists

README.md

@@ -80,7 +80,7 @@ When `pg_ivm` is installed, the following objects are created.
 
 ### Functions
 
-#### create_imm
+#### create_immv
 
 Use `create_immv` function to create IMMV.
 ```

expected/pg_ivm.out

@@ -828,6 +828,36 @@ SELECT * FROM mv_ivm_exists_subquery2 ORDER BY i, j;
  4 |  40 |                      1
 (4 rows)
 
+--- EXISTS subquery with tuple duplication and DISTINCT
+SELECT create_immv('mv_ivm_exists_subquery_distinct', 'SELECT DISTINCT a.i, a.j FROM mv_base_a a WHERE EXISTS(SELECT 1 FROM mv_base_b b WHERE a.i = b.i)');
+NOTICE:  created index "mv_ivm_exists_subquery_distinct_index" on immv "mv_ivm_exists_subquery_distinct"
+ create_immv 
+-------------
+           4
+(1 row)
+
+DELETE FROM mv_base_b WHERE i = 1 or i = 3;
+INSERT INTO mv_base_b VALUES (1,100), (3,300);
+SELECT * FROM mv_ivm_exists_subquery ORDER BY i, j;
+ i |  j  | __ivm_exists_count_0__ 
+---+-----+------------------------
+ 1 |  10 |                      1
+ 1 |  10 |                      1
+ 3 |  30 |                      1
+ 3 |  30 |                      1
+ 3 | 300 |                      1
+ 4 |  40 |                      1
+(6 rows)
+
+SELECT * FROM mv_ivm_exists_subquery_distinct ORDER BY i, j;
+ i |  j  | __ivm_exists_count_0__ | __ivm_count__ 
+---+-----+------------------------+---------------
+ 1 |  10 |                      1 |             2
+ 3 |  30 |                      1 |             2
+ 3 | 300 |                      1 |             1
+ 4 |  40 |                      1 |             1
+(4 rows)
+
 ROLLBACK;
 -- support simple subquery in FROM clause
 BEGIN;

matview.c

@@ -195,7 +195,7 @@ static void apply_new_delta(const char *matviewname, const char *deltaname_new,
 				StringInfo target_list);
 static void apply_new_delta_with_count(const char *matviewname, const char* deltaname_new,
 				List *keys, StringInfo target_list, StringInfo aggs_set,
-				const char* count_colname);
+				const char* count_colname, bool distinct);
 static char *get_matching_condition_string(List *keys);
 static char *get_returning_string(List *minmax_list, List *is_min_list, List *keys);
 static char *get_minmax_recalc_condition_string(List *minmax_list, List *is_min_list);
@@ -2024,7 +2024,8 @@ apply_delta(Oid matviewOid, Tuplestorestate *old_tuplestores, Tuplestorestate *n
 		/* apply new delta */
 		if (use_count)
 			apply_new_delta_with_count(matviewname, NEW_DELTA_ENRNAME,
-								keys, aggs_set_new, &target_list_buf, count_colname);
+								keys, aggs_set_new, &target_list_buf, count_colname,
+								query->distinctClause != NULL);
 		else
 			apply_new_delta(matviewname, NEW_DELTA_ENRNAME, &target_list_buf);
 	}
@@ -2508,12 +2509,14 @@ apply_old_delta(const char *matviewname, const char *deltaname_old,
 static void
 apply_new_delta_with_count(const char *matviewname, const char* deltaname_new,
 				List *keys, StringInfo aggs_set, StringInfo target_list,
-				const char* count_colname)
+				const char* count_colname, bool distinct)
 {
 	StringInfoData	querybuf;
 	StringInfoData	returning_keys;
 	ListCell	*lc;
 	char	*match_cond = "";
+	StringInfoData	deltaname_new_for_insert;
+
 
 	/* build WHERE condition for searching tuples to be updated */
