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* [PATCH v18] Avoid orphaned objects dependencies
@ 2024-03-29 15:43 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2024-03-29 15:43 UTC (permalink / raw)
It's currently possible to create orphaned objects dependencies, for example:
Scenario 1:
session 1: begin; drop schema schem;
session 2: create a function in the schema schem
session 1: commit;
With the above, the function created in session 2 would be linked to a non
existing schema.
Scenario 2:
session 1: begin; create a function in the schema schem
session 2: drop schema schem;
session 1: commit;
With the above, the function created in session 1 would be linked to a non
existing schema.
To avoid those scenarios, a new lock (that conflicts with a lock taken by DROP)
has been put in place before the dependencies are being recorded. With this in
place, the drop schema in scenario 2 would be locked.
Also, after the new lock attempt, the patch checks that the object still exists:
with this in place session 2 in scenario 1 would be locked and would report an
error once session 1 committs (that would not be the case should session 1 abort
the transaction).
If the object is dropped before the new lock attempt is triggered then the patch
would also report an error (but with less details).
The patch takes into account any type of objects except the ones that are pinned
(they are not droppable because the system requires it).
A special case is done for objects that belong to the RelationRelationId class.
For those, we should be in one of the two following cases that would already
prevent the relation to be dropped:
1. The relation is already locked (could be an existing relation or a relation
that we are creating).
2. The relation is protected indirectly (i.e an index protected by a lock on
its table, a table protected by a lock on a function that depends the table...)
To avoid any risks for the RelationRelationId class case, we acquire a lock if
there is none. That may add unnecessary lock for 2. but that's worth it.
The patch adds a few tests for some dependency cases (that would currently produce
orphaned objects):
- schema and function (as the above scenarios)
- alter a dependency (function and schema)
- function and arg type
- function and return type
- function and function
- domain and domain
- table and type
- server and foreign data wrapper
---
src/backend/catalog/aclchk.c | 1 +
src/backend/catalog/dependency.c | 212 ++++++++++++++++++
src/backend/catalog/heap.c | 7 +
src/backend/catalog/index.c | 26 +++
src/backend/catalog/objectaddress.c | 57 +++++
src/backend/catalog/pg_aggregate.c | 9 +
src/backend/catalog/pg_attrdef.c | 1 +
src/backend/catalog/pg_cast.c | 5 +
src/backend/catalog/pg_collation.c | 1 +
src/backend/catalog/pg_constraint.c | 26 +++
src/backend/catalog/pg_conversion.c | 2 +
src/backend/catalog/pg_depend.c | 39 +++-
src/backend/catalog/pg_operator.c | 19 ++
src/backend/catalog/pg_proc.c | 17 +-
src/backend/catalog/pg_publication.c | 11 +
src/backend/catalog/pg_range.c | 6 +
src/backend/catalog/pg_type.c | 39 ++++
src/backend/catalog/toasting.c | 1 +
src/backend/commands/alter.c | 4 +
src/backend/commands/amcmds.c | 1 +
src/backend/commands/cluster.c | 7 +
src/backend/commands/event_trigger.c | 1 +
src/backend/commands/extension.c | 5 +
src/backend/commands/foreigncmds.c | 7 +
src/backend/commands/functioncmds.c | 6 +
src/backend/commands/indexcmds.c | 2 +
src/backend/commands/opclasscmds.c | 18 ++
src/backend/commands/operatorcmds.c | 30 +++
src/backend/commands/policy.c | 2 +
src/backend/commands/proclang.c | 3 +
src/backend/commands/sequence.c | 2 +
src/backend/commands/statscmds.c | 10 +
src/backend/commands/tablecmds.c | 24 +-
src/backend/commands/trigger.c | 29 ++-
src/backend/commands/tsearchcmds.c | 73 +++++-
src/backend/commands/typecmds.c | 84 +++++++
src/backend/rewrite/rewriteDefine.c | 1 +
src/backend/utils/errcodes.txt | 1 +
src/include/catalog/dependency.h | 3 +
src/include/catalog/objectaddress.h | 1 +
.../expected/test_dependencies_locks.out | 129 +++++++++++
src/test/isolation/isolation_schedule | 1 +
.../specs/test_dependencies_locks.spec | 89 ++++++++
.../test_oat_hooks/expected/alter_table.out | 4 +-
.../expected/test_oat_hooks.out | 2 +
src/test/regress/expected/alter_table.out | 11 +-
46 files changed, 1009 insertions(+), 20 deletions(-)
40.0% src/backend/catalog/
29.8% src/backend/commands/
16.8% src/test/isolation/expected/
10.5% src/test/isolation/specs/
diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c
index b196294fb2..126a648597 100644
--- a/src/backend/catalog/aclchk.c
+++ b/src/backend/catalog/aclchk.c
@@ -1341,6 +1341,7 @@ SetDefaultACL(InternalDefaultACL *iacls)
referenced.objectId = iacls->nspid;
referenced.objectSubId = 0;
+ LockNotPinnedObject(NamespaceRelationId, iacls->nspid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
}
}
diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index 096b68c7f3..5149e28aa0 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -1519,6 +1519,81 @@ AcquireDeletionLock(const ObjectAddress *object, int flags)
}
}
+/*
+ * LockNotPinnedObjectById
+ *
+ * Lock the object that we are about to record a dependency on.
+ * After it's locked, verify that it hasn't been dropped while we
+ * weren't looking. If the object has been dropped, this function
+ * does not return!
+ */
+void
+LockNotPinnedObjectById(const ObjectAddress *object)
+{
+ char *object_description = NULL;
+
+ if (isObjectPinned(object))
+ return;
+
+ object_description = getObjectDescription(object, true);
+
+ if (object->classId == RelationRelationId)
+ {
+ Assert(!IsSharedRelation(object->objectId));
+
+ /*
+ * We must be in one of the two following cases that would already
+ * prevent the relation to be dropped: 1. The relation is already
+ * locked (could be an existing relation or a relation that we are
+ * creating). 2. The relation is protected indirectly (i.e an index
+ * protected by a lock on its table, a table protected by a lock on a
+ * function that depends of the table...). To avoid any risks, acquire
+ * a lock if there is none. That may add unnecessary lock for 2. but
+ * that's worth it.
+ */
+ if (!CheckRelationOidLockedByMe(object->objectId, AccessShareLock, true))
+ LockRelationOid(object->objectId, AccessShareLock);
+ }
+ else
+ {
+ /* assume we should lock the whole object not a sub-object */
+ LockDatabaseObject(object->classId, object->objectId, 0, AccessShareLock);
+ }
+
+ /* check if object still exists */
+ if (!ObjectByIdExist(object))
+ {
+ if (object_description)
+ ereport(ERROR,
+ (errcode(ERRCODE_DEPENDENT_OBJECTS_DOES_NOT_EXIST),
+ errmsg("%s does not exist", object_description)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_DEPENDENT_OBJECTS_DOES_NOT_EXIST),
+ errmsg("a dependent object does not exist")));
+ }
+
+ if (object_description)
+ pfree(object_description);
+
+ return;
+}
+
+/*
+ * LockNotPinnedObject
+ *
+ * Lock the object that we are about to record a dependency on.
+ */
+void
+LockNotPinnedObject(Oid classid, Oid objid)
+{
+ ObjectAddress object;
+
+ ObjectAddressSet(object, classid, objid);
+
+ LockNotPinnedObjectById(&object);
+}
+
/*
* ReleaseDeletionLock - release an object deletion lock
*
@@ -1730,6 +1805,7 @@ find_expr_references_walker(Node *node,
if (rte->rtekind == RTE_RELATION)
{
/* If it's a plain relation, reference this column */
+ LockNotPinnedObject(RelationRelationId, rte->relid);
add_object_address(RelationRelationId, rte->relid, var->varattno,
context->addrs);
}
@@ -1756,6 +1832,7 @@ find_expr_references_walker(Node *node,
Oid objoid;
/* A constant must depend on the constant's datatype */
+ LockNotPinnedObject(TypeRelationId, con->consttype);
add_object_address(TypeRelationId, con->consttype, 0,
context->addrs);
@@ -1767,8 +1844,11 @@ find_expr_references_walker(Node *node,
*/
if (OidIsValid(con->constcollid) &&
con->constcollid != DEFAULT_COLLATION_OID)
+ {
+ LockNotPinnedObject(CollationRelationId, con->constcollid);
add_object_address(CollationRelationId, con->constcollid, 0,
context->addrs);
+ }
/*
* If it's a regclass or similar literal referring to an existing
@@ -1785,59 +1865,83 @@ find_expr_references_walker(Node *node,
objoid = DatumGetObjectId(con->constvalue);
if (SearchSysCacheExists1(PROCOID,
ObjectIdGetDatum(objoid)))
+ {
+ LockNotPinnedObject(ProcedureRelationId, objoid);
add_object_address(ProcedureRelationId, objoid, 0,
context->addrs);
+ }
break;
case REGOPEROID:
case REGOPERATOROID:
objoid = DatumGetObjectId(con->constvalue);
if (SearchSysCacheExists1(OPEROID,
ObjectIdGetDatum(objoid)))
+ {
+ LockNotPinnedObject(OperatorRelationId, objoid);
add_object_address(OperatorRelationId, objoid, 0,
context->addrs);
+ }
break;
case REGCLASSOID:
objoid = DatumGetObjectId(con->constvalue);
if (SearchSysCacheExists1(RELOID,
ObjectIdGetDatum(objoid)))
+ {
+ LockNotPinnedObject(RelationRelationId, objoid);
add_object_address(RelationRelationId, objoid, 0,
context->addrs);
+ }
break;
case REGTYPEOID:
objoid = DatumGetObjectId(con->constvalue);
if (SearchSysCacheExists1(TYPEOID,
ObjectIdGetDatum(objoid)))
+ {
+ LockNotPinnedObject(TypeRelationId, objoid);
add_object_address(TypeRelationId, objoid, 0,
context->addrs);
+ }
break;
case REGCOLLATIONOID:
objoid = DatumGetObjectId(con->constvalue);
if (SearchSysCacheExists1(COLLOID,
ObjectIdGetDatum(objoid)))
+ {
+ LockNotPinnedObject(CollationRelationId, objoid);
add_object_address(CollationRelationId, objoid, 0,
context->addrs);
+ }
break;
case REGCONFIGOID:
objoid = DatumGetObjectId(con->constvalue);
if (SearchSysCacheExists1(TSCONFIGOID,
ObjectIdGetDatum(objoid)))
+ {
+ LockNotPinnedObject(TSConfigRelationId, objoid);
add_object_address(TSConfigRelationId, objoid, 0,
context->addrs);
+ }
break;
case REGDICTIONARYOID:
objoid = DatumGetObjectId(con->constvalue);
if (SearchSysCacheExists1(TSDICTOID,
ObjectIdGetDatum(objoid)))
+ {
+ LockNotPinnedObject(TSDictionaryRelationId, objoid);
add_object_address(TSDictionaryRelationId, objoid, 0,
context->addrs);
+ }
break;
case REGNAMESPACEOID:
objoid = DatumGetObjectId(con->constvalue);
if (SearchSysCacheExists1(NAMESPACEOID,
ObjectIdGetDatum(objoid)))
+ {
+ LockNotPinnedObject(NamespaceRelationId, objoid);
add_object_address(NamespaceRelationId, objoid, 0,
context->addrs);
+ }
break;
/*
@@ -1859,18 +1963,23 @@ find_expr_references_walker(Node *node,
Param *param = (Param *) node;
/* A parameter must depend on the parameter's datatype */
+ LockNotPinnedObject(TypeRelationId, param->paramtype);
add_object_address(TypeRelationId, param->paramtype, 0,
context->addrs);
/* and its collation, just as for Consts */
if (OidIsValid(param->paramcollid) &&
param->paramcollid != DEFAULT_COLLATION_OID)
+ {
+ LockNotPinnedObject(CollationRelationId, param->paramcollid);
add_object_address(CollationRelationId, param->paramcollid, 0,
context->addrs);
+ }
}
else if (IsA(node, FuncExpr))
{
FuncExpr *funcexpr = (FuncExpr *) node;
+ LockNotPinnedObject(ProcedureRelationId, funcexpr->funcid);
add_object_address(ProcedureRelationId, funcexpr->funcid, 0,
context->addrs);
/* fall through to examine arguments */
@@ -1879,6 +1988,7 @@ find_expr_references_walker(Node *node,
{
OpExpr *opexpr = (OpExpr *) node;
+ LockNotPinnedObject(OperatorRelationId, opexpr->opno);
add_object_address(OperatorRelationId, opexpr->opno, 0,
context->addrs);
/* fall through to examine arguments */
@@ -1887,6 +1997,7 @@ find_expr_references_walker(Node *node,
{
DistinctExpr *distinctexpr = (DistinctExpr *) node;
+ LockNotPinnedObject(OperatorRelationId, distinctexpr->opno);
add_object_address(OperatorRelationId, distinctexpr->opno, 0,
context->addrs);
/* fall through to examine arguments */
@@ -1895,6 +2006,7 @@ find_expr_references_walker(Node *node,
{
NullIfExpr *nullifexpr = (NullIfExpr *) node;
+ LockNotPinnedObject(OperatorRelationId, nullifexpr->opno);
add_object_address(OperatorRelationId, nullifexpr->opno, 0,
context->addrs);
/* fall through to examine arguments */
@@ -1903,6 +2015,7 @@ find_expr_references_walker(Node *node,
{
ScalarArrayOpExpr *opexpr = (ScalarArrayOpExpr *) node;
+ LockNotPinnedObject(OperatorRelationId, opexpr->opno);
add_object_address(OperatorRelationId, opexpr->opno, 0,
context->addrs);
/* fall through to examine arguments */
@@ -1911,6 +2024,7 @@ find_expr_references_walker(Node *node,
{
Aggref *aggref = (Aggref *) node;
+ LockNotPinnedObject(ProcedureRelationId, aggref->aggfnoid);
add_object_address(ProcedureRelationId, aggref->aggfnoid, 0,
context->addrs);
/* fall through to examine arguments */
@@ -1919,6 +2033,7 @@ find_expr_references_walker(Node *node,
{
WindowFunc *wfunc = (WindowFunc *) node;
+ LockNotPinnedObject(ProcedureRelationId, wfunc->winfnoid);
add_object_address(ProcedureRelationId, wfunc->winfnoid, 0,
context->addrs);
/* fall through to examine arguments */
@@ -1935,8 +2050,11 @@ find_expr_references_walker(Node *node,
*/
if (sbsref->refrestype != sbsref->refcontainertype &&
sbsref->refrestype != sbsref->refelemtype)
+ {
+ LockNotPinnedObject(TypeRelationId, sbsref->refrestype);
add_object_address(TypeRelationId, sbsref->refrestype, 0,
context->addrs);
+ }
/* fall through to examine arguments */
}
else if (IsA(node, SubPlan))
@@ -1960,16 +2078,25 @@ find_expr_references_walker(Node *node,
* anywhere else in the expression.
