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Posted to commits@cloudberry.apache.org by av...@apache.org on 2025/04/01 04:43:13 UTC
(cloudberry) 01/01: Optimize MV invalidation overhead using reference counting.
This is an automated email from the ASF dual-hosted git repository.
avamingli pushed a commit to branch mcrelcount
in repository https://gitbox.apache.org/repos/asf/cloudberry.git
commit 9107d6b94ddf882203a2b52426da980a9598ca68
Author: Zhang Mingli <av...@gmail.com>
AuthorDate: Tue Apr 1 12:42:30 2025 +0800
Optimize MV invalidation overhead using reference counting.
This commit optimizes the materialized view (MV) invalidation mechanism
to reduce overhead in OLTP workloads. The AQUMV feature introduced
`SetRelativeMatviewAuxStatus()` to invalidate MVs at appropriate times,
which GP7 lacks. However, TPC-B testing showed this function adds ~8.72%
OLTP overhead due to mandatory metadata operations, even when no MVs are
present.
To address this, we added `relmvrefcount` to track the number of MVs
dependent on a table. When no MVs reference a table, the system now
skips `SetRelativeMatviewAuxStatus()` entirely, avoiding unnecessary
catalog access. Benchmark results demonstrate significant improvements:
under 20 concurrent connections, transactions increased from 373,511 to
404,976, latency decreased from 16.06ms to 14.813ms, and TPS improved
from 1,245.3 to 1,350.2.
This optimization restores performance parity with GP7 in MV-free
scenarios while maintaining correctness for tables with MVs, delivering
measurable throughput gains and reduced latency in high-concurrency OLTP
workloads.
Authored-by: Zhang Mingli avamingli@gmail.com
---
src/backend/catalog/gp_matview_aux.c | 40 ++++++++++++++++++++++++++++++++++++
src/backend/catalog/heap.c | 1 +
src/backend/catalog/index.c | 1 +
src/backend/utils/cache/lsyscache.c | 24 ++++++++++++++++++++++
src/backend/utils/cache/relcache.c | 1 +
src/include/catalog/pg_class.h | 3 +++
src/include/utils/lsyscache.h | 1 +
src/include/utils/rel.h | 2 ++
8 files changed, 73 insertions(+)
diff --git a/src/backend/catalog/gp_matview_aux.c b/src/backend/catalog/gp_matview_aux.c
index fb728e666e..190a668883 100644
--- a/src/backend/catalog/gp_matview_aux.c
+++ b/src/backend/catalog/gp_matview_aux.c
@@ -58,6 +58,8 @@ static void RemoveMatviewTablesEntries(Oid mvoid);
static void SetMatviewAuxStatus_guts(Oid mvoid, char status);
+static void addRelationMVRefCount(Oid relid, int32 mvrefcount);
+
/*
* GetViewBaseRelids
* Get all base tables's oid of a query tree.
@@ -230,6 +232,9 @@ InsertMatviewTablesEntries(Oid mvoid, List *relids)
values[Anum_gp_matview_tables_mvoid - 1] = ObjectIdGetDatum(mvoid);
tup = heap_form_tuple(RelationGetDescr(mtRel), values, nulls);
CatalogTupleInsert(mtRel, tup);
+
+ /* update relation's pg_class entry */
+ addRelationMVRefCount(relid, 1);
}
table_close(mtRel, RowExclusiveLock);
@@ -278,6 +283,7 @@ RemoveMatviewTablesEntries(Oid mvoid)
Relation mtRel;
CatCList *catlist;
int i;
+ Oid relid;
mtRel = table_open(GpMatviewTablesId, RowExclusiveLock);
@@ -290,6 +296,10 @@ RemoveMatviewTablesEntries(Oid mvoid)
if (!HeapTupleIsValid(tuple))
continue;
+ /* update relation's pg_class entry */
+ relid = ((Form_gp_matview_tables) GETSTRUCT(tuple))->relid;
+ addRelationMVRefCount(relid, -1);
+
CatalogTupleDelete(mtRel, &tuple->t_self);
}
@@ -315,6 +325,12 @@ SetRelativeMatviewAuxStatus(Oid relid, char status, char direction)
List *base_oids;
ListCell *cell;
+ /*
+ * Do a quick check if relation has relative materialized views.
+ */
+ if (get_rel_relmvrefcount(relid) <= 0)
+ return;
+
mvauxRel = table_open(GpMatviewAuxId, RowExclusiveLock);
/* Find all mvoids have relid */
@@ -555,3 +571,27 @@ MatviewIsUpToDate(Oid mvoid)
Form_gp_matview_aux auxform = (Form_gp_matview_aux) GETSTRUCT(mvauxtup);
return (auxform->datastatus == MV_DATA_STATUS_UP_TO_DATE);
}
+
+static void
+addRelationMVRefCount(Oid relid, int32 mvrefcount)
+{
+ Relation pgrel;
+ HeapTuple tuple;
+
+ pgrel = table_open(RelationRelationId, RowExclusiveLock);
+ /*
+ * Update relation's pg_class entry.