 	match_cond = get_matching_condition_string(keys);
@@ -2534,6 +2537,24 @@ apply_new_delta_with_count(const char *matviewname, const char* deltaname_new,
 	else
 		appendStringInfo(&returning_keys, "NULL");
 
+	/*
+	 * If count_colname is not "__ivm_count__", the view contains EXISTS
+	 * subquery and the count column to be updated here is "__ivm_exists_count_*"
+	 * that stores the number of columns generated by corresponding EXISTS
+	 * subquery for each row in the view. In this case, __ivm_count__ in
+	 * deltaname_new stores duplicity of rows, and each row need to be
+	 * duplicated as much as __ivm_count__ by using generate_series at
+	 * inserting if DISTINCT is not used.
+	 */
+	initStringInfo(&deltaname_new_for_insert);
+	if (!strcmp(count_colname, "__ivm_count__") || distinct)
+		appendStringInfo(&deltaname_new_for_insert, "%s", deltaname_new);
+	else
+		appendStringInfo(&deltaname_new_for_insert,
+			"(SELECT diff.* FROM %s diff,"
+				"pg_catalog.generate_series(1, diff.\"__ivm_count__\"))",
+			deltaname_new);
+
 	/* Search for matching tuples from the view and update if found or insert if not. */
 	initStringInfo(&querybuf);
 	appendStringInfo(&querybuf,
@@ -2552,9 +2573,8 @@ apply_new_delta_with_count(const char *matviewname, const char* deltaname_new,
 					match_cond,
 					returning_keys.data,
 					matviewname, target_list->data,
-					target_list->data, deltaname_new,
+					target_list->data, deltaname_new_for_insert.data,
 					match_cond);
-
 	if (SPI_exec(querybuf.data, 0) != SPI_OK_INSERT)
 		elog(ERROR, "SPI_exec failed: %s", querybuf.data);
 }

pg_ivm.c

@@ -385,11 +385,25 @@ PgIvmObjectAccessHook(ObjectAccessType access, Oid classId,
 
 	if (access == OAT_DROP && classId == RelationRelationId && !OidIsValid(subId))
 	{
-		Relation pgIvmImmv = table_open(PgIvmImmvRelationId(), AccessShareLock);
+		Relation pgIvmImmv;
 		SysScanDesc scan;
 		ScanKeyData key;
 		HeapTuple tup;
+		Oid pgIvmImmvOid = PgIvmImmvRelationId();
+	
+		/* pg_ivm_immv is not created yet, so there are no IMMVs, either. */
+		if (pgIvmImmvOid == InvalidOid)
+			return;
 
+		/*
+		 * When the dropped table is pg_ivm_immv, we don't need to continue
+		 * any more. Also, in this case, the index on it is already dropped,
+		 * so the index scan below will fail and raise an error.
+		 */
+		if (objectId == pgIvmImmOid)
+			return;
+		
+		pgIvmImmv = table_open(pgIvmImmvOid, AccessShareLock);
 		ScanKeyInit(&key,
 					Anum_pg_ivm_immv_immvrelid,
 					BTEqualStrategyNumber, F_OIDEQ,

sql/pg_ivm.sql

@@ -269,6 +269,12 @@ DELETE FROM mv_base_a WHERE (i,j) = (1,60);
 DELETE FROM mv_base_b WHERE i = 2;
 SELECT * FROM mv_ivm_exists_subquery ORDER BY i, j;
 SELECT * FROM mv_ivm_exists_subquery2 ORDER BY i, j;
+--- EXISTS subquery with tuple duplication and DISTINCT
+SELECT create_immv('mv_ivm_exists_subquery_distinct', 'SELECT DISTINCT a.i, a.j FROM mv_base_a a WHERE EXISTS(SELECT 1 FROM mv_base_b b WHERE a.i = b.i)');
+DELETE FROM mv_base_b WHERE i = 1 or i = 3;
+INSERT INTO mv_base_b VALUES (1,100), (3,300);
+SELECT * FROM mv_ivm_exists_subquery ORDER BY i, j;
+SELECT * FROM mv_ivm_exists_subquery_distinct ORDER BY i, j;
 ROLLBACK;
 
 -- support simple subquery in FROM clause