*/
if (OidIsValid(reltype))
+ {
+ LockNotPinnedObject(RelationRelationId, reltype);
add_object_address(RelationRelationId, reltype, fselect->fieldnum,
context->addrs);
+ }
else
+ {
+ LockNotPinnedObject(TypeRelationId, fselect->resulttype);
add_object_address(TypeRelationId, fselect->resulttype, 0,
context->addrs);
+ }
/* the collation might not be referenced anywhere else, either */
if (OidIsValid(fselect->resultcollid) &&
fselect->resultcollid != DEFAULT_COLLATION_OID)
+ {
+ LockNotPinnedObject(CollationRelationId, fselect->resultcollid);
add_object_address(CollationRelationId, fselect->resultcollid, 0,
context->addrs);
+ }
}
else if (IsA(node, FieldStore))
{
@@ -1980,53 +2107,76 @@ find_expr_references_walker(Node *node,
if (OidIsValid(reltype))
{
ListCell *l;
+ bool locked = false;
foreach(l, fstore->fieldnums)
+ {
+ if (!locked)
+ {
+ LockNotPinnedObject(RelationRelationId, reltype);
+ locked = true;
+ }
add_object_address(RelationRelationId, reltype, lfirst_int(l),
context->addrs);
+ }
}
else
+ {
+ LockNotPinnedObject(TypeRelationId, fstore->resulttype);
add_object_address(TypeRelationId, fstore->resulttype, 0,
context->addrs);
+ }
}
else if (IsA(node, RelabelType))
{
RelabelType *relab = (RelabelType *) node;
/* since there is no function dependency, need to depend on type */
+ LockNotPinnedObject(TypeRelationId, relab->resulttype);
add_object_address(TypeRelationId, relab->resulttype, 0,
context->addrs);
/* the collation might not be referenced anywhere else, either */
if (OidIsValid(relab->resultcollid) &&
relab->resultcollid != DEFAULT_COLLATION_OID)
+ {
+ LockNotPinnedObject(CollationRelationId, relab->resultcollid);
add_object_address(CollationRelationId, relab->resultcollid, 0,
context->addrs);
+ }
}
else if (IsA(node, CoerceViaIO))
{
CoerceViaIO *iocoerce = (CoerceViaIO *) node;
/* since there is no exposed function, need to depend on type */
+ LockNotPinnedObject(TypeRelationId, iocoerce->resulttype);
add_object_address(TypeRelationId, iocoerce->resulttype, 0,
context->addrs);
/* the collation might not be referenced anywhere else, either */
if (OidIsValid(iocoerce->resultcollid) &&
iocoerce->resultcollid != DEFAULT_COLLATION_OID)
+ {
+ LockNotPinnedObject(CollationRelationId, iocoerce->resultcollid);
add_object_address(CollationRelationId, iocoerce->resultcollid, 0,
context->addrs);
+ }
}
else if (IsA(node, ArrayCoerceExpr))
{
ArrayCoerceExpr *acoerce = (ArrayCoerceExpr *) node;
/* as above, depend on type */
+ LockNotPinnedObject(TypeRelationId, acoerce->resulttype);
add_object_address(TypeRelationId, acoerce->resulttype, 0,
context->addrs);
/* the collation might not be referenced anywhere else, either */
if (OidIsValid(acoerce->resultcollid) &&
acoerce->resultcollid != DEFAULT_COLLATION_OID)
+ {
+ LockNotPinnedObject(CollationRelationId, acoerce->resultcollid);
add_object_address(CollationRelationId, acoerce->resultcollid, 0,
context->addrs);
+ }
/* fall through to examine arguments */
}
else if (IsA(node, ConvertRowtypeExpr))
@@ -2034,6 +2184,7 @@ find_expr_references_walker(Node *node,
ConvertRowtypeExpr *cvt = (ConvertRowtypeExpr *) node;
/* since there is no function dependency, need to depend on type */
+ LockNotPinnedObject(TypeRelationId, cvt->resulttype);
add_object_address(TypeRelationId, cvt->resulttype, 0,
context->addrs);
}
@@ -2041,6 +2192,7 @@ find_expr_references_walker(Node *node,
{
CollateExpr *coll = (CollateExpr *) node;
+ LockNotPinnedObject(CollationRelationId, coll->collOid);
add_object_address(CollationRelationId, coll->collOid, 0,
context->addrs);
}
@@ -2048,6 +2200,7 @@ find_expr_references_walker(Node *node,
{
RowExpr *rowexpr = (RowExpr *) node;
+ LockNotPinnedObject(TypeRelationId, rowexpr->row_typeid);
add_object_address(TypeRelationId, rowexpr->row_typeid, 0,
context->addrs);
}
@@ -2058,11 +2211,13 @@ find_expr_references_walker(Node *node,
foreach(l, rcexpr->opnos)
{
+ LockNotPinnedObject(OperatorRelationId, lfirst_oid(l));
add_object_address(OperatorRelationId, lfirst_oid(l), 0,
context->addrs);
}
foreach(l, rcexpr->opfamilies)
{
+ LockNotPinnedObject(OperatorFamilyRelationId, lfirst_oid(l));
add_object_address(OperatorFamilyRelationId, lfirst_oid(l), 0,
context->addrs);
}
@@ -2072,6 +2227,7 @@ find_expr_references_walker(Node *node,
{
CoerceToDomain *cd = (CoerceToDomain *) node;
+ LockNotPinnedObject(TypeRelationId, cd->resulttype);
add_object_address(TypeRelationId, cd->resulttype, 0,
context->addrs);
}
@@ -2079,6 +2235,7 @@ find_expr_references_walker(Node *node,
{
NextValueExpr *nve = (NextValueExpr *) node;
+ LockNotPinnedObject(RelationRelationId, nve->seqid);
add_object_address(RelationRelationId, nve->seqid, 0,
context->addrs);
}
@@ -2087,19 +2244,26 @@ find_expr_references_walker(Node *node,
OnConflictExpr *onconflict = (OnConflictExpr *) node;
if (OidIsValid(onconflict->constraint))
+ {
+ LockNotPinnedObject(ConstraintRelationId, onconflict->constraint);
add_object_address(ConstraintRelationId, onconflict->constraint, 0,
context->addrs);
+ }
/* fall through to examine arguments */
}
else if (IsA(node, SortGroupClause))
{
SortGroupClause *sgc = (SortGroupClause *) node;
+ LockNotPinnedObject(OperatorRelationId, sgc->eqop);
add_object_address(OperatorRelationId, sgc->eqop, 0,
context->addrs);
if (OidIsValid(sgc->sortop))
+ {
+ LockNotPinnedObject(OperatorRelationId, sgc->sortop);
add_object_address(OperatorRelationId, sgc->sortop, 0,
context->addrs);
+ }
return false;
}
else if (IsA(node, WindowClause))
@@ -2107,15 +2271,24 @@ find_expr_references_walker(Node *node,
WindowClause *wc = (WindowClause *) node;
if (OidIsValid(wc->startInRangeFunc))
+ {
+ LockNotPinnedObject(ProcedureRelationId, wc->startInRangeFunc);
add_object_address(ProcedureRelationId, wc->startInRangeFunc, 0,
context->addrs);
+ }
if (OidIsValid(wc->endInRangeFunc))
+ {
+ LockNotPinnedObject(ProcedureRelationId, wc->endInRangeFunc);
add_object_address(ProcedureRelationId, wc->endInRangeFunc, 0,
context->addrs);
+ }
if (OidIsValid(wc->inRangeColl) &&
wc->inRangeColl != DEFAULT_COLLATION_OID)
+ {
+ LockNotPinnedObject(CollationRelationId, wc->inRangeColl);
add_object_address(CollationRelationId, wc->inRangeColl, 0,
context->addrs);
+ }
/* fall through to examine substructure */
}
else if (IsA(node, CTECycleClause))
@@ -2123,14 +2296,23 @@ find_expr_references_walker(Node *node,
CTECycleClause *cc = (CTECycleClause *) node;
if (OidIsValid(cc->cycle_mark_type))
+ {
+ LockNotPinnedObject(TypeRelationId, cc->cycle_mark_type);
add_object_address(TypeRelationId, cc->cycle_mark_type, 0,
context->addrs);
+ }
if (OidIsValid(cc->cycle_mark_collation))
+ {
+ LockNotPinnedObject(CollationRelationId, cc->cycle_mark_collation);
add_object_address(CollationRelationId, cc->cycle_mark_collation, 0,
context->addrs);
+ }
if (OidIsValid(cc->cycle_mark_neop))
+ {
+ LockNotPinnedObject(OperatorRelationId, cc->cycle_mark_neop);
add_object_address(OperatorRelationId, cc->cycle_mark_neop, 0,
context->addrs);
+ }
/* fall through to examine substructure */
}
else if (IsA(node, Query))
@@ -2163,6 +2345,7 @@ find_expr_references_walker(Node *node,
switch (rte->rtekind)
{
case RTE_RELATION:
+ LockNotPinnedObject(RelationRelationId, rte->relid);
add_object_address(RelationRelationId, rte->relid, 0,
context->addrs);
break;
@@ -2215,12 +2398,18 @@ find_expr_references_walker(Node *node,
rte = rt_fetch(query->resultRelation, query->rtable);
if (rte->rtekind == RTE_RELATION)
{
+ bool locked = false;
foreach(lc, query->targetList)
{
TargetEntry *tle = (TargetEntry *) lfirst(lc);
if (tle->resjunk)
continue; /* ignore junk tlist items */
+ if (!locked)
+ {
+ LockNotPinnedObject(RelationRelationId, rte->relid);
+ locked = true;
+ }
add_object_address(RelationRelationId, rte->relid, tle->resno,
context->addrs);
}
@@ -2232,6 +2421,7 @@ find_expr_references_walker(Node *node,
*/
foreach(lc, query->constraintDeps)
{
+ LockNotPinnedObject(ConstraintRelationId, lfirst_oid(lc));
add_object_address(ConstraintRelationId, lfirst_oid(lc), 0,
context->addrs);
}
@@ -2266,16 +2456,25 @@ find_expr_references_walker(Node *node,
*/
foreach(ct, rtfunc->funccoltypes)
{
+ LockNotPinnedObject(TypeRelationId, lfirst_oid(ct));
add_object_address(TypeRelationId, lfirst_oid(ct), 0,
context->addrs);
}
foreach(ct, rtfunc->funccolcollations)
{
Oid collid = lfirst_oid(ct);
+ bool locked = false;
if (OidIsValid(collid) && collid != DEFAULT_COLLATION_OID)
+ {
+ if (!locked)
+ {
+ LockNotPinnedObject(CollationRelationId, collid);
+ locked = true;
+ }
add_object_address(CollationRelationId, collid, 0,
context->addrs);
+ }
}
}
else if (IsA(node, TableFunc))
@@ -2288,22 +2487,32 @@ find_expr_references_walker(Node *node,
*/
foreach(ct, tf->coltypes)
{
+ LockNotPinnedObject(TypeRelationId, lfirst_oid(ct));
add_object_address(TypeRelationId, lfirst_oid(ct), 0,
context->addrs);
}
foreach(ct, tf->colcollations)
{
Oid collid = lfirst_oid(ct);
+ bool locked = false;
if (OidIsValid(collid) && collid != DEFAULT_COLLATION_OID)
+ {
+ if (!locked)
+ {
+ LockNotPinnedObject(CollationRelationId, collid);
+ locked = true;
+ }
add_object_address(CollationRelationId, collid, 0,
context->addrs);
+ }
}
}
else if (IsA(node, TableSampleClause))
{
TableSampleClause *tsc = (TableSampleClause *) node;
+ LockNotPinnedObject(ProcedureRelationId, tsc->tsmhandler);
add_object_address(ProcedureRelationId, tsc->tsmhandler, 0,
context->addrs);
/* fall through to examine arguments */
@@ -2354,9 +2563,12 @@ process_function_rte_ref(RangeTblEntry *rte, AttrNumber attnum,
Assert(attnum - atts_done <= tupdesc->natts);
if (OidIsValid(reltype)) /* can this fail? */
+ {
+ LockNotPinnedObject(RelationRelationId, reltype);
add_object_address(RelationRelationId, reltype,
attnum - atts_done,
context->addrs);
+ }
return;
}
/* Nothing to do; function's result type is handled elsewhere */
diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c
index 4d760c98d1..f333a91cfe 100644
--- a/src/backend/catalog/heap.c
+++ b/src/backend/catalog/heap.c
@@ -836,6 +836,7 @@ AddNewAttributeTuples(Oid new_rel_oid,
/* Add dependency info */
ObjectAddressSubSet(myself, RelationRelationId, new_rel_oid, i + 1);
ObjectAddressSet(referenced, TypeRelationId, attr->atttypid);
+ LockNotPinnedObject(TypeRelationId, attr->atttypid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
/* The default collation is pinned, so don't bother recording it */
@@ -844,6 +845,7 @@ AddNewAttributeTuples(Oid new_rel_oid,
{
ObjectAddressSet(referenced, CollationRelationId,
attr->attcollation);
+ LockNotPinnedObject(CollationRelationId, attr->attcollation);
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
}
}
@@ -1451,11 +1453,13 @@ heap_create_with_catalog(const char *relname,
ObjectAddressSet(referenced, NamespaceRelationId, relnamespace);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(NamespaceRelationId, relnamespace);
if (reloftypeid)
{
ObjectAddressSet(referenced, TypeRelationId, reloftypeid);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(TypeRelationId, reloftypeid);
}
/*
@@ -1471,6 +1475,7 @@ heap_create_with_catalog(const char *relname,
{
ObjectAddressSet(referenced, AccessMethodRelationId, accessmtd);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(AccessMethodRelationId, accessmtd);
}
record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
@@ -3771,6 +3776,7 @@ StorePartitionKey(Relation rel,
{
ObjectAddressSet(referenced, OperatorClassRelationId, partopclass[i]);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(OperatorClassRelationId, partopclass[i]);
/* The default collation is pinned, so don't bother recording it */
if (OidIsValid(partcollation[i]) &&
@@ -3778,6 +3784,7 @@ StorePartitionKey(Relation rel,
{
ObjectAddressSet(referenced, CollationRelationId, partcollation[i]);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(CollationRelationId, partcollation[i]);
}
}
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 221fbb4e28..1e5859ad4b 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1117,6 +1117,7 @@ index_create(Relation heapRelation,
else
{
bool have_simple_col = false;
+ bool locked_object = false;
addrs = new_object_addresses();
@@ -1129,6 +1130,12 @@ index_create(Relation heapRelation,
heapRelationId,
indexInfo->ii_IndexAttrNumbers[i]);
add_exact_object_address(&referenced, addrs);
+
+ if (!locked_object)
+ {
+ LockNotPinnedObject(RelationRelationId, heapRelationId);
+ locked_object = true;
+ }
have_simple_col = true;
}
}
@@ -1144,6 +1151,8 @@ index_create(Relation heapRelation,
ObjectAddressSet(referenced, RelationRelationId,
heapRelationId);
add_exact_object_address(&referenced, addrs);
+
+ LockNotPinnedObject(RelationRelationId, heapRelationId);
}
record_object_address_dependencies(&myself, addrs, DEPENDENCY_AUTO);
@@ -1159,9 +1168,13 @@ index_create(Relation heapRelation,
if (OidIsValid(parentIndexRelid))
{
ObjectAddressSet(referenced, RelationRelationId, parentIndexRelid);
+
+ LockNotPinnedObject(RelationRelationId, parentIndexRelid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_PARTITION_PRI);
ObjectAddressSet(referenced, RelationRelationId, heapRelationId);
+
+ LockNotPinnedObject(RelationRelationId, heapRelationId);
recordDependencyOn(&myself, &referenced, DEPENDENCY_PARTITION_SEC);
}
@@ -1177,6 +1190,7 @@ index_create(Relation heapRelation,
{
ObjectAddressSet(referenced, CollationRelationId, collationIds[i]);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(CollationRelationId, collationIds[i]);
}
}
@@ -1185,6 +1199,7 @@ index_create(Relation heapRelation,
{
ObjectAddressSet(referenced, OperatorClassRelationId, opclassIds[i]);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(OperatorClassRelationId, opclassIds[i]);
}
record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
@@ -1994,6 +2009,14 @@ index_constraint_create(Relation heapRelation,
*/
ObjectAddressSet(myself, ConstraintRelationId, conOid);
ObjectAddressSet(idxaddr, RelationRelationId, indexRelationId);
+
+ /*
+ * CommandCounterIncrement() here to ensure the new constraint entry is
+ * visible when LockNotPinnedObject() will check its existence before
+ * recording the dependencies.
+ */
+ CommandCounterIncrement();
+ LockNotPinnedObject(ConstraintRelationId, conOid);
recordDependencyOn(&idxaddr, &myself, DEPENDENCY_INTERNAL);
/*
@@ -2005,9 +2028,12 @@ index_constraint_create(Relation heapRelation,
ObjectAddress referenced;
ObjectAddressSet(referenced, ConstraintRelationId, parentConstraintId);
+ LockNotPinnedObject(ConstraintRelationId, parentConstraintId);
recordDependencyOn(&myself, &referenced, DEPENDENCY_PARTITION_PRI);
ObjectAddressSet(referenced, RelationRelationId,
RelationGetRelid(heapRelation));
+
+ LockNotPinnedObject(RelationRelationId, RelationGetRelid(heapRelation));
recordDependencyOn(&myself, &referenced, DEPENDENCY_PARTITION_SEC);
}
diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c
index d8eb8d3dea..f3e82671df 100644
--- a/src/backend/catalog/objectaddress.c
+++ b/src/backend/catalog/objectaddress.c
@@ -2595,6 +2595,63 @@ get_object_namespace(const ObjectAddress *address)
return oid;
}
+/*
+ * ObjectByIdExist
+ *
+ * Return whether the given object exists.
+ *
+ * Works for most catalogs, if no special processing is needed.