+ */
+ tuple = SearchSysCacheCopy1(RELOID,
+ ObjectIdGetDatum(relid));
+ if (!HeapTupleIsValid(tuple))
+ elog(ERROR, "cache lookup failed for relation %u", relid);
+
+ ((Form_pg_class) GETSTRUCT(tuple))->relmvrefcount += mvrefcount;
+
+ CatalogTupleUpdate(pgrel, &tuple->t_self, tuple);
+
+ heap_freetuple(tuple);
+
+ table_close(pgrel, RowExclusiveLock);
+}
\ No newline at end of file
diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c
index 1e03200a73..7e9291e2bc 100644
--- a/src/backend/catalog/heap.c
+++ b/src/backend/catalog/heap.c
@@ -1328,6 +1328,7 @@ InsertPgClassTuple(Relation pg_class_desc,
values[Anum_pg_class_relminmxid - 1] = MultiXactIdGetDatum(rd_rel->relminmxid);
values[Anum_pg_class_relisivm - 1] = BoolGetDatum(rd_rel->relisivm);
values[Anum_pg_class_relisdynamic - 1] = BoolGetDatum(rd_rel->relisdynamic);
+ values[Anum_pg_class_relmvrefcount - 1] = Int32GetDatum(rd_rel->relmvrefcount);
if (relacl != (Datum) 0)
values[Anum_pg_class_relacl - 1] = relacl;
else
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 4349b1eb89..d754d97c78 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1074,6 +1074,7 @@ index_create_internal(Relation heapRelation,
indexRelation->rd_rel->relispartition = OidIsValid(parentIndexRelid);
indexRelation->rd_rel->relisivm = false;
indexRelation->rd_rel->relisdynamic = false;
+ indexRelation->rd_rel->relmvrefcount = 0;
/*
* store index's pg_class entry
diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c
index e2053385f2..25cefe8bc9 100644
--- a/src/backend/utils/cache/lsyscache.c
+++ b/src/backend/utils/cache/lsyscache.c
@@ -2142,6 +2142,30 @@ get_rel_relisdynamic(Oid relid)
return false;
}
+/*
+ * get_rel_relmvrefcount
+ *
+ * Returns the count of materialzed views associated with a given relation.
+ */
+int32
+get_rel_relmvrefcount(Oid relid)
+{
+ HeapTuple tp;
+
+ tp = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
+ if (HeapTupleIsValid(tp))
+ {
+ Form_pg_class reltup = (Form_pg_class) GETSTRUCT(tp);
+ int32 result;
+
+ result = reltup->relmvrefcount;
+ ReleaseSysCache(tp);
+ return result;
+ }
+ else
+ return 0;
+}
+
/*
* get_rel_tablespace
*
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 6f419e4428..a7ba7f5a4c 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -1987,6 +1987,7 @@ formrdesc(const char *relationName, Oid relationReltype,
relation->rd_rel->relisivm = false;
/* ... and they're always not dynamic, too */
relation->rd_rel->relisdynamic = false;
+ relation->rd_rel->relmvrefcount = 0;
relation->rd_rel->relreplident = REPLICA_IDENTITY_NOTHING;
relation->rd_rel->relpages = 0;
diff --git a/src/include/catalog/pg_class.h b/src/include/catalog/pg_class.h
index 6b29f0a73f..5d60f3fa33 100644
--- a/src/include/catalog/pg_class.h
+++ b/src/include/catalog/pg_class.h
@@ -125,6 +125,9 @@ CATALOG(pg_class,1259,RelationRelationId) BKI_BOOTSTRAP BKI_ROWTYPE_OID(83,Relat
/* is relation a dynamic table? */
bool relisdynamic BKI_DEFAULT(f);
+ /* count of materialized views referred to the relation */
+ int32 relmvrefcount BKI_DEFAULT(0);
+
/* link to original rel during table rewrite; otherwise 0 */
Oid relrewrite BKI_DEFAULT(0) BKI_LOOKUP_OPT(pg_class);
diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h
index 0822b1ae49..51224853ce 100644
--- a/src/include/utils/lsyscache.h
+++ b/src/include/utils/lsyscache.h
@@ -173,6 +173,7 @@ extern char get_rel_relkind(Oid relid);
extern bool get_rel_relispartition(Oid relid);
extern bool get_rel_relisivm(Oid relid);
extern bool get_rel_relisdynamic(Oid relid);
+extern int32 get_rel_relmvrefcount(Oid relid);
extern Oid get_rel_tablespace(Oid relid);
extern char get_rel_persistence(Oid relid);
extern Oid get_transform_fromsql(Oid typid, Oid langid, List *trftypes);
diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h
index 12b89808f7..d0b8c5cb47 100644
--- a/src/include/utils/rel.h
+++ b/src/include/utils/rel.h
@@ -783,6 +783,8 @@ typedef struct ViewOptions
#define RelationIsIVM(relation) ((relation)->rd_rel->relisivm)
+#define RelationHasRelativeMV(relation) (((relation)->rd_rel->relmvrefcount) > 0)
+
/*
* RelationIsAccessibleInLogicalDecoding
* True if we need to log enough information to have access via
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