+ */
+bool
+ObjectByIdExist(const ObjectAddress *address)
+{
+ HeapTuple tuple;
+ int cache;
+ const ObjectPropertyType *property;
+
+ property = get_object_property_data(address->classId);
+
+ cache = property->oid_catcache_id;
+
+ if (cache >= 0)
+ {
+ /* Fetch tuple from syscache. */
+ tuple = SearchSysCache1(cache, ObjectIdGetDatum(address->objectId));
+
+ if (!HeapTupleIsValid(tuple))
+ {
+ return false;
+ }
+
+ ReleaseSysCache(tuple);
+
+ return true;
+ }
+ else
+ {
+ Relation rel;
+ ScanKeyData skey[1];
+ SysScanDesc scan;
+
+ rel = table_open(address->classId, AccessShareLock);
+
+ ScanKeyInit(&skey[0],
+ get_object_attnum_oid(address->classId),
+ BTEqualStrategyNumber, F_OIDEQ,
+ ObjectIdGetDatum(address->objectId));
+
+ scan = systable_beginscan(rel, get_object_oid_index(address->classId), true,
+ NULL, 1, skey);
+
+ /* we expect exactly one match */
+ tuple = systable_getnext(scan);
+ systable_endscan(scan);
+ table_close(rel, AccessShareLock);
+
+ return (HeapTupleIsValid(tuple));
+ }
+}
+
/*
* Return ObjectType for the given object type as given by
* getObjectTypeDescription; if no valid ObjectType code exists, but it's a
diff --git a/src/backend/catalog/pg_aggregate.c b/src/backend/catalog/pg_aggregate.c
index bcf4050f5b..ce5865fac6 100644
--- a/src/backend/catalog/pg_aggregate.c
+++ b/src/backend/catalog/pg_aggregate.c
@@ -748,12 +748,14 @@ AggregateCreate(const char *aggName,
/* Depends on transition function */
ObjectAddressSet(referenced, ProcedureRelationId, transfn);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(ProcedureRelationId, transfn);
/* Depends on final function, if any */
if (OidIsValid(finalfn))
{
ObjectAddressSet(referenced, ProcedureRelationId, finalfn);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(ProcedureRelationId, finalfn);
}
/* Depends on combine function, if any */
@@ -761,6 +763,7 @@ AggregateCreate(const char *aggName,
{
ObjectAddressSet(referenced, ProcedureRelationId, combinefn);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(ProcedureRelationId, combinefn);
}
/* Depends on serialization function, if any */
@@ -768,6 +771,7 @@ AggregateCreate(const char *aggName,
{
ObjectAddressSet(referenced, ProcedureRelationId, serialfn);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(ProcedureRelationId, serialfn);
}
/* Depends on deserialization function, if any */
@@ -775,6 +779,7 @@ AggregateCreate(const char *aggName,
{
ObjectAddressSet(referenced, ProcedureRelationId, deserialfn);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(ProcedureRelationId, deserialfn);
}
/* Depends on forward transition function, if any */
@@ -782,6 +787,7 @@ AggregateCreate(const char *aggName,
{
ObjectAddressSet(referenced, ProcedureRelationId, mtransfn);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(ProcedureRelationId, mtransfn);
}
/* Depends on inverse transition function, if any */
@@ -789,6 +795,7 @@ AggregateCreate(const char *aggName,
{
ObjectAddressSet(referenced, ProcedureRelationId, minvtransfn);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(ProcedureRelationId, minvtransfn);
}
/* Depends on final function, if any */
@@ -796,6 +803,7 @@ AggregateCreate(const char *aggName,
{
ObjectAddressSet(referenced, ProcedureRelationId, mfinalfn);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(ProcedureRelationId, mfinalfn);
}
/* Depends on sort operator, if any */
@@ -803,6 +811,7 @@ AggregateCreate(const char *aggName,
{
ObjectAddressSet(referenced, OperatorRelationId, sortop);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(OperatorRelationId, sortop);
}
record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
diff --git a/src/backend/catalog/pg_attrdef.c b/src/backend/catalog/pg_attrdef.c
index 91dafc8102..91da30c504 100644
--- a/src/backend/catalog/pg_attrdef.c
+++ b/src/backend/catalog/pg_attrdef.c
@@ -178,6 +178,7 @@ StoreAttrDefault(Relation rel, AttrNumber attnum,
colobject.objectId = RelationGetRelid(rel);
colobject.objectSubId = attnum;
+ LockNotPinnedObject(RelationRelationId, RelationGetRelid(rel));
recordDependencyOn(&defobject, &colobject,
attgenerated ? DEPENDENCY_INTERNAL : DEPENDENCY_AUTO);
diff --git a/src/backend/catalog/pg_cast.c b/src/backend/catalog/pg_cast.c
index 1773c9c549..90513a39ac 100644
--- a/src/backend/catalog/pg_cast.c
+++ b/src/backend/catalog/pg_cast.c
@@ -97,16 +97,19 @@ CastCreate(Oid sourcetypeid, Oid targettypeid,
/* dependency on source type */
ObjectAddressSet(referenced, TypeRelationId, sourcetypeid);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(TypeRelationId, sourcetypeid);
/* dependency on target type */
ObjectAddressSet(referenced, TypeRelationId, targettypeid);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(TypeRelationId, targettypeid);
/* dependency on function */
if (OidIsValid(funcid))
{
ObjectAddressSet(referenced, ProcedureRelationId, funcid);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(ProcedureRelationId, funcid);
}
/* dependencies on casts required for function */
@@ -114,11 +117,13 @@ CastCreate(Oid sourcetypeid, Oid targettypeid,
{
ObjectAddressSet(referenced, CastRelationId, incastid);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(CastRelationId, incastid);
}
if (OidIsValid(outcastid))
{
ObjectAddressSet(referenced, CastRelationId, outcastid);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(CastRelationId, outcastid);
}
record_object_address_dependencies(&myself, addrs, behavior);
diff --git a/src/backend/catalog/pg_collation.c b/src/backend/catalog/pg_collation.c
index 469635b358..fa6fd7bf79 100644
--- a/src/backend/catalog/pg_collation.c
+++ b/src/backend/catalog/pg_collation.c
@@ -218,6 +218,7 @@ CollationCreate(const char *collname, Oid collnamespace,
referenced.classId = NamespaceRelationId;
referenced.objectId = collnamespace;
referenced.objectSubId = 0;
+ LockNotPinnedObject(NamespaceRelationId, collnamespace);
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
/* create dependency on owner */
diff --git a/src/backend/catalog/pg_constraint.c b/src/backend/catalog/pg_constraint.c
index 0c6ac0be41..cee0bdc280 100644
--- a/src/backend/catalog/pg_constraint.c
+++ b/src/backend/catalog/pg_constraint.c
@@ -257,17 +257,26 @@ CreateConstraintEntry(const char *constraintName,
if (constraintNTotalKeys > 0)
{
+ bool locked_object = false;
+
for (i = 0; i < constraintNTotalKeys; i++)
{
ObjectAddressSubSet(relobject, RelationRelationId, relId,
constraintKey[i]);
add_exact_object_address(&relobject, addrs_auto);
+
+ if (!locked_object)
+ {
+ LockNotPinnedObject(RelationRelationId, relId);
+ locked_object = true;
+ }
}
}
else
{
ObjectAddressSet(relobject, RelationRelationId, relId);
add_exact_object_address(&relobject, addrs_auto);
+ LockNotPinnedObject(RelationRelationId, relId);
}
}
@@ -280,6 +289,7 @@ CreateConstraintEntry(const char *constraintName,
ObjectAddressSet(domobject, TypeRelationId, domainId);
add_exact_object_address(&domobject, addrs_auto);
+ LockNotPinnedObject(TypeRelationId, domainId);
}
record_object_address_dependencies(&conobject, addrs_auto,
@@ -299,17 +309,26 @@ CreateConstraintEntry(const char *constraintName,
if (foreignNKeys > 0)
{
+ bool locked_object = false;
+
for (i = 0; i < foreignNKeys; i++)
{
ObjectAddressSubSet(relobject, RelationRelationId,
foreignRelId, foreignKey[i]);
add_exact_object_address(&relobject, addrs_normal);
+
+ if (!locked_object)
+ {
+ LockNotPinnedObject(RelationRelationId, foreignRelId);
+ locked_object = true;
+ }
}
}
else
{
ObjectAddressSet(relobject, RelationRelationId, foreignRelId);
add_exact_object_address(&relobject, addrs_normal);
+ LockNotPinnedObject(RelationRelationId, foreignRelId);
}
}
@@ -325,6 +344,7 @@ CreateConstraintEntry(const char *constraintName,
ObjectAddressSet(relobject, RelationRelationId, indexRelId);
add_exact_object_address(&relobject, addrs_normal);
+ LockNotPinnedObject(RelationRelationId, indexRelId);
}
if (foreignNKeys > 0)
@@ -344,15 +364,18 @@ CreateConstraintEntry(const char *constraintName,
{
oprobject.objectId = pfEqOp[i];
add_exact_object_address(&oprobject, addrs_normal);
+ LockNotPinnedObject(OperatorRelationId, pfEqOp[i]);
if (ppEqOp[i] != pfEqOp[i])
{
oprobject.objectId = ppEqOp[i];
add_exact_object_address(&oprobject, addrs_normal);
+ LockNotPinnedObject(OperatorRelationId, ppEqOp[i]);
}
if (ffEqOp[i] != pfEqOp[i])
{
oprobject.objectId = ffEqOp[i];
add_exact_object_address(&oprobject, addrs_normal);
+ LockNotPinnedObject(OperatorRelationId, ffEqOp[i]);
}
}
}
@@ -1110,9 +1133,12 @@ ConstraintSetParentConstraint(Oid childConstrId,
ObjectAddressSet(depender, ConstraintRelationId, childConstrId);
ObjectAddressSet(referenced, ConstraintRelationId, parentConstrId);
+ LockNotPinnedObject(ConstraintRelationId, parentConstrId);
recordDependencyOn(&depender, &referenced, DEPENDENCY_PARTITION_PRI);
ObjectAddressSet(referenced, RelationRelationId, childTableId);
+
+ LockNotPinnedObject(RelationRelationId, childTableId);
recordDependencyOn(&depender, &referenced, DEPENDENCY_PARTITION_SEC);
}
else
diff --git a/src/backend/catalog/pg_conversion.c b/src/backend/catalog/pg_conversion.c
index 04cc375cae..5ac365ebd0 100644
--- a/src/backend/catalog/pg_conversion.c
+++ b/src/backend/catalog/pg_conversion.c
@@ -116,12 +116,14 @@ ConversionCreate(const char *conname, Oid connamespace,
referenced.classId = ProcedureRelationId;
referenced.objectId = conproc;
referenced.objectSubId = 0;
+ LockNotPinnedObject(ProcedureRelationId, conproc);
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
/* create dependency on namespace */
referenced.classId = NamespaceRelationId;
referenced.objectId = connamespace;
referenced.objectSubId = 0;
+ LockNotPinnedObject(NamespaceRelationId, connamespace);
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
/* create dependency on owner */
diff --git a/src/backend/catalog/pg_depend.c b/src/backend/catalog/pg_depend.c
index c8b11f887e..fdafffb893 100644
--- a/src/backend/catalog/pg_depend.c
+++ b/src/backend/catalog/pg_depend.c
@@ -20,19 +20,20 @@
#include "catalog/catalog.h"
#include "catalog/dependency.h"
#include "catalog/indexing.h"
+#include "catalog/pg_auth_members.h"
#include "catalog/pg_constraint.h"
#include "catalog/pg_depend.h"
#include "catalog/pg_extension.h"
#include "catalog/partition.h"
#include "commands/extension.h"
#include "miscadmin.h"
+#include "storage/lmgr.h"
+#include "storage/lock.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
-static bool isObjectPinned(const ObjectAddress *object);
-
/*
* Record a dependency between 2 objects via their respective ObjectAddress.
@@ -99,6 +100,37 @@ recordMultipleDependencies(const ObjectAddress *depender,
slot_init_count = 0;
for (i = 0; i < nreferenced; i++, referenced++)
{
+#ifdef USE_ASSERT_CHECKING
+ if (!isObjectPinned(referenced))
+ {
+ if (referenced->classId != RelationRelationId)
+ {
+ LOCKTAG tag;
+
+ SET_LOCKTAG_OBJECT(tag,
+ MyDatabaseId,
+ referenced->classId,
+ referenced->objectId,
+ 0);
+ /* assert the referenced object is locked */
+ Assert(LockHeldByMe(&tag, AccessShareLock, false));
+ }
+ else
+ {
+ Assert(!IsSharedRelation(referenced->objectId));
+
+ /*
+ * Assert the referenced object is locked if it should be
+ * visible (see the comment related to LockNotPinnedObject()
+ * in TypeCreate()).
+ */
+ Assert(!ObjectByIdExist(referenced) ||
+ CheckRelationOidLockedByMe(referenced->objectId,
+ AccessShareLock, true));
+ }
+ }
+#endif
+
/*
* If the referenced object is pinned by the system, there's no real
* need to record dependencies on it. This saves lots of space in
@@ -238,6 +270,7 @@ recordDependencyOnCurrentExtension(const ObjectAddress *object,
extension.objectId = CurrentExtensionObject;
extension.objectSubId = 0;
+ LockNotPinnedObject(ExtensionRelationId, CurrentExtensionObject);
recordDependencyOn(object, &extension, DEPENDENCY_EXTENSION);
}
}
@@ -705,7 +738,7 @@ changeDependenciesOn(Oid refClassId, Oid oldRefObjectId,
* The passed subId, if any, is ignored; we assume that only whole objects
* are pinned (and that this implies pinning their components).
*/
-static bool
+bool
isObjectPinned(const ObjectAddress *object)
{
return IsPinnedObject(object->classId, object->objectId);
diff --git a/src/backend/catalog/pg_operator.c b/src/backend/catalog/pg_operator.c
index bfcfa64346..ba6aa33218 100644
--- a/src/backend/catalog/pg_operator.c
+++ b/src/backend/catalog/pg_operator.c
@@ -251,6 +251,16 @@ OperatorShellMake(const char *operatorName,
values[Anum_pg_operator_oprrest - 1] = ObjectIdGetDatum(InvalidOid);
values[Anum_pg_operator_oprjoin - 1] = ObjectIdGetDatum(InvalidOid);
+ /* Lock dependent objects */
+ if (OidIsValid(operatorNamespace))
+ LockNotPinnedObject(NamespaceRelationId, operatorNamespace);
+
+ if (OidIsValid(leftTypeId))
+ LockNotPinnedObject(TypeRelationId, leftTypeId);
+
+ if (OidIsValid(rightTypeId))
+ LockNotPinnedObject(TypeRelationId, rightTypeId);
+
/*
* create a new operator tuple
*/
@@ -513,6 +523,15 @@ OperatorCreate(const char *operatorName,
CatalogTupleInsert(pg_operator_desc, tup);
}
+ /* Lock dependent objects */
+ LockNotPinnedObject(NamespaceRelationId, operatorNamespace);
+ LockNotPinnedObject(TypeRelationId, leftTypeId);
+ LockNotPinnedObject(TypeRelationId, rightTypeId);
+ LockNotPinnedObject(TypeRelationId, operResultType);
+ LockNotPinnedObject(ProcedureRelationId, procedureId);
+ LockNotPinnedObject(ProcedureRelationId, restrictionId);
+ LockNotPinnedObject(ProcedureRelationId, joinId);
+
/* Add dependencies for the entry */
address = makeOperatorDependencies(tup, true, isUpdate);
diff --git a/src/backend/catalog/pg_proc.c b/src/backend/catalog/pg_proc.c
index fe0490259e..c3999bdce8 100644
--- a/src/backend/catalog/pg_proc.c
+++ b/src/backend/catalog/pg_proc.c
@@ -593,6 +593,13 @@ ProcedureCreate(const char *procedureName,
if (is_update)
deleteDependencyRecordsFor(ProcedureRelationId, retval, true);
+ /*
+ * CommandCounterIncrement() here to ensure the new function entry is
+ * visible when LockNotPinnedObject() will check its existence before
+ * recording the dependencies.
+ */
+ CommandCounterIncrement();
+
addrs = new_object_addresses();
ObjectAddressSet(myself, ProcedureRelationId, retval);
@@ -600,20 +607,24 @@ ProcedureCreate(const char *procedureName,
/* dependency on namespace */
ObjectAddressSet(referenced, NamespaceRelationId, procNamespace);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(NamespaceRelationId, procNamespace);
/* dependency on implementation language */
ObjectAddressSet(referenced, LanguageRelationId, languageObjectId);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(LanguageRelationId, languageObjectId);
/* dependency on return type */
ObjectAddressSet(referenced, TypeRelationId, returnType);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(TypeRelationId, returnType);
/* dependency on transform used by return type, if any */
if ((trfid = get_transform_oid(returnType, languageObjectId, true)))
{
ObjectAddressSet(referenced, TransformRelationId, trfid);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(TransformRelationId, trfid);
}
/* dependency on parameter types */
@@ -621,12 +632,14 @@ ProcedureCreate(const char *procedureName,
{
ObjectAddressSet(referenced, TypeRelationId, allParams[i]);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(TypeRelationId, allParams[i]);
/* dependency on transform used by parameter type, if any */
if ((trfid = get_transform_oid(allParams[i], languageObjectId, true)))
{
ObjectAddressSet(referenced, TransformRelationId, trfid);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(TransformRelationId, trfid);
}
}
@@ -635,6 +648,7 @@ ProcedureCreate(const char *procedureName,
{
ObjectAddressSet(referenced, ProcedureRelationId, prosupport);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(ProcedureRelationId, prosupport);
}
record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
@@ -674,9 +688,6 @@ ProcedureCreate(const char *procedureName,
ArrayType *set_items = NULL;
int save_nestlevel = 0;
- /* Advance command counter so new tuple can be seen by validator */
- CommandCounterIncrement();
-
/*
* Set per-function configuration parameters so that the validation is
* done with the environment the function expects. However, if
diff --git a/src/backend/catalog/pg_publication.c b/src/backend/catalog/pg_publication.c
index b89098f5e9..2d44b8b0e5 100644
--- a/src/backend/catalog/pg_publication.c
+++ b/src/backend/catalog/pg_publication.c
@@ -441,6 +441,7 @@ publication_add_relation(Oid pubid, PublicationRelInfo *pri,
referenced;
List *relids = NIL;
int i;
+ bool locked = false;
rel = table_open(PublicationRelRelationId, RowExclusiveLock);
@@ -503,10 +504,13 @@ publication_add_relation(Oid pubid, PublicationRelInfo *pri,
/* Add dependency on the publication */
ObjectAddressSet(referenced, PublicationRelationId, pubid);
+ LockNotPinnedObject(PublicationRelationId, pubid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
/* Add dependency on the relation */
ObjectAddressSet(referenced, RelationRelationId, relid);
+
+ LockNotPinnedObject(RelationRelationId, relid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
/* Add dependency on the objects mentioned in the qualifications */
@@ -520,6 +524,11 @@ publication_add_relation(Oid pubid, PublicationRelInfo *pri,
while ((i = bms_next_member(attnums, i)) >= 0)
{
ObjectAddressSubSet(referenced, RelationRelationId, relid, i);
+ if (!locked)
+ {
+ LockNotPinnedObject(RelationRelationId, relid);
+ locked = true;
+ }
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
}
@@ -705,10 +714,12 @@ publication_add_schema(Oid pubid, Oid schemaid, bool if_not_exists)
/* Add dependency on the publication */
ObjectAddressSet(referenced, PublicationRelationId, pubid);
+ LockNotPinnedObject(PublicationRelationId, pubid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
/* Add dependency on the schema */
ObjectAddressSet(referenced, NamespaceRelationId, schemaid);
+ LockNotPinnedObject(NamespaceRelationId, schemaid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
/* Close the table */
diff --git a/src/backend/catalog/pg_range.c b/src/backend/catalog/pg_range.c
index 8df73e7ab7..e1538c2146 100644
--- a/src/backend/catalog/pg_range.c
+++ b/src/backend/catalog/pg_range.c
@@ -70,26 +70,31 @@ RangeCreate(Oid rangeTypeOid, Oid rangeSubType, Oid rangeCollation,
ObjectAddressSet(referenced, TypeRelationId, rangeSubType);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(TypeRelationId, rangeSubType);
ObjectAddressSet(referenced, OperatorClassRelationId, rangeSubOpclass);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(OperatorClassRelationId, rangeSubOpclass);
if (OidIsValid(rangeCollation))
{
ObjectAddressSet(referenced, CollationRelationId, rangeCollation);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(CollationRelationId, rangeCollation);
}
if (OidIsValid(rangeCanonical))
{
ObjectAddressSet(referenced, ProcedureRelationId, rangeCanonical);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(ProcedureRelationId, rangeCanonical);
}
if (OidIsValid(rangeSubDiff))
{
ObjectAddressSet(referenced, ProcedureRelationId, rangeSubDiff);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(ProcedureRelationId, rangeSubDiff);
}
record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
@@ -99,6 +104,7 @@ RangeCreate(Oid rangeTypeOid, Oid rangeSubType, Oid rangeCollation,
referencing.classId = TypeRelationId;
referencing.objectId = multirangeTypeOid;
referencing.objectSubId = 0;
+ LockNotPinnedObject(TypeRelationId, rangeTypeOid);
recordDependencyOn(&referencing, &myself, DEPENDENCY_INTERNAL);
table_close(pg_range, RowExclusiveLock);
diff --git a/src/backend/catalog/pg_type.c b/src/backend/catalog/pg_type.c
index b36f81afb9..77ff5f0603 100644
--- a/src/backend/catalog/pg_type.c
+++ b/src/backend/catalog/pg_type.c
@@ -157,6 +157,12 @@ TypeShellMake(const char *typeName, Oid typeNamespace, Oid ownerId)
* Create dependencies. We can/must skip this in bootstrap mode.
*/
if (!IsBootstrapProcessingMode())
+ {
+ /* Lock dependent objects */
+ LockNotPinnedObject(NamespaceRelationId, typeNamespace);
+ LockNotPinnedObject(ProcedureRelationId, F_SHELL_IN);
+ LockNotPinnedObject(ProcedureRelationId, F_SHELL_OUT);
+
GenerateTypeDependencies(tup,
pg_type_desc,
NULL,
@@ -166,6 +172,7 @@ TypeShellMake(const char *typeName, Oid typeNamespace, Oid ownerId)
false,
true, /* make extension dependency */
false);
+ }
/* Post creation hook for new shell type */
InvokeObjectPostCreateHook(TypeRelationId, typoid, 0);
@@ -494,6 +501,37 @@ TypeCreate(Oid newTypeOid,
* Create dependencies. We can/must skip this in bootstrap mode.
*/
if (!IsBootstrapProcessingMode())
+ {
+ /*
+ * CommandCounterIncrement() here to ensure the new type entry is
+ * visible when LockNotPinnedObject() will check its existence before
+ * recording the dependencies.
+ */
+ CommandCounterIncrement();
+
+ /* Lock dependent objects */
+ LockNotPinnedObject(NamespaceRelationId, typeNamespace);
+ LockNotPinnedObject(ProcedureRelationId, inputProcedure);
+ LockNotPinnedObject(ProcedureRelationId, outputProcedure);
+ LockNotPinnedObject(ProcedureRelationId, receiveProcedure);
+ LockNotPinnedObject(ProcedureRelationId, sendProcedure);
+ LockNotPinnedObject(ProcedureRelationId, typmodinProcedure);
+ LockNotPinnedObject(ProcedureRelationId, typmodoutProcedure);
+ LockNotPinnedObject(ProcedureRelationId, analyzeProcedure);
+ LockNotPinnedObject(ProcedureRelationId, subscriptProcedure);
+ LockNotPinnedObject(TypeRelationId, baseType);
+ LockNotPinnedObject(CollationRelationId, typeCollation);
+ LockNotPinnedObject(TypeRelationId, elementType);
+
+ /*
+ * No need to call LockRelationOid() (through LockNotPinnedObject())
+ * on relationOid as relationOid is set to an InvalidOid or to a new
+ * Oid not added to pg_class yet (In heap_create_with_catalog(),
+ * AddNewRelationType() is called before AddNewRelationTuple()).
+ */
+ if (relationKind == RELKIND_COMPOSITE_TYPE)
+ LockNotPinnedObject(TypeRelationId, typeObjectId);
+
GenerateTypeDependencies(tup,
pg_type_desc,
(defaultTypeBin ?
@@ -505,6 +543,7 @@ TypeCreate(Oid newTypeOid,
isDependentType,
true, /* make extension dependency */
rebuildDeps);
+ }
/* Post creation hook for new type */
InvokeObjectPostCreateHook(TypeRelationId, typeObjectId, 0);
diff --git a/src/backend/catalog/toasting.c b/src/backend/catalog/toasting.c
index 874a8fc89a..b8fb22af6a 100644
--- a/src/backend/catalog/toasting.c
+++ b/src/backend/catalog/toasting.c
@@ -383,6 +383,7 @@ create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
toastobject.objectId = toast_relid;
toastobject.objectSubId = 0;
+ LockNotPinnedObject(RelationRelationId, relOid);
recordDependencyOn(&toastobject, &baseobject, DEPENDENCY_INTERNAL);
}
diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c
index 78c1d4e1b8..e068b127c2 100644
--- a/src/backend/commands/alter.c
+++ b/src/backend/commands/alter.c
@@ -499,7 +499,10 @@ ExecAlterObjectDependsStmt(AlterObjectDependsStmt *stmt, ObjectAddress *refAddre
currexts = getAutoExtensionsOfObject(address.classId,
address.objectId);
if (!list_member_oid(currexts, refAddr.objectId))
+ {
+ LockNotPinnedObject(refAddr.classId, refAddr.objectId);
recordDependencyOn(&address, &refAddr, DEPENDENCY_AUTO_EXTENSION);
+ }
}
return address;
@@ -803,6 +806,7 @@ AlterObjectNamespace_internal(Relation rel, Oid objid, Oid nspOid)
pfree(replaces);
/* update dependency to point to the new schema */
+ LockNotPinnedObject(NamespaceRelationId, nspOid);
if (changeDependencyFor(classId, objid,
NamespaceRelationId, oldNspOid, nspOid) != 1)
elog(ERROR, "could not change schema dependency for object %u",
diff --git a/src/backend/commands/amcmds.c b/src/backend/commands/amcmds.c
index 58ed9d216c..eb9b86d563 100644
--- a/src/backend/commands/amcmds.c
+++ b/src/backend/commands/amcmds.c
@@ -104,6 +104,7 @@ CreateAccessMethod(CreateAmStmt *stmt)
referenced.objectId = amhandler;
referenced.objectSubId = 0;
+ LockNotPinnedObject(ProcedureRelationId, amhandler);
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
recordDependencyOnCurrentExtension(&myself, false);
diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c
index effd395086..60b18f9f7c 100644
--- a/src/backend/commands/cluster.c
+++ b/src/backend/commands/cluster.c
@@ -1271,6 +1271,7 @@ swap_relation_files(Oid r1, Oid r2, bool target_is_pg_class,
*/
if (relam1 != relam2)
{
+ LockNotPinnedObject(AccessMethodRelationId, relam2);
if (changeDependencyFor(RelationRelationId,
r1,
AccessMethodRelationId,
@@ -1279,6 +1280,8 @@ swap_relation_files(Oid r1, Oid r2, bool target_is_pg_class,
elog(ERROR, "could not change access method dependency for relation \"%s.%s\"",
get_namespace_name(get_rel_namespace(r1)),
get_rel_name(r1));
+
+ LockNotPinnedObject(AccessMethodRelationId, relam1);
if (changeDependencyFor(RelationRelationId,
r2,
AccessMethodRelationId,
@@ -1380,6 +1383,8 @@ swap_relation_files(Oid r1, Oid r2, bool target_is_pg_class,
{
baseobject.objectId = r1;
toastobject.objectId = relform1->reltoastrelid;
+
+ LockNotPinnedObject(RelationRelationId, r1);
recordDependencyOn(&toastobject, &baseobject,
DEPENDENCY_INTERNAL);
}
@@ -1388,6 +1393,8 @@ swap_relation_files(Oid r1, Oid r2, bool target_is_pg_class,
{
baseobject.objectId = r2;
toastobject.objectId = relform2->reltoastrelid;
+
+ LockNotPinnedObject(RelationRelationId, r2);
recordDependencyOn(&toastobject, &baseobject,
DEPENDENCY_INTERNAL);
}
diff --git a/src/backend/commands/event_trigger.c b/src/backend/commands/event_trigger.c
index edc2c988e2..14dab63ef0 100644
--- a/src/backend/commands/event_trigger.c
+++ b/src/backend/commands/event_trigger.c
@@ -327,6 +327,7 @@ insert_event_trigger_tuple(const char *trigname, const char *eventname, Oid evtO
referenced.classId = ProcedureRelationId;
referenced.objectId = funcoid;
referenced.objectSubId = 0;
+ LockNotPinnedObject(ProcedureRelationId, funcoid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
/* Depend on extension, if any. */
diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
index ba540e3de5..01813ac71d 100644
--- a/src/backend/commands/extension.c
+++ b/src/backend/commands/extension.c
@@ -2035,6 +2035,7 @@ InsertExtensionTuple(const char *extName, Oid extOwner,
ObjectAddressSet(nsp, NamespaceRelationId, schemaOid);
add_exact_object_address(&nsp, refobjs);
+ LockNotPinnedObject(NamespaceRelationId, schemaOid);
foreach(lc, requiredExtensions)
{
@@ -2043,6 +2044,7 @@ InsertExtensionTuple(const char *extName, Oid extOwner,
ObjectAddressSet(otherext, ExtensionRelationId, reqext);
add_exact_object_address(&otherext, refobjs);
+ LockNotPinnedObject(ExtensionRelationId, reqext);
}
/* Record all of them (this includes duplicate elimination) */
@@ -3079,6 +3081,7 @@ AlterExtensionNamespace(const char *extensionName, const char *newschema, Oid *o
table_close(extRel, RowExclusiveLock);
/* update dependency to point to the new schema */
+ LockNotPinnedObject(NamespaceRelationId, nspOid);
if (changeDependencyFor(ExtensionRelationId, extensionOid,
NamespaceRelationId, oldNspOid, nspOid) != 1)
elog(ERROR, "could not change schema dependency for extension %s",
@@ -3369,6 +3372,7 @@ ApplyExtensionUpdates(Oid extensionOid,
otherext.objectId = reqext;
otherext.objectSubId = 0;
+ LockNotPinnedObject(ExtensionRelationId, reqext);
recordDependencyOn(&myself, &otherext, DEPENDENCY_NORMAL);
}
@@ -3525,6 +3529,7 @@ ExecAlterExtensionContentsRecurse(AlterExtensionContentsStmt *stmt,
/*
* OK, add the dependency.
*/
+ LockNotPinnedObject(extension.classId, extension.objectId);
recordDependencyOn(&object, &extension, DEPENDENCY_EXTENSION);
/*
diff --git a/src/backend/commands/foreigncmds.c b/src/backend/commands/foreigncmds.c
index c14e038d54..d6cced22e7 100644
--- a/src/backend/commands/foreigncmds.c
+++ b/src/backend/commands/foreigncmds.c
@@ -642,6 +642,7 @@ CreateForeignDataWrapper(ParseState *pstate, CreateFdwStmt *stmt)
referenced.classId = ProcedureRelationId;
referenced.objectId = fdwhandler;
referenced.objectSubId = 0;
+ LockNotPinnedObject(ProcedureRelationId, fdwhandler);
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
}
@@ -650,6 +651,7 @@ CreateForeignDataWrapper(ParseState *pstate, CreateFdwStmt *stmt)
referenced.classId = ProcedureRelationId;
referenced.objectId = fdwvalidator;
referenced.objectSubId = 0;
+ LockNotPinnedObject(ProcedureRelationId, fdwvalidator);
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
}
@@ -811,6 +813,7 @@ AlterForeignDataWrapper(ParseState *pstate, AlterFdwStmt *stmt)
referenced.classId = ProcedureRelationId;
referenced.objectId = fdwhandler;
referenced.objectSubId = 0;
+ LockNotPinnedObject(ProcedureRelationId, fdwhandler);
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
}
@@ -819,6 +822,7 @@ AlterForeignDataWrapper(ParseState *pstate, AlterFdwStmt *stmt)
referenced.classId = ProcedureRelationId;
referenced.objectId = fdwvalidator;
referenced.objectSubId = 0;
+ LockNotPinnedObject(ProcedureRelationId, fdwvalidator);
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
}
}
@@ -951,6 +955,7 @@ CreateForeignServer(CreateForeignServerStmt *stmt)
referenced.classId = ForeignDataWrapperRelationId;
referenced.objectId = fdw->fdwid;
referenced.objectSubId = 0;
+ LockNotPinnedObject(ForeignDataWrapperRelationId, fdw->fdwid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
recordDependencyOnOwner(ForeignServerRelationId, srvId, ownerId);
@@ -1195,6 +1200,7 @@ CreateUserMapping(CreateUserMappingStmt *stmt)
referenced.classId = ForeignServerRelationId;
referenced.objectId = srv->serverid;
referenced.objectSubId = 0;
+ LockNotPinnedObject(ForeignServerRelationId, srv->serverid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
if (OidIsValid(useId))
@@ -1472,6 +1478,7 @@ CreateForeignTable(CreateForeignTableStmt *stmt, Oid relid)
referenced.classId = ForeignServerRelationId;
referenced.objectId = server->serverid;
referenced.objectSubId = 0;
+ LockNotPinnedObject(ForeignServerRelationId, server->serverid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
table_close(ftrel, RowExclusiveLock);
diff --git a/src/backend/commands/functioncmds.c b/src/backend/commands/functioncmds.c
index b9fd7683ab..e215551147 100644
--- a/src/backend/commands/functioncmds.c
+++ b/src/backend/commands/functioncmds.c
@@ -1461,6 +1461,7 @@ AlterFunction(ParseState *pstate, AlterFunctionStmt *stmt)
/* Add or replace dependency on support function */
if (OidIsValid(procForm->prosupport))
{
+ LockNotPinnedObject(ProcedureRelationId, newsupport);
if (changeDependencyFor(ProcedureRelationId, funcOid,
ProcedureRelationId, procForm->prosupport,
newsupport) != 1)
@@ -1474,6 +1475,7 @@ AlterFunction(ParseState *pstate, AlterFunctionStmt *stmt)
referenced.classId = ProcedureRelationId;
referenced.objectId = newsupport;
referenced.objectSubId = 0;
+ LockNotPinnedObject(ProcedureRelationId, newsupport);
recordDependencyOn(&address, &referenced, DEPENDENCY_NORMAL);
}
@@ -1990,21 +1992,25 @@ CreateTransform(CreateTransformStmt *stmt)
/* dependency on language */
ObjectAddressSet(referenced, LanguageRelationId, langid);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(LanguageRelationId, langid);
/* dependency on type */
ObjectAddressSet(referenced, TypeRelationId, typeid);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(TypeRelationId, typeid);
/* dependencies on functions */
if (OidIsValid(fromsqlfuncid))
{
ObjectAddressSet(referenced, ProcedureRelationId, fromsqlfuncid);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(ProcedureRelationId, fromsqlfuncid);
}
if (OidIsValid(tosqlfuncid))
{
ObjectAddressSet(referenced, ProcedureRelationId, tosqlfuncid);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(ProcedureRelationId, tosqlfuncid);
}
record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index d6e23caef1..ef828df294 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -4524,8 +4524,10 @@ IndexSetParentIndex(Relation partitionIdx, Oid parentOid)
ObjectAddressSet(parentIdx, RelationRelationId, parentOid);
ObjectAddressSet(partitionTbl, RelationRelationId,
partitionIdx->rd_index->indrelid);
+ LockNotPinnedObject(RelationRelationId, parentOid);
recordDependencyOn(&partIdx, &parentIdx,
DEPENDENCY_PARTITION_PRI);
+ LockNotPinnedObject(RelationRelationId, partitionIdx->rd_index->indrelid);
recordDependencyOn(&partIdx, &partitionTbl,
DEPENDENCY_PARTITION_SEC);
}
diff --git a/src/backend/commands/opclasscmds.c b/src/backend/commands/opclasscmds.c
index 2c325badf9..72b347e980 100644
--- a/src/backend/commands/opclasscmds.c
+++ b/src/backend/commands/opclasscmds.c
@@ -299,12 +299,14 @@ CreateOpFamily(CreateOpFamilyStmt *stmt, const char *opfname,
referenced.classId = AccessMethodRelationId;
referenced.objectId = amoid;
referenced.objectSubId = 0;
+ LockNotPinnedObject(AccessMethodRelationId, amoid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
/* dependency on namespace */
referenced.classId = NamespaceRelationId;
referenced.objectId = namespaceoid;
referenced.objectSubId = 0;
+ LockNotPinnedObject(NamespaceRelationId, namespaceoid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
/* dependency on owner */
@@ -726,18 +728,21 @@ DefineOpClass(CreateOpClassStmt *stmt)
referenced.classId = NamespaceRelationId;
referenced.objectId = namespaceoid;
referenced.objectSubId = 0;
+ LockNotPinnedObject(NamespaceRelationId, namespaceoid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
/* dependency on opfamily */
referenced.classId = OperatorFamilyRelationId;
referenced.objectId = opfamilyoid;
referenced.objectSubId = 0;
+ LockNotPinnedObject(OperatorFamilyRelationId, opfamilyoid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
/* dependency on indexed datatype */
referenced.classId = TypeRelationId;
referenced.objectId = typeoid;
referenced.objectSubId = 0;
+ LockNotPinnedObject(TypeRelationId, typeoid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
/* dependency on storage datatype */
@@ -746,6 +751,7 @@ DefineOpClass(CreateOpClassStmt *stmt)
referenced.classId = TypeRelationId;
referenced.objectId = storageoid;
referenced.objectSubId = 0;
+ LockNotPinnedObject(TypeRelationId, storageoid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
}
@@ -1487,6 +1493,13 @@ storeOperators(List *opfamilyname, Oid amoid, Oid opfamilyoid,
heap_freetuple(tup);
+ /*
+ * CommandCounterIncrement() here to ensure the new operator entry is
+ * visible when LockNotPinnedObject() will check its existence before
+ * recording the dependencies.
+ */
+ CommandCounterIncrement();
+
/* Make its dependencies */
myself.classId = AccessMethodOperatorRelationId;
myself.objectId = entryoid;
@@ -1497,6 +1510,7 @@ storeOperators(List *opfamilyname, Oid amoid, Oid opfamilyoid,
referenced.objectSubId = 0;
/* see comments in amapi.h about dependency strength */
+ LockNotPinnedObject(OperatorRelationId, op->object);
recordDependencyOn(&myself, &referenced,
op->ref_is_hard ? DEPENDENCY_NORMAL : DEPENDENCY_AUTO);
@@ -1505,6 +1519,7 @@ storeOperators(List *opfamilyname, Oid amoid, Oid opfamilyoid,
referenced.objectId = op->refobjid;
referenced.objectSubId = 0;
+ LockNotPinnedObject(referenced.classId, op->refobjid);
recordDependencyOn(&myself, &referenced,
op->ref_is_hard ? DEPENDENCY_INTERNAL : DEPENDENCY_AUTO);
@@ -1538,6 +1553,7 @@ storeOperators(List *opfamilyname, Oid amoid, Oid opfamilyoid,
referenced.objectId = op->sortfamily;
referenced.objectSubId = 0;
+ LockNotPinnedObject(OperatorFamilyRelationId, op->sortfamily);
recordDependencyOn(&myself, &referenced,
op->ref_is_hard ? DEPENDENCY_NORMAL : DEPENDENCY_AUTO);
}
@@ -1621,6 +1637,7 @@ storeProcedures(List *opfamilyname, Oid amoid, Oid opfamilyoid,
referenced.objectSubId = 0;
/* see comments in amapi.h about dependency strength */
+ LockNotPinnedObject(ProcedureRelationId, proc->object);
recordDependencyOn(&myself, &referenced,
proc->ref_is_hard ? DEPENDENCY_NORMAL : DEPENDENCY_AUTO);
@@ -1629,6 +1646,7 @@ storeProcedures(List *opfamilyname, Oid amoid, Oid opfamilyoid,
referenced.objectId = proc->refobjid;
referenced.objectSubId = 0;
+ LockNotPinnedObject(referenced.classId, proc->refobjid);
recordDependencyOn(&myself, &referenced,
proc->ref_is_hard ? DEPENDENCY_INTERNAL : DEPENDENCY_AUTO);
diff --git a/src/backend/commands/operatorcmds.c b/src/backend/commands/operatorcmds.c
index 673648f1fc..59a4715fff 100644
--- a/src/backend/commands/operatorcmds.c
+++ b/src/backend/commands/operatorcmds.c
@@ -33,6 +33,7 @@
#include "access/htup_details.h"
#include "access/table.h"
+#include "catalog/dependency.h"
#include "catalog/indexing.h"
#include "catalog/objectaccess.h"
#include "catalog/pg_namespace.h"
@@ -656,11 +657,15 @@ AlterOperator(AlterOperatorStmt *stmt)
{
replaces[Anum_pg_operator_oprrest - 1] = true;
values[Anum_pg_operator_oprrest - 1] = ObjectIdGetDatum(restrictionOid);
+ if (OidIsValid(restrictionOid))
+ LockNotPinnedObject(ProcedureRelationId, restrictionOid);
}
if (updateJoin)
{
replaces[Anum_pg_operator_oprjoin - 1] = true;
values[Anum_pg_operator_oprjoin - 1] = ObjectIdGetDatum(joinOid);
+ if (OidIsValid(joinOid))
+ LockNotPinnedObject(ProcedureRelationId, joinOid);
}
if (OidIsValid(commutatorOid))
{
@@ -688,6 +693,31 @@ AlterOperator(AlterOperatorStmt *stmt)
CatalogTupleUpdate(catalog, &tup->t_self, tup);
+
+ /* Lock dependent objects */
+ oprForm = (Form_pg_operator) GETSTRUCT(tup);
+
+ if (OidIsValid(oprForm->oprnamespace))
+ LockNotPinnedObject(NamespaceRelationId, oprForm->oprnamespace);
+
+ if (OidIsValid(oprForm->oprleft))
+ LockNotPinnedObject(TypeRelationId, oprForm->oprleft);
+
+ if (OidIsValid(oprForm->oprright))
+ LockNotPinnedObject(TypeRelationId, oprForm->oprright);
+
+ if (OidIsValid(oprForm->oprresult))
+ LockNotPinnedObject(TypeRelationId, oprForm->oprresult);
+
+ if (OidIsValid(oprForm->oprcode))
+ LockNotPinnedObject(ProcedureRelationId, oprForm->oprcode);
+
+ if (OidIsValid(oprForm->oprrest))
+ LockNotPinnedObject(ProcedureRelationId, oprForm->oprrest);
+
+ if (OidIsValid(oprForm->oprjoin))
+ LockNotPinnedObject(ProcedureRelationId, oprForm->oprjoin);
+
address = makeOperatorDependencies(tup, false, true);
if (OidIsValid(commutatorOid) || OidIsValid(negatorOid))
diff --git a/src/backend/commands/policy.c b/src/backend/commands/policy.c
index 83056960fe..cf5e194792 100644
--- a/src/backend/commands/policy.c
+++ b/src/backend/commands/policy.c
@@ -722,6 +722,7 @@ CreatePolicy(CreatePolicyStmt *stmt)
myself.objectId = policy_id;
myself.objectSubId = 0;
+ LockNotPinnedObject(RelationRelationId, table_id);
recordDependencyOn(&myself, &target, DEPENDENCY_AUTO);
recordDependencyOnExpr(&myself, qual, qual_pstate->p_rtable,
@@ -1053,6 +1054,7 @@ AlterPolicy(AlterPolicyStmt *stmt)
myself.objectId = policy_id;
myself.objectSubId = 0;
+ LockNotPinnedObject(RelationRelationId, table_id);
recordDependencyOn(&myself, &target, DEPENDENCY_AUTO);
recordDependencyOnExpr(&myself, qual, qual_parse_rtable, DEPENDENCY_NORMAL);
diff --git a/src/backend/commands/proclang.c b/src/backend/commands/proclang.c
index 5036ac0363..f4a7e46b71 100644
--- a/src/backend/commands/proclang.c
+++ b/src/backend/commands/proclang.c
@@ -190,12 +190,14 @@ CreateProceduralLanguage(CreatePLangStmt *stmt)
/* dependency on the PL handler function */
ObjectAddressSet(referenced, ProcedureRelationId, handlerOid);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(ProcedureRelationId, handlerOid);
/* dependency on the inline handler function, if any */
if (OidIsValid(inlineOid))
{
ObjectAddressSet(referenced, ProcedureRelationId, inlineOid);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(ProcedureRelationId, inlineOid);
}
/* dependency on the validator function, if any */
@@ -203,6 +205,7 @@ CreateProceduralLanguage(CreatePLangStmt *stmt)
{
ObjectAddressSet(referenced, ProcedureRelationId, valOid);
add_exact_object_address(&referenced, addrs);
+ LockNotPinnedObject(ProcedureRelationId, valOid);
}
record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
diff --git a/src/backend/commands/sequence.c b/src/backend/commands/sequence.c
index b13ee2b745..31dba914b8 100644
--- a/src/backend/commands/sequence.c
+++ b/src/backend/commands/sequence.c
@@ -1691,6 +1691,8 @@ process_owned_by(Relation seqrel, List *owned_by, bool for_identity)
depobject.classId = RelationRelationId;
depobject.objectId = RelationGetRelid(seqrel);
depobject.objectSubId = 0;
+
+ LockNotPinnedObject(RelationRelationId, RelationGetRelid(tablerel));
recordDependencyOn(&depobject, &refobject, deptype);
}
diff --git a/src/backend/commands/statscmds.c b/src/backend/commands/statscmds.c
index a817821bf6..5b7950d582 100644
--- a/src/backend/commands/statscmds.c
+++ b/src/backend/commands/statscmds.c
@@ -88,6 +88,7 @@ CreateStatistics(CreateStatsStmt *stmt)
bool build_mcv;
bool build_expressions;
bool requested_type = false;
+ bool locked_object = false;
int i;
ListCell *cell;
ListCell *cell2;
@@ -536,6 +537,12 @@ CreateStatistics(CreateStatsStmt *stmt)
for (i = 0; i < nattnums; i++)
{
ObjectAddressSubSet(parentobject, RelationRelationId, relid, attnums[i]);
+
+ if (!locked_object)
+ {
+ LockNotPinnedObject(RelationRelationId, relid);
+ locked_object = true;
+ }
recordDependencyOn(&myself, &parentobject, DEPENDENCY_AUTO);
}
@@ -553,6 +560,8 @@ CreateStatistics(CreateStatsStmt *stmt)
if (!nattnums)
{
ObjectAddressSet(parentobject, RelationRelationId, relid);
+
+ LockNotPinnedObject(RelationRelationId, relid);
recordDependencyOn(&myself, &parentobject, DEPENDENCY_AUTO);
}
@@ -573,6 +582,7 @@ CreateStatistics(CreateStatsStmt *stmt)
* than the underlying table(s).
*/
ObjectAddressSet(parentobject, NamespaceRelationId, namespaceId);
+ LockNotPinnedObject(NamespaceRelationId, namespaceId);
recordDependencyOn(&myself, &parentobject, DEPENDENCY_NORMAL);
recordDependencyOnOwner(StatisticExtRelationId, statoid, stxowner);
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 33ea619224..4797ac5463 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -3499,6 +3499,7 @@ StoreCatalogInheritance1(Oid relationId, Oid parentOid,
childobject.objectId = relationId;
childobject.objectSubId = 0;
+ LockNotPinnedObject(RelationRelationId, parentOid);
recordDependencyOn(&childobject, &parentobject,
child_dependency_type(child_is_partition));
@@ -7401,7 +7402,9 @@ ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel,
/*
* Add needed dependency entries for the new column.
*/
+ LockNotPinnedObject(TypeRelationId, attribute->atttypid);
add_column_datatype_dependency(myrelid, newattnum, attribute->atttypid);
+ LockNotPinnedObject(CollationRelationId, attribute->attcollation);
add_column_collation_dependency(myrelid, newattnum, attribute->attcollation);
/*
@@ -10481,11 +10484,16 @@ addFkConstraint(addFkConstraintSides fkside,
Assert(fkside != addFkBothSides);
if (fkside == addFkReferencedSide)
+ {
+ LockNotPinnedObject(ConstraintRelationId, parentConstr);
recordDependencyOn(&address, &referenced, DEPENDENCY_INTERNAL);
+ }
else
{
+ LockNotPinnedObject(ConstraintRelationId, parentConstr);
recordDependencyOn(&address, &referenced, DEPENDENCY_PARTITION_PRI);
ObjectAddressSet(referenced, RelationRelationId, RelationGetRelid(rel));
+ LockNotPinnedObject(RelationRelationId, RelationGetRelid(rel));
recordDependencyOn(&address, &referenced, DEPENDENCY_PARTITION_SEC);
}
}
@@ -13791,7 +13799,9 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
table_close(attrelation, RowExclusiveLock);
/* Install dependencies on new datatype and collation */
+ LockNotPinnedObject(TypeRelationId, targettype);
add_column_datatype_dependency(RelationGetRelid(rel), attnum, targettype);
+ LockNotPinnedObject(CollationRelationId, targetcollid);
add_column_collation_dependency(RelationGetRelid(rel), attnum, targetcollid);
/*
@@ -15369,6 +15379,7 @@ ATExecSetAccessMethodNoStorage(Relation rel, Oid newAccessMethodId)
*/
ObjectAddressSet(relobj, RelationRelationId, reloid);
ObjectAddressSet(referenced, AccessMethodRelationId, rd_rel->relam);
+ LockNotPinnedObject(AccessMethodRelationId, rd_rel->relam);
recordDependencyOn(&relobj, &referenced, DEPENDENCY_NORMAL);
}
else if (OidIsValid(oldAccessMethodId) &&
@@ -15388,6 +15399,7 @@ ATExecSetAccessMethodNoStorage(Relation rel, Oid newAccessMethodId)
OidIsValid(rd_rel->relam));
/* Both are valid, so update the dependency */
+ LockNotPinnedObject(AccessMethodRelationId, rd_rel->relam);
changeDependencyFor(RelationRelationId, reloid,
AccessMethodRelationId,
oldAccessMethodId, rd_rel->relam);
@@ -17095,6 +17107,7 @@ ATExecAddOf(Relation rel, const TypeName *ofTypename, LOCKMODE lockmode)
typeobj.classId = TypeRelationId;
typeobj.objectId = typeid;
typeobj.objectSubId = 0;
+ LockNotPinnedObject(TypeRelationId, typeid);
recordDependencyOn(&tableobj, &typeobj, DEPENDENCY_NORMAL);
/* Update pg_class.reloftype */
@@ -17867,14 +17880,17 @@ AlterRelationNamespaceInternal(Relation classRel, Oid relOid,
/* Update dependency on schema if caller said so */
- if (hasDependEntry &&
- changeDependencyFor(RelationRelationId,
+ if (hasDependEntry)
+ {
+ LockNotPinnedObject(NamespaceRelationId, newNspOid);
+ if (changeDependencyFor(RelationRelationId,
relOid,
NamespaceRelationId,
oldNspOid,
newNspOid) != 1)
- elog(ERROR, "could not change schema dependency for relation \"%s\"",
- NameStr(classForm->relname));
+ elog(ERROR, "could not change schema dependency for relation \"%s\"",
+ NameStr(classForm->relname));
+ }
}
else
UnlockTuple(classRel, &classTup->t_self, InplaceUpdateTupleLock);
diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c
index 32f25f4d91..a4db8a8f67 100644
--- a/src/backend/commands/trigger.c
+++ b/src/backend/commands/trigger.c
@@ -1019,8 +1019,6 @@ CreateTriggerFiringOn(CreateTrigStmt *stmt, const char *queryString,
((Form_pg_class) GETSTRUCT(tuple))->relhastriggers = true;
CatalogTupleUpdate(pgrel, &tuple->t_self, tuple);
-
- CommandCounterIncrement();
}
else
CacheInvalidateRelcacheByTuple(tuple);
@@ -1028,6 +1026,13 @@ CreateTriggerFiringOn(CreateTrigStmt *stmt, const char *queryString,
heap_freetuple(tuple);
table_close(pgrel, RowExclusiveLock);
+ /*
+ * CommandCounterIncrement() here to ensure the new trigger entry is
+ * visible when LockNotPinnedObject() will check its existence before
+ * recording the dependencies.
+ */
+ CommandCounterIncrement();
+
/*
* If we're replacing a trigger, flush all the old dependencies before
* recording new ones.
@@ -1046,6 +1051,7 @@ CreateTriggerFiringOn(CreateTrigStmt *stmt, const char *queryString,
referenced.classId = ProcedureRelationId;
referenced.objectId = funcoid;
referenced.objectSubId = 0;
+ LockNotPinnedObject(ProcedureRelationId, funcoid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
if (isInternal && OidIsValid(constraintOid))
@@ -1059,6 +1065,7 @@ CreateTriggerFiringOn(CreateTrigStmt *stmt, const char *queryString,
referenced.classId = ConstraintRelationId;
referenced.objectId = constraintOid;
referenced.objectSubId = 0;
+ LockNotPinnedObject(ConstraintRelationId, constraintOid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_INTERNAL);
}
else
@@ -1071,6 +1078,8 @@ CreateTriggerFiringOn(CreateTrigStmt *stmt, const char *queryString,
referenced.classId = RelationRelationId;
referenced.objectId = RelationGetRelid(rel);
referenced.objectSubId = 0;
+
+ LockNotPinnedObject(RelationRelationId, RelationGetRelid(rel));
recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
if (OidIsValid(constrrelid))
@@ -1078,6 +1087,8 @@ CreateTriggerFiringOn(CreateTrigStmt *stmt, const char *queryString,
referenced.classId = RelationRelationId;
referenced.objectId = constrrelid;
referenced.objectSubId = 0;
+
+ LockNotPinnedObject(RelationRelationId, constrrelid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
}
/* Not possible to have an index dependency in this case */
@@ -1092,6 +1103,7 @@ CreateTriggerFiringOn(CreateTrigStmt *stmt, const char *queryString,
referenced.classId = ConstraintRelationId;
referenced.objectId = constraintOid;
referenced.objectSubId = 0;
+ LockNotPinnedObject(TriggerRelationId, trigoid);
recordDependencyOn(&referenced, &myself, DEPENDENCY_INTERNAL);
}
@@ -1101,8 +1113,11 @@ CreateTriggerFiringOn(CreateTrigStmt *stmt, const char *queryString,
if (OidIsValid(parentTriggerOid))
{
ObjectAddressSet(referenced, TriggerRelationId, parentTriggerOid);
+ LockNotPinnedObject(TriggerRelationId, parentTriggerOid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_PARTITION_PRI);
ObjectAddressSet(referenced, RelationRelationId, RelationGetRelid(rel));
+
+ LockNotPinnedObject(RelationRelationId, RelationGetRelid(rel));
recordDependencyOn(&myself, &referenced, DEPENDENCY_PARTITION_SEC);
}
}
@@ -1111,12 +1126,19 @@ CreateTriggerFiringOn(CreateTrigStmt *stmt, const char *queryString,
if (columns != NULL)
{
int i;
+ bool locked_object = false;
referenced.classId = RelationRelationId;
referenced.objectId = RelationGetRelid(rel);
for (i = 0; i < ncolumns; i++)
{
referenced.objectSubId = columns[i];
+
+ if (!locked_object)
+ {
+ LockNotPinnedObject(RelationRelationId, RelationGetRelid(rel));
+ locked_object = true;
+ }
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
}
}
@@ -1256,9 +1278,12 @@ TriggerSetParentTrigger(Relation trigRel,
ObjectAddressSet(depender, TriggerRelationId, childTrigId);
ObjectAddressSet(referenced, TriggerRelationId, parentTrigId);
+ LockNotPinnedObject(TriggerRelationId, parentTrigId);
recordDependencyOn(&depender, &referenced, DEPENDENCY_PARTITION_PRI);
ObjectAddressSet(referenced, RelationRelationId, childTableId);
+
+ LockNotPinnedObject(RelationRelationId, childTableId);
recordDependencyOn(&depender, &referenced, DEPENDENCY_PARTITION_SEC);
}
else
diff --git a/src/backend/commands/tsearchcmds.c b/src/backend/commands/tsearchcmds.c
index ab16d42ad5..e36c3da102 100644
--- a/src/backend/commands/tsearchcmds.c
+++ b/src/backend/commands/tsearchcmds.c
@@ -214,6 +214,7 @@ DefineTSParser(List *names, List *parameters)
namestrcpy(&pname, prsname);
values[Anum_pg_ts_parser_prsname - 1] = NameGetDatum(&pname);
values[Anum_pg_ts_parser_prsnamespace - 1] = ObjectIdGetDatum(namespaceoid);
+ LockNotPinnedObject(NamespaceRelationId, namespaceoid);
/*
* loop over the definition list and extract the information we need.
@@ -224,28 +225,48 @@ DefineTSParser(List *names, List *parameters)
if (strcmp(defel->defname, "start") == 0)
{
+ Oid procoid;
+
values[Anum_pg_ts_parser_prsstart - 1] =
get_ts_parser_func(defel, Anum_pg_ts_parser_prsstart);
+ procoid = DatumGetObjectId(values[Anum_pg_ts_parser_prsstart - 1]);
+ LockNotPinnedObject(ProcedureRelationId, procoid);
}
else if (strcmp(defel->defname, "gettoken") == 0)
{
+ Oid procoid;
+
values[Anum_pg_ts_parser_prstoken - 1] =
get_ts_parser_func(defel, Anum_pg_ts_parser_prstoken);
+ procoid = DatumGetObjectId(values[Anum_pg_ts_parser_prstoken - 1]);
+ LockNotPinnedObject(ProcedureRelationId, procoid);
}
else if (strcmp(defel->defname, "end") == 0)
{
+ Oid procoid;
+
values[Anum_pg_ts_parser_prsend - 1] =
get_ts_parser_func(defel, Anum_pg_ts_parser_prsend);
+ procoid = DatumGetObjectId(values[Anum_pg_ts_parser_prsend - 1]);
+ LockNotPinnedObject(ProcedureRelationId, procoid);
}
else if (strcmp(defel->defname, "headline") == 0)
{
+ Oid procoid;
+
values[Anum_pg_ts_parser_prsheadline - 1] =
get_ts_parser_func(defel, Anum_pg_ts_parser_prsheadline);
+ procoid = DatumGetObjectId(values[Anum_pg_ts_parser_prsheadline - 1]);
+ LockNotPinnedObject(ProcedureRelationId, procoid);
}
else if (strcmp(defel->defname, "lextypes") == 0)
{
+ Oid procoid;
+
values[Anum_pg_ts_parser_prslextype - 1] =
get_ts_parser_func(defel, Anum_pg_ts_parser_prslextype);
+ procoid = DatumGetObjectId(values[Anum_pg_ts_parser_prslextype - 1]);
+ LockNotPinnedObject(ProcedureRelationId, procoid);
}
else
ereport(ERROR,
@@ -474,6 +495,10 @@ DefineTSDictionary(List *names, List *parameters)
CatalogTupleInsert(dictRel, tup);
+ /* Lock dependent objects */
+ LockNotPinnedObject(NamespaceRelationId, namespaceoid);
+ LockNotPinnedObject(TSTemplateRelationId, templId);
+
address = makeDictionaryDependencies(tup);
/* Post creation hook for new text search dictionary */
@@ -723,6 +748,7 @@ DefineTSTemplate(List *names, List *parameters)
namestrcpy(&dname, tmplname);
values[Anum_pg_ts_template_tmplname - 1] = NameGetDatum(&dname);
values[Anum_pg_ts_template_tmplnamespace - 1] = ObjectIdGetDatum(namespaceoid);
+ LockNotPinnedObject(NamespaceRelationId, namespaceoid);
/*
* loop over the definition list and extract the information we need.
@@ -733,15 +759,23 @@ DefineTSTemplate(List *names, List *parameters)
if (strcmp(defel->defname, "init") == 0)
{
+ Oid procoid;
+
values[Anum_pg_ts_template_tmplinit - 1] =
get_ts_template_func(defel, Anum_pg_ts_template_tmplinit);
nulls[Anum_pg_ts_template_tmplinit - 1] = false;
+ procoid = DatumGetObjectId(values[Anum_pg_ts_template_tmplinit - 1]);
+ LockNotPinnedObject(ProcedureRelationId, procoid);
}
else if (strcmp(defel->defname, "lexize") == 0)
{
+ Oid procoid;
+
values[Anum_pg_ts_template_tmpllexize - 1] =
get_ts_template_func(defel, Anum_pg_ts_template_tmpllexize);
nulls[Anum_pg_ts_template_tmpllexize - 1] = false;
+ procoid = DatumGetObjectId(values[Anum_pg_ts_template_tmpllexize - 1]);
+ LockNotPinnedObject(ProcedureRelationId, procoid);
}
else
ereport(ERROR,
@@ -998,6 +1032,10 @@ DefineTSConfiguration(List *names, List *parameters, ObjectAddress *copied)
values[Anum_pg_ts_config_cfgowner - 1] = ObjectIdGetDatum(GetUserId());
values[Anum_pg_ts_config_cfgparser - 1] = ObjectIdGetDatum(prsOid);
+ /* Lock dependent objects */
+ LockNotPinnedObject(NamespaceRelationId, namespaceoid);
+ LockNotPinnedObject(TSParserRelationId, prsOid);
+
tup = heap_form_tuple(cfgRel->rd_att, values, nulls);
CatalogTupleInsert(cfgRel, tup);
@@ -1063,6 +1101,7 @@ DefineTSConfiguration(List *names, List *parameters, ObjectAddress *copied)
slot[slot_stored_count]->tts_values[Anum_pg_ts_config_map_mapseqno - 1] = cfgmap->mapseqno;
slot[slot_stored_count]->tts_values[Anum_pg_ts_config_map_mapdict - 1] = cfgmap->mapdict;
+ LockNotPinnedObject(TSDictionaryRelationId, cfgmap->mapdict);
ExecStoreVirtualTuple(slot[slot_stored_count]);
slot_stored_count++;
@@ -1156,9 +1195,13 @@ ObjectAddress
AlterTSConfiguration(AlterTSConfigurationStmt *stmt)
{
HeapTuple tup;
+ Form_pg_ts_config cfg;
Oid cfgId;
Relation relMap;
ObjectAddress address;
+ ScanKeyData skey;
+ SysScanDesc scan;
+ HeapTuple maptup;
/* Find the configuration */
tup = GetTSConfigTuple(stmt->cfgname);
@@ -1168,7 +1211,8 @@ AlterTSConfiguration(AlterTSConfigurationStmt *stmt)
errmsg("text search configuration \"%s\" does not exist",
NameListToString(stmt->cfgname))));
- cfgId = ((Form_pg_ts_config) GETSTRUCT(tup))->oid;
+ cfg = (Form_pg_ts_config) GETSTRUCT(tup);
+ cfgId = cfg->oid;
/* must be owner */
if (!object_ownercheck(TSConfigRelationId, cfgId, GetUserId()))
@@ -1183,6 +1227,28 @@ AlterTSConfiguration(AlterTSConfigurationStmt *stmt)
else if (stmt->tokentype)
DropConfigurationMapping(stmt, tup, relMap);
+ /* Lock dependent objects */
+
+ ScanKeyInit(&skey,
+ Anum_pg_ts_config_map_mapcfg,
+ BTEqualStrategyNumber, F_OIDEQ,
+ ObjectIdGetDatum(cfgId));
+
+ scan = systable_beginscan(relMap, TSConfigMapIndexId, true,
+ NULL, 1, &skey);
+
+ while (HeapTupleIsValid((maptup = systable_getnext(scan))))
+ {
+ Form_pg_ts_config_map cfgmap = (Form_pg_ts_config_map) GETSTRUCT(maptup);
+
+ LockNotPinnedObject(TSDictionaryRelationId, cfgmap->mapdict);
+ }
+
+ systable_endscan(scan);
+
+ LockNotPinnedObject(NamespaceRelationId, cfg->cfgnamespace);
+ LockNotPinnedObject(TSParserRelationId, cfg->cfgparser);
+
/* Update dependencies */
makeConfigurationDependencies(tup, true, relMap);
@@ -1414,6 +1480,8 @@ MakeConfigurationMapping(AlterTSConfigurationStmt *stmt,
repl_val[Anum_pg_ts_config_map_mapdict - 1] = ObjectIdGetDatum(dictNew);
repl_repl[Anum_pg_ts_config_map_mapdict - 1] = true;
+ LockNotPinnedObject(TSDictionaryRelationId, dictNew);
+
newtup = heap_modify_tuple(maptup,
RelationGetDescr(relMap),
repl_val, repl_null, repl_repl);
@@ -1456,6 +1524,9 @@ MakeConfigurationMapping(AlterTSConfigurationStmt *stmt,
slot[slotCount]->tts_values[Anum_pg_ts_config_map_mapseqno - 1] = Int32GetDatum(j + 1);
slot[slotCount]->tts_values[Anum_pg_ts_config_map_mapdict - 1] = ObjectIdGetDatum(dictIds[j]);
+ /* Lock dependent objects */
+ LockNotPinnedObject(TSDictionaryRelationId, dictIds[j]);
+
ExecStoreVirtualTuple(slot[slotCount]);
slotCount++;
diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c
index 6b1d238351..2059df09fd 100644
--- a/src/backend/commands/typecmds.c
+++ b/src/backend/commands/typecmds.c
@@ -1812,6 +1812,7 @@ makeRangeConstructors(const char *name, Oid namespace,
* that they go away silently when the type is dropped. Note that
* pg_dump depends on this choice to avoid dumping the constructors.
*/
+ LockNotPinnedObject(TypeRelationId, rangeOid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_INTERNAL);
}
}
@@ -1877,6 +1878,7 @@ makeMultirangeConstructors(const char *name, Oid namespace,
* that they go away silently when the type is dropped. Note that pg_dump
* depends on this choice to avoid dumping the constructors.
*/
+ LockNotPinnedObject(TypeRelationId, multirangeOid);
recordDependencyOn(&myself, &referenced, DEPENDENCY_INTERNAL);
pfree(argtypes);
@@ -2690,6 +2692,45 @@ AlterDomainDefault(List *names, Node *defaultRaw)
CatalogTupleUpdate(rel, &tup->t_self, newtuple);
+ /* Lock dependent objects */
+ typTup = (Form_pg_type) GETSTRUCT(newtuple);
+
+ if (OidIsValid(typTup->typnamespace))
+ LockNotPinnedObject(NamespaceRelationId, typTup->typnamespace);
+
+ if (OidIsValid(typTup->typinput))
+ LockNotPinnedObject(ProcedureRelationId, typTup->typinput);
+
+ if (OidIsValid(typTup->typoutput))
+ LockNotPinnedObject(ProcedureRelationId, typTup->typoutput);
+
+ if (OidIsValid(typTup->typreceive))
+ LockNotPinnedObject(ProcedureRelationId, typTup->typreceive);
+
+ if (OidIsValid(typTup->typsend))
+ LockNotPinnedObject(ProcedureRelationId, typTup->typsend);
+
+ if (OidIsValid(typTup->typmodin))
+ LockNotPinnedObject(ProcedureRelationId, typTup->typmodin);
+
+ if (OidIsValid(typTup->typmodout))
+ LockNotPinnedObject(ProcedureRelationId, typTup->typmodout);
+
+ if (OidIsValid(typTup->typanalyze))
+ LockNotPinnedObject(ProcedureRelationId, typTup->typanalyze);
+
+ if (OidIsValid(typTup->typsubscript))
+ LockNotPinnedObject(ProcedureRelationId, typTup->typsubscript);
+
+ if (OidIsValid(typTup->typbasetype))
+ LockNotPinnedObject(TypeRelationId, typTup->typbasetype);
+
+ if (OidIsValid(typTup->typcollation))
+ LockNotPinnedObject(CollationRelationId, typTup->typcollation);
+
+ if (OidIsValid(typTup->typelem))
+ LockNotPinnedObject(TypeRelationId, typTup->typelem);
+
/* Rebuild dependencies */
GenerateTypeDependencies(newtuple,
rel,
@@ -4296,10 +4337,13 @@ AlterTypeNamespaceInternal(Oid typeOid, Oid nspOid,
if (oldNspOid != nspOid &&
(isCompositeType || typform->typtype != TYPTYPE_COMPOSITE) &&
!isImplicitArray)
+ {
+ LockNotPinnedObject(NamespaceRelationId, nspOid);
if (changeDependencyFor(TypeRelationId, typeOid,
NamespaceRelationId, oldNspOid, nspOid) != 1)
elog(ERROR, "could not change schema dependency for type \"%s\"",
format_type_be(typeOid));
+ }
InvokeObjectPostAlterHook(TypeRelationId, typeOid, 0);
@@ -4591,6 +4635,7 @@ AlterTypeRecurse(Oid typeOid, bool isImplicitArray,
SysScanDesc scan;
ScanKeyData key[1];
HeapTuple domainTup;
+ Form_pg_type typeForm;
/* Since this function recurses, it could be driven to stack overflow */
check_stack_depth();
@@ -4639,6 +4684,45 @@ AlterTypeRecurse(Oid typeOid, bool isImplicitArray,
newtup = heap_modify_tuple(tup, RelationGetDescr(catalog),
values, nulls, replaces);
+ /* Lock dependent objects */
+ typeForm = (Form_pg_type) GETSTRUCT(newtup);
+
+ if (OidIsValid(typeForm->typnamespace))
+ LockNotPinnedObject(NamespaceRelationId, typeForm->typnamespace);
+
+ if (OidIsValid(typeForm->typinput))
+ LockNotPinnedObject(ProcedureRelationId, typeForm->typinput);
+
+ if (OidIsValid(typeForm->typoutput))
+ LockNotPinnedObject(ProcedureRelationId, typeForm->typoutput);
+
+ if (OidIsValid(typeForm->typreceive))
+ LockNotPinnedObject(ProcedureRelationId, typeForm->typreceive);
+
+ if (OidIsValid(typeForm->typsend))
+ LockNotPinnedObject(ProcedureRelationId, typeForm->typsend);
+
+ if (OidIsValid(typeForm->typmodin))
+ LockNotPinnedObject(ProcedureRelationId, typeForm->typmodin);
+
+ if (OidIsValid(typeForm->typmodout))
+ LockNotPinnedObject(ProcedureRelationId, typeForm->typmodout);
+
+ if (OidIsValid(typeForm->typanalyze))
+ LockNotPinnedObject(ProcedureRelationId, typeForm->typanalyze);
+
+ if (OidIsValid(typeForm->typsubscript))
+ LockNotPinnedObject(ProcedureRelationId, typeForm->typsubscript);
+
+ if (OidIsValid(typeForm->typbasetype))
+ LockNotPinnedObject(TypeRelationId, typeForm->typbasetype);
+
+ if (OidIsValid(typeForm->typcollation))
+ LockNotPinnedObject(CollationRelationId, typeForm->typcollation);
+
+ if (OidIsValid(typeForm->typelem))
+ LockNotPinnedObject(TypeRelationId, typeForm->typelem);
+
CatalogTupleUpdate(catalog, &newtup->t_self, newtup);
/* Rebuild dependencies for this type */
diff --git a/src/backend/rewrite/rewriteDefine.c b/src/backend/rewrite/rewriteDefine.c
index 8aa90b0d6f..14a6468efc 100644
--- a/src/backend/rewrite/rewriteDefine.c
+++ b/src/backend/rewrite/rewriteDefine.c
@@ -155,6 +155,7 @@ InsertRule(const char *rulname,
referenced.objectId = eventrel_oid;
referenced.objectSubId = 0;
+ LockNotPinnedObject(RelationRelationId, eventrel_oid);
recordDependencyOn(&myself, &referenced,
(evtype == CMD_SELECT) ? DEPENDENCY_INTERNAL : DEPENDENCY_AUTO);
diff --git a/src/backend/utils/errcodes.txt b/src/backend/utils/errcodes.txt
index c96aa7c49e..c664ae4977 100644
--- a/src/backend/utils/errcodes.txt
+++ b/src/backend/utils/errcodes.txt
@@ -277,6 +277,7 @@ Section: Class 28 - Invalid Authorization Specification
Section: Class 2B - Dependent Privilege Descriptors Still Exist
2B000 E ERRCODE_DEPENDENT_PRIVILEGE_DESCRIPTORS_STILL_EXIST dependent_privilege_descriptors_still_exist
+2BP02 E ERRCODE_DEPENDENT_OBJECTS_DOES_NOT_EXIST dependent_objects_does_not_exist
2BP01 E ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST dependent_objects_still_exist
Section: Class 2D - Invalid Transaction Termination
diff --git a/src/include/catalog/dependency.h b/src/include/catalog/dependency.h
index 0ea7ccf524..73ee2c6a78 100644
--- a/src/include/catalog/dependency.h
+++ b/src/include/catalog/dependency.h
@@ -101,6 +101,8 @@ typedef struct ObjectAddresses ObjectAddresses;
/* in dependency.c */
extern void AcquireDeletionLock(const ObjectAddress *object, int flags);
+extern void LockNotPinnedObjectById(const ObjectAddress *object);
+extern void LockNotPinnedObject(Oid classid, Oid objid);
extern void ReleaseDeletionLock(const ObjectAddress *object);
@@ -172,6 +174,7 @@ extern long changeDependenciesOf(Oid classId, Oid oldObjectId,
extern long changeDependenciesOn(Oid refClassId, Oid oldRefObjectId,
Oid newRefObjectId);
+extern bool isObjectPinned(const ObjectAddress *object);
extern Oid getExtensionOfObject(Oid classId, Oid objectId);
extern List *getAutoExtensionsOfObject(Oid classId, Oid objectId);
diff --git a/src/include/catalog/objectaddress.h b/src/include/catalog/objectaddress.h
index 630434b73c..34d5428433 100644
--- a/src/include/catalog/objectaddress.h
+++ b/src/include/catalog/objectaddress.h
@@ -53,6 +53,7 @@ extern void check_object_ownership(Oid roleid,
Node *object, Relation relation);
extern Oid get_object_namespace(const ObjectAddress *address);
+extern bool ObjectByIdExist(const ObjectAddress *address);
extern bool is_objectclass_supported(Oid class_id);
extern const char *get_object_class_descr(Oid class_id);
diff --git a/src/test/isolation/expected/test_dependencies_locks.out b/src/test/isolation/expected/test_dependencies_locks.out
new file mode 100644
index 0000000000..9b645d7aa5
--- /dev/null
+++ b/src/test/isolation/expected/test_dependencies_locks.out
@@ -0,0 +1,129 @@
+Parsed test spec with 2 sessions
+
+starting permutation: s1_begin s1_create_function_in_schema s2_drop_schema s1_commit
+step s1_begin: BEGIN;
+step s1_create_function_in_schema: CREATE FUNCTION testschema.foo() RETURNS int AS 'select 1' LANGUAGE sql;
+step s2_drop_schema: DROP SCHEMA testschema; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_schema: <... completed>
+ERROR: cannot drop schema testschema because other objects depend on it
+
+starting permutation: s2_begin s2_drop_schema s1_create_function_in_schema s2_commit
+step s2_begin: BEGIN;
+step s2_drop_schema: DROP SCHEMA testschema;
+step s1_create_function_in_schema: CREATE FUNCTION testschema.foo() RETURNS int AS 'select 1' LANGUAGE sql; <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_function_in_schema: <... completed>
+ERROR: schema testschema does not exist
+
+starting permutation: s1_begin s1_alter_function_schema s2_drop_alterschema s1_commit
+step s1_begin: BEGIN;
+step s1_alter_function_schema: ALTER FUNCTION public.falter() SET SCHEMA alterschema;
+step s2_drop_alterschema: DROP SCHEMA alterschema; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_alterschema: <... completed>
+ERROR: cannot drop schema alterschema because other objects depend on it
+
+starting permutation: s2_begin s2_drop_alterschema s1_alter_function_schema s2_commit
+step s2_begin: BEGIN;
+step s2_drop_alterschema: DROP SCHEMA alterschema;
+step s1_alter_function_schema: ALTER FUNCTION public.falter() SET SCHEMA alterschema; <waiting ...>
+step s2_commit: COMMIT;
+step s1_alter_function_schema: <... completed>
+ERROR: schema alterschema does not exist
+
+starting permutation: s1_begin s1_create_function_with_argtype s2_drop_foo_type s1_commit
+step s1_begin: BEGIN;
+step s1_create_function_with_argtype: CREATE FUNCTION fooargtype(num foo) RETURNS int AS 'select 1' LANGUAGE sql;
+step s2_drop_foo_type: DROP TYPE public.foo; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_foo_type: <... completed>
+ERROR: cannot drop type foo because other objects depend on it
+
+starting permutation: s2_begin s2_drop_foo_type s1_create_function_with_argtype s2_commit
+step s2_begin: BEGIN;
+step s2_drop_foo_type: DROP TYPE public.foo;
+step s1_create_function_with_argtype: CREATE FUNCTION fooargtype(num foo) RETURNS int AS 'select 1' LANGUAGE sql; <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_function_with_argtype: <... completed>
+ERROR: type foo does not exist
+
+starting permutation: s1_begin s1_create_function_with_rettype s2_drop_foo_rettype s1_commit
+step s1_begin: BEGIN;
+step s1_create_function_with_rettype: CREATE FUNCTION footrettype() RETURNS id LANGUAGE sql RETURN 1;
+step s2_drop_foo_rettype: DROP DOMAIN id; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_foo_rettype: <... completed>
+ERROR: cannot drop type id because other objects depend on it
+
+starting permutation: s2_begin s2_drop_foo_rettype s1_create_function_with_rettype s2_commit
+step s2_begin: BEGIN;
+step s2_drop_foo_rettype: DROP DOMAIN id;
+step s1_create_function_with_rettype: CREATE FUNCTION footrettype() RETURNS id LANGUAGE sql RETURN 1; <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_function_with_rettype: <... completed>
+ERROR: type id does not exist
+
+starting permutation: s1_begin s1_create_function_with_function s2_drop_function_f s1_commit
+step s1_begin: BEGIN;
+step s1_create_function_with_function: CREATE FUNCTION foofunc() RETURNS int LANGUAGE SQL RETURN f() + 1;
+step s2_drop_function_f: DROP FUNCTION f(); <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_function_f: <... completed>
+ERROR: cannot drop function f() because other objects depend on it
+
+starting permutation: s2_begin s2_drop_function_f s1_create_function_with_function s2_commit
+step s2_begin: BEGIN;
+step s2_drop_function_f: DROP FUNCTION f();
+step s1_create_function_with_function: CREATE FUNCTION foofunc() RETURNS int LANGUAGE SQL RETURN f() + 1; <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_function_with_function: <... completed>
+ERROR: function f() does not exist
+
+starting permutation: s1_begin s1_create_domain_with_domain s2_drop_domain_id s1_commit
+step s1_begin: BEGIN;
+step s1_create_domain_with_domain: CREATE DOMAIN idid as id;
+step s2_drop_domain_id: DROP DOMAIN id; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_domain_id: <... completed>
+ERROR: cannot drop type id because other objects depend on it
+
+starting permutation: s2_begin s2_drop_domain_id s1_create_domain_with_domain s2_commit
+step s2_begin: BEGIN;
+step s2_drop_domain_id: DROP DOMAIN id;
+step s1_create_domain_with_domain: CREATE DOMAIN idid as id; <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_domain_with_domain: <... completed>
+ERROR: type id does not exist
+
+starting permutation: s1_begin s1_create_table_with_type s2_drop_footab_type s1_commit
+step s1_begin: BEGIN;
+step s1_create_table_with_type: CREATE TABLE tabtype(a footab);
+step s2_drop_footab_type: DROP TYPE public.footab; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_footab_type: <... completed>
+ERROR: cannot drop type footab because other objects depend on it
+
+starting permutation: s2_begin s2_drop_footab_type s1_create_table_with_type s2_commit
+step s2_begin: BEGIN;
+step s2_drop_footab_type: DROP TYPE public.footab;
+step s1_create_table_with_type: CREATE TABLE tabtype(a footab); <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_table_with_type: <... completed>
+ERROR: type footab does not exist
+
+starting permutation: s1_begin s1_create_server_with_fdw_wrapper s2_drop_fdw_wrapper s1_commit
+step s1_begin: BEGIN;
+step s1_create_server_with_fdw_wrapper: CREATE SERVER srv_fdw_wrapper FOREIGN DATA WRAPPER fdw_wrapper;
+step s2_drop_fdw_wrapper: DROP FOREIGN DATA WRAPPER fdw_wrapper RESTRICT; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_fdw_wrapper: <... completed>
+ERROR: cannot drop foreign-data wrapper fdw_wrapper because other objects depend on it
+
+starting permutation: s2_begin s2_drop_fdw_wrapper s1_create_server_with_fdw_wrapper s2_commit
+step s2_begin: BEGIN;
+step s2_drop_fdw_wrapper: DROP FOREIGN DATA WRAPPER fdw_wrapper RESTRICT;
+step s1_create_server_with_fdw_wrapper: CREATE SERVER srv_fdw_wrapper FOREIGN DATA WRAPPER fdw_wrapper; <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_server_with_fdw_wrapper: <... completed>
+ERROR: foreign-data wrapper fdw_wrapper does not exist
diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule
index 143109aa4d..0e80dfecfb 100644
--- a/src/test/isolation/isolation_schedule
+++ b/src/test/isolation/isolation_schedule
@@ -115,3 +115,4 @@ test: serializable-parallel-2
test: serializable-parallel-3
test: matview-write-skew
test: lock-nowait
+test: test_dependencies_locks
diff --git a/src/test/isolation/specs/test_dependencies_locks.spec b/src/test/isolation/specs/test_dependencies_locks.spec
new file mode 100644
index 0000000000..5d04dfe9dc
--- /dev/null
+++ b/src/test/isolation/specs/test_dependencies_locks.spec
@@ -0,0 +1,89 @@
+setup
+{
+ CREATE SCHEMA testschema;
+ CREATE SCHEMA alterschema;
+ CREATE TYPE public.foo as enum ('one', 'two');
+ CREATE TYPE public.footab as enum ('three', 'four');
+ CREATE DOMAIN id AS int;
+ CREATE FUNCTION f() RETURNS int LANGUAGE SQL RETURN 1;
+ CREATE FUNCTION public.falter() RETURNS int LANGUAGE SQL RETURN 1;
+ CREATE FOREIGN DATA WRAPPER fdw_wrapper;
+}
+
+teardown
+{
+ DROP FUNCTION IF EXISTS testschema.foo();
+ DROP FUNCTION IF EXISTS fooargtype(num foo);
+ DROP FUNCTION IF EXISTS footrettype();
+ DROP FUNCTION IF EXISTS foofunc();
+ DROP FUNCTION IF EXISTS public.falter();
+ DROP FUNCTION IF EXISTS alterschema.falter();
+ DROP DOMAIN IF EXISTS idid;
+ DROP SERVER IF EXISTS srv_fdw_wrapper;
+ DROP TABLE IF EXISTS tabtype;
+ DROP SCHEMA IF EXISTS testschema;
+ DROP SCHEMA IF EXISTS alterschema;
+ DROP TYPE IF EXISTS public.foo;
+ DROP TYPE IF EXISTS public.footab;
+ DROP DOMAIN IF EXISTS id;
+ DROP FUNCTION IF EXISTS f();
+ DROP FOREIGN DATA WRAPPER IF EXISTS fdw_wrapper;
+}
+
+session "s1"
+
+step "s1_begin" { BEGIN; }
+step "s1_create_function_in_schema" { CREATE FUNCTION testschema.foo() RETURNS int AS 'select 1' LANGUAGE sql; }
+step "s1_create_function_with_argtype" { CREATE FUNCTION fooargtype(num foo) RETURNS int AS 'select 1' LANGUAGE sql; }
+step "s1_create_function_with_rettype" { CREATE FUNCTION footrettype() RETURNS id LANGUAGE sql RETURN 1; }
+step "s1_create_function_with_function" { CREATE FUNCTION foofunc() RETURNS int LANGUAGE SQL RETURN f() + 1; }
+step "s1_alter_function_schema" { ALTER FUNCTION public.falter() SET SCHEMA alterschema; }
+step "s1_create_domain_with_domain" { CREATE DOMAIN idid as id; }
+step "s1_create_table_with_type" { CREATE TABLE tabtype(a footab); }
+step "s1_create_server_with_fdw_wrapper" { CREATE SERVER srv_fdw_wrapper FOREIGN DATA WRAPPER fdw_wrapper; }
+step "s1_commit" { COMMIT; }
+
+session "s2"
+
+step "s2_begin" { BEGIN; }
+step "s2_drop_schema" { DROP SCHEMA testschema; }
+step "s2_drop_alterschema" { DROP SCHEMA alterschema; }
+step "s2_drop_foo_type" { DROP TYPE public.foo; }
+step "s2_drop_foo_rettype" { DROP DOMAIN id; }
+step "s2_drop_footab_type" { DROP TYPE public.footab; }
+step "s2_drop_function_f" { DROP FUNCTION f(); }
+step "s2_drop_domain_id" { DROP DOMAIN id; }
+step "s2_drop_fdw_wrapper" { DROP FOREIGN DATA WRAPPER fdw_wrapper RESTRICT; }
+step "s2_commit" { COMMIT; }
+
+# function - schema
+permutation "s1_begin" "s1_create_function_in_schema" "s2_drop_schema" "s1_commit"
+permutation "s2_begin" "s2_drop_schema" "s1_create_function_in_schema" "s2_commit"
+
+# alter function - schema
+permutation "s1_begin" "s1_alter_function_schema" "s2_drop_alterschema" "s1_commit"
+permutation "s2_begin" "s2_drop_alterschema" "s1_alter_function_schema" "s2_commit"
+
+# function - argtype
+permutation "s1_begin" "s1_create_function_with_argtype" "s2_drop_foo_type" "s1_commit"
+permutation "s2_begin" "s2_drop_foo_type" "s1_create_function_with_argtype" "s2_commit"
+
+# function - rettype
+permutation "s1_begin" "s1_create_function_with_rettype" "s2_drop_foo_rettype" "s1_commit"
+permutation "s2_begin" "s2_drop_foo_rettype" "s1_create_function_with_rettype" "s2_commit"
+
+# function - function
+permutation "s1_begin" "s1_create_function_with_function" "s2_drop_function_f" "s1_commit"
+permutation "s2_begin" "s2_drop_function_f" "s1_create_function_with_function" "s2_commit"
+
+# domain - domain
+permutation "s1_begin" "s1_create_domain_with_domain" "s2_drop_domain_id" "s1_commit"
+permutation "s2_begin" "s2_drop_domain_id" "s1_create_domain_with_domain" "s2_commit"
+
+# table - type
+permutation "s1_begin" "s1_create_table_with_type" "s2_drop_footab_type" "s1_commit"
+permutation "s2_begin" "s2_drop_footab_type" "s1_create_table_with_type" "s2_commit"
+
+# server - foreign data wrapper
+permutation "s1_begin" "s1_create_server_with_fdw_wrapper" "s2_drop_fdw_wrapper" "s1_commit"
+permutation "s2_begin" "s2_drop_fdw_wrapper" "s1_create_server_with_fdw_wrapper" "s2_commit"
diff --git a/src/test/modules/test_oat_hooks/expected/alter_table.out b/src/test/modules/test_oat_hooks/expected/alter_table.out
index 8cbacca2c9..df8d276dfc 100644
--- a/src/test/modules/test_oat_hooks/expected/alter_table.out
+++ b/src/test/modules/test_oat_hooks/expected/alter_table.out
@@ -37,6 +37,8 @@ NOTICE: in object access: superuser attempting create (subId=0x0) [internal]
NOTICE: in object access: superuser finished create (subId=0x0) [internal]
NOTICE: in object access: superuser attempting create (subId=0x0) [internal]
NOTICE: in object access: superuser finished create (subId=0x0) [internal]
+NOTICE: in object access: superuser attempting namespace search (subId=0x0) [no report on violation, allowed]
+NOTICE: in object access: superuser finished namespace search (subId=0x0) [no report on violation, allowed]
NOTICE: in process utility: superuser finished CREATE TABLE
CREATE RULE test_oat_notify AS
ON UPDATE TO test_oat_schema.test_oat_tab
@@ -62,8 +64,6 @@ BEGIN
END IF;
END; $$;
NOTICE: in process utility: superuser attempting CREATE FUNCTION
-NOTICE: in object access: superuser attempting namespace search (subId=0x0) [no report on violation, allowed]
-NOTICE: in object access: superuser finished namespace search (subId=0x0) [no report on violation, allowed]
NOTICE: in object access: superuser attempting create (subId=0x0) [explicit]
NOTICE: in object access: superuser finished create (subId=0x0) [explicit]
NOTICE: in process utility: superuser finished CREATE FUNCTION
diff --git a/src/test/modules/test_oat_hooks/expected/test_oat_hooks.out b/src/test/modules/test_oat_hooks/expected/test_oat_hooks.out
index effdc49145..da6d931994 100644
--- a/src/test/modules/test_oat_hooks/expected/test_oat_hooks.out
+++ b/src/test/modules/test_oat_hooks/expected/test_oat_hooks.out
@@ -86,6 +86,8 @@ NOTICE: in object access: superuser attempting create (subId=0x0) [internal]
NOTICE: in object access: superuser finished create (subId=0x0) [internal]
NOTICE: in object access: superuser attempting create (subId=0x0) [internal]
NOTICE: in object access: superuser finished create (subId=0x0) [internal]
+NOTICE: in object access: superuser attempting namespace search (subId=0x0) [no report on violation, allowed]
+NOTICE: in object access: superuser finished namespace search (subId=0x0) [no report on violation, allowed]
NOTICE: in process utility: superuser finished CREATE TABLE
CREATE INDEX regress_test_table_t_idx ON regress_test_table (t);
NOTICE: in process utility: superuser attempting CREATE INDEX
diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index 12852aa612..552edf57b9 100644
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -2852,11 +2852,12 @@ begin;
alter table alterlock2
add constraint alterlock2nv foreign key (f1) references alterlock (f1) NOT VALID;
select * from my_locks order by 1;
- relname | max_lockmode
-------------+-----------------------
- alterlock | ShareRowExclusiveLock
- alterlock2 | ShareRowExclusiveLock
-(2 rows)
+ relname | max_lockmode
+----------------+-----------------------
+ alterlock | ShareRowExclusiveLock
+ alterlock2 | ShareRowExclusiveLock
+ alterlock_pkey | AccessShareLock
+(3 rows)
commit;
begin;
--
2.34.1
--psqiKZG/Rh65s32s--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v1] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 2 +
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 160 insertions(+), 1 deletion(-)
26.9% doc/src/sgml/
29.1% src/backend/utils/activity/
12.3% src/backend/utils/adt/
9.7% src/include/catalog/
4.0% src/include/utils/
9.2% src/test/regress/expected/
7.3% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index fa78031ccbb..ef89683164f 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..7cec0c83071 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,13 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static int pgStatBackendXactCommit = 0;
+static int pgStatBackendXactRollback = 0;
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +266,33 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += pgStatBackendXactCommit;
+ shbackendent->stats.xact_rollback += pgStatBackendXactRollback;
+
+ pgStatBackendXactCommit = pgStatBackendXactRollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +317,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +336,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +441,22 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ pgStatBackendXactCommit++;
+ else
+ pgStatBackendXactRollback++;
+
+ backend_has_xactstats = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..4c9f6b0dcec 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--ZnbSmJtA6EgjuGCe--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v2] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 166 insertions(+), 1 deletion(-)
26.1% doc/src/sgml/
29.1% src/backend/utils/activity/
11.9% src/backend/utils/adt/
9.4% src/include/catalog/
3.9% src/include/utils/
3.3% src/include/
8.9% src/test/regress/expected/
7.1% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 3f4a27a736e..77b41e02b82 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..12ae9a8d321 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,23 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..d3491faaff2 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Xact statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--SywurcztURg2uk+W--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v3 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. A new function is called in AtEOXact_PgStat() to increment those
two new counters.
---
src/backend/utils/activity/pgstat_backend.c | 57 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
4 files changed, 69 insertions(+), 1 deletion(-)
78.9% src/backend/utils/activity/
11.2% src/include/utils/
9.8% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..bf164854c4b 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,20 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /* Count transaction commit or abort */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..9efc0e10ebf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v4 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..47ce61e5093 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -36,7 +36,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index b31f20d41bc..400a8c5d734 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -342,6 +342,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..0fdbaf79780 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -801,6 +809,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..b97184c6539 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,7 +616,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v5 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 7727fed3bda..42bfb9cd38f 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -37,7 +37,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -48,6 +48,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -261,6 +266,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -285,6 +318,10 @@ pgstat_flush_backend(bool nowait, uint32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -300,6 +337,9 @@ pgstat_flush_backend(bool nowait, uint32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index 933dcb5cae5..218ff5e653c 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -352,6 +352,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 8e3549c3752..5d73c4dfbcf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -523,6 +523,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -535,6 +537,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -844,6 +852,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index eed4c6b359c..8077c65e938 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -707,7 +707,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, uint32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v5 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 7727fed3bda..42bfb9cd38f 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -37,7 +37,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -48,6 +48,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -261,6 +266,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -285,6 +318,10 @@ pgstat_flush_backend(bool nowait, uint32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -300,6 +337,9 @@ pgstat_flush_backend(bool nowait, uint32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index 933dcb5cae5..218ff5e653c 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -352,6 +352,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 8e3549c3752..5d73c4dfbcf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -523,6 +523,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -535,6 +537,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -844,6 +852,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index eed4c6b359c..8077c65e938 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -707,7 +707,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, uint32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v5 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 7727fed3bda..42bfb9cd38f 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -37,7 +37,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -48,6 +48,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -261,6 +266,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -285,6 +318,10 @@ pgstat_flush_backend(bool nowait, uint32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -300,6 +337,9 @@ pgstat_flush_backend(bool nowait, uint32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index 933dcb5cae5..218ff5e653c 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -352,6 +352,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 8e3549c3752..5d73c4dfbcf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -523,6 +523,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -535,6 +537,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -844,6 +852,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index eed4c6b359c..8077c65e938 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -707,7 +707,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, uint32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v4 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..47ce61e5093 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -36,7 +36,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index b31f20d41bc..400a8c5d734 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -342,6 +342,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..0fdbaf79780 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -801,6 +809,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..b97184c6539 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,7 +616,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v5 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 7727fed3bda..42bfb9cd38f 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -37,7 +37,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -48,6 +48,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -261,6 +266,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -285,6 +318,10 @@ pgstat_flush_backend(bool nowait, uint32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -300,6 +337,9 @@ pgstat_flush_backend(bool nowait, uint32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index 933dcb5cae5..218ff5e653c 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -352,6 +352,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 8e3549c3752..5d73c4dfbcf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -523,6 +523,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -535,6 +537,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -844,6 +852,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index eed4c6b359c..8077c65e938 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -707,7 +707,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, uint32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v1] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 2 +
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 160 insertions(+), 1 deletion(-)
26.9% doc/src/sgml/
29.1% src/backend/utils/activity/
12.3% src/backend/utils/adt/
9.7% src/include/catalog/
4.0% src/include/utils/
9.2% src/test/regress/expected/
7.3% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index fa78031ccbb..ef89683164f 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..7cec0c83071 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,13 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static int pgStatBackendXactCommit = 0;
+static int pgStatBackendXactRollback = 0;
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +266,33 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += pgStatBackendXactCommit;
+ shbackendent->stats.xact_rollback += pgStatBackendXactRollback;
+
+ pgStatBackendXactCommit = pgStatBackendXactRollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +317,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +336,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +441,22 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ pgStatBackendXactCommit++;
+ else
+ pgStatBackendXactRollback++;
+
+ backend_has_xactstats = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..4c9f6b0dcec 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--ZnbSmJtA6EgjuGCe--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v2] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 166 insertions(+), 1 deletion(-)
26.1% doc/src/sgml/
29.1% src/backend/utils/activity/
11.9% src/backend/utils/adt/
9.4% src/include/catalog/
3.9% src/include/utils/
3.3% src/include/
8.9% src/test/regress/expected/
7.1% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 3f4a27a736e..77b41e02b82 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..12ae9a8d321 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,23 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..d3491faaff2 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Xact statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--SywurcztURg2uk+W--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v3 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. A new function is called in AtEOXact_PgStat() to increment those
two new counters.
---
src/backend/utils/activity/pgstat_backend.c | 57 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
4 files changed, 69 insertions(+), 1 deletion(-)
78.9% src/backend/utils/activity/
11.2% src/include/utils/
9.8% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..bf164854c4b 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,20 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /* Count transaction commit or abort */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..9efc0e10ebf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v4 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..47ce61e5093 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -36,7 +36,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index b31f20d41bc..400a8c5d734 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -342,6 +342,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..0fdbaf79780 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -801,6 +809,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..b97184c6539 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,7 +616,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v4 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..47ce61e5093 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -36,7 +36,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index b31f20d41bc..400a8c5d734 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -342,6 +342,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..0fdbaf79780 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -801,6 +809,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..b97184c6539 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,7 +616,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v5 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 7727fed3bda..42bfb9cd38f 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -37,7 +37,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -48,6 +48,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -261,6 +266,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -285,6 +318,10 @@ pgstat_flush_backend(bool nowait, uint32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -300,6 +337,9 @@ pgstat_flush_backend(bool nowait, uint32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index 933dcb5cae5..218ff5e653c 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -352,6 +352,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 8e3549c3752..5d73c4dfbcf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -523,6 +523,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -535,6 +537,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -844,6 +852,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index eed4c6b359c..8077c65e938 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -707,7 +707,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, uint32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v1] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 2 +
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 160 insertions(+), 1 deletion(-)
26.9% doc/src/sgml/
29.1% src/backend/utils/activity/
12.3% src/backend/utils/adt/
9.7% src/include/catalog/
4.0% src/include/utils/
9.2% src/test/regress/expected/
7.3% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index fa78031ccbb..ef89683164f 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..7cec0c83071 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,13 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static int pgStatBackendXactCommit = 0;
+static int pgStatBackendXactRollback = 0;
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +266,33 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += pgStatBackendXactCommit;
+ shbackendent->stats.xact_rollback += pgStatBackendXactRollback;
+
+ pgStatBackendXactCommit = pgStatBackendXactRollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +317,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +336,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +441,22 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ pgStatBackendXactCommit++;
+ else
+ pgStatBackendXactRollback++;
+
+ backend_has_xactstats = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..4c9f6b0dcec 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--ZnbSmJtA6EgjuGCe--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v2] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 166 insertions(+), 1 deletion(-)
26.1% doc/src/sgml/
29.1% src/backend/utils/activity/
11.9% src/backend/utils/adt/
9.4% src/include/catalog/
3.9% src/include/utils/
3.3% src/include/
8.9% src/test/regress/expected/
7.1% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 3f4a27a736e..77b41e02b82 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..12ae9a8d321 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,23 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..d3491faaff2 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Xact statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--SywurcztURg2uk+W--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v3 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. A new function is called in AtEOXact_PgStat() to increment those
two new counters.
---
src/backend/utils/activity/pgstat_backend.c | 57 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
4 files changed, 69 insertions(+), 1 deletion(-)
78.9% src/backend/utils/activity/
11.2% src/include/utils/
9.8% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..bf164854c4b 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,20 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /* Count transaction commit or abort */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..9efc0e10ebf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v4 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..47ce61e5093 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -36,7 +36,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index b31f20d41bc..400a8c5d734 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -342,6 +342,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..0fdbaf79780 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -801,6 +809,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..b97184c6539 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,7 +616,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v5 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 7727fed3bda..42bfb9cd38f 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -37,7 +37,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -48,6 +48,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -261,6 +266,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -285,6 +318,10 @@ pgstat_flush_backend(bool nowait, uint32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -300,6 +337,9 @@ pgstat_flush_backend(bool nowait, uint32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index 933dcb5cae5..218ff5e653c 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -352,6 +352,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 8e3549c3752..5d73c4dfbcf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -523,6 +523,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -535,6 +537,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -844,6 +852,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index eed4c6b359c..8077c65e938 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -707,7 +707,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, uint32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v1] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 2 +
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 160 insertions(+), 1 deletion(-)
26.9% doc/src/sgml/
29.1% src/backend/utils/activity/
12.3% src/backend/utils/adt/
9.7% src/include/catalog/
4.0% src/include/utils/
9.2% src/test/regress/expected/
7.3% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index fa78031ccbb..ef89683164f 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..7cec0c83071 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,13 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static int pgStatBackendXactCommit = 0;
+static int pgStatBackendXactRollback = 0;
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +266,33 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += pgStatBackendXactCommit;
+ shbackendent->stats.xact_rollback += pgStatBackendXactRollback;
+
+ pgStatBackendXactCommit = pgStatBackendXactRollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +317,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +336,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +441,22 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ pgStatBackendXactCommit++;
+ else
+ pgStatBackendXactRollback++;
+
+ backend_has_xactstats = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..4c9f6b0dcec 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--ZnbSmJtA6EgjuGCe--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v2] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 166 insertions(+), 1 deletion(-)
26.1% doc/src/sgml/
29.1% src/backend/utils/activity/
11.9% src/backend/utils/adt/
9.4% src/include/catalog/
3.9% src/include/utils/
3.3% src/include/
8.9% src/test/regress/expected/
7.1% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 3f4a27a736e..77b41e02b82 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..12ae9a8d321 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,23 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..d3491faaff2 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Xact statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--SywurcztURg2uk+W--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v3 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. A new function is called in AtEOXact_PgStat() to increment those
two new counters.
---
src/backend/utils/activity/pgstat_backend.c | 57 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
4 files changed, 69 insertions(+), 1 deletion(-)
78.9% src/backend/utils/activity/
11.2% src/include/utils/
9.8% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..bf164854c4b 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,20 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /* Count transaction commit or abort */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..9efc0e10ebf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v4 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..47ce61e5093 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -36,7 +36,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index b31f20d41bc..400a8c5d734 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -342,6 +342,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..0fdbaf79780 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -801,6 +809,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..b97184c6539 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,7 +616,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v5 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 7727fed3bda..42bfb9cd38f 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -37,7 +37,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -48,6 +48,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -261,6 +266,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -285,6 +318,10 @@ pgstat_flush_backend(bool nowait, uint32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -300,6 +337,9 @@ pgstat_flush_backend(bool nowait, uint32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index 933dcb5cae5..218ff5e653c 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -352,6 +352,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 8e3549c3752..5d73c4dfbcf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -523,6 +523,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -535,6 +537,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -844,6 +852,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index eed4c6b359c..8077c65e938 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -707,7 +707,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, uint32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v1] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 2 +
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 160 insertions(+), 1 deletion(-)
26.9% doc/src/sgml/
29.1% src/backend/utils/activity/
12.3% src/backend/utils/adt/
9.7% src/include/catalog/
4.0% src/include/utils/
9.2% src/test/regress/expected/
7.3% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index fa78031ccbb..ef89683164f 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..7cec0c83071 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,13 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static int pgStatBackendXactCommit = 0;
+static int pgStatBackendXactRollback = 0;
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +266,33 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += pgStatBackendXactCommit;
+ shbackendent->stats.xact_rollback += pgStatBackendXactRollback;
+
+ pgStatBackendXactCommit = pgStatBackendXactRollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +317,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +336,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +441,22 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ pgStatBackendXactCommit++;
+ else
+ pgStatBackendXactRollback++;
+
+ backend_has_xactstats = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..4c9f6b0dcec 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--ZnbSmJtA6EgjuGCe--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v2] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 166 insertions(+), 1 deletion(-)
26.1% doc/src/sgml/
29.1% src/backend/utils/activity/
11.9% src/backend/utils/adt/
9.4% src/include/catalog/
3.9% src/include/utils/
3.3% src/include/
8.9% src/test/regress/expected/
7.1% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 3f4a27a736e..77b41e02b82 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..12ae9a8d321 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,23 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..d3491faaff2 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Xact statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--SywurcztURg2uk+W--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v3 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. A new function is called in AtEOXact_PgStat() to increment those
two new counters.
---
src/backend/utils/activity/pgstat_backend.c | 57 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
4 files changed, 69 insertions(+), 1 deletion(-)
78.9% src/backend/utils/activity/
11.2% src/include/utils/
9.8% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..bf164854c4b 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,20 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /* Count transaction commit or abort */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..9efc0e10ebf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v4 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..47ce61e5093 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -36,7 +36,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index b31f20d41bc..400a8c5d734 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -342,6 +342,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..0fdbaf79780 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -801,6 +809,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..b97184c6539 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,7 +616,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v5 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 7727fed3bda..42bfb9cd38f 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -37,7 +37,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -48,6 +48,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -261,6 +266,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -285,6 +318,10 @@ pgstat_flush_backend(bool nowait, uint32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -300,6 +337,9 @@ pgstat_flush_backend(bool nowait, uint32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index 933dcb5cae5..218ff5e653c 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -352,6 +352,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 8e3549c3752..5d73c4dfbcf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -523,6 +523,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -535,6 +537,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -844,6 +852,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index eed4c6b359c..8077c65e938 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -707,7 +707,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, uint32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v1] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 2 +
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 160 insertions(+), 1 deletion(-)
26.9% doc/src/sgml/
29.1% src/backend/utils/activity/
12.3% src/backend/utils/adt/
9.7% src/include/catalog/
4.0% src/include/utils/
9.2% src/test/regress/expected/
7.3% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index fa78031ccbb..ef89683164f 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..7cec0c83071 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,13 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static int pgStatBackendXactCommit = 0;
+static int pgStatBackendXactRollback = 0;
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +266,33 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += pgStatBackendXactCommit;
+ shbackendent->stats.xact_rollback += pgStatBackendXactRollback;
+
+ pgStatBackendXactCommit = pgStatBackendXactRollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +317,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +336,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +441,22 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ pgStatBackendXactCommit++;
+ else
+ pgStatBackendXactRollback++;
+
+ backend_has_xactstats = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..4c9f6b0dcec 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--ZnbSmJtA6EgjuGCe--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v2] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 166 insertions(+), 1 deletion(-)
26.1% doc/src/sgml/
29.1% src/backend/utils/activity/
11.9% src/backend/utils/adt/
9.4% src/include/catalog/
3.9% src/include/utils/
3.3% src/include/
8.9% src/test/regress/expected/
7.1% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 3f4a27a736e..77b41e02b82 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..12ae9a8d321 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,23 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..d3491faaff2 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Xact statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--SywurcztURg2uk+W--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v3 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. A new function is called in AtEOXact_PgStat() to increment those
two new counters.
---
src/backend/utils/activity/pgstat_backend.c | 57 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
4 files changed, 69 insertions(+), 1 deletion(-)
78.9% src/backend/utils/activity/
11.2% src/include/utils/
9.8% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..bf164854c4b 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,20 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /* Count transaction commit or abort */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..9efc0e10ebf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v1] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 2 +
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 160 insertions(+), 1 deletion(-)
26.9% doc/src/sgml/
29.1% src/backend/utils/activity/
12.3% src/backend/utils/adt/
9.7% src/include/catalog/
4.0% src/include/utils/
9.2% src/test/regress/expected/
7.3% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index fa78031ccbb..ef89683164f 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..7cec0c83071 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,13 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static int pgStatBackendXactCommit = 0;
+static int pgStatBackendXactRollback = 0;
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +266,33 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += pgStatBackendXactCommit;
+ shbackendent->stats.xact_rollback += pgStatBackendXactRollback;
+
+ pgStatBackendXactCommit = pgStatBackendXactRollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +317,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +336,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +441,22 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ pgStatBackendXactCommit++;
+ else
+ pgStatBackendXactRollback++;
+
+ backend_has_xactstats = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..4c9f6b0dcec 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--ZnbSmJtA6EgjuGCe--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v2] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 166 insertions(+), 1 deletion(-)
26.1% doc/src/sgml/
29.1% src/backend/utils/activity/
11.9% src/backend/utils/adt/
9.4% src/include/catalog/
3.9% src/include/utils/
3.3% src/include/
8.9% src/test/regress/expected/
7.1% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 3f4a27a736e..77b41e02b82 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..12ae9a8d321 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,23 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..d3491faaff2 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Xact statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--SywurcztURg2uk+W--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v3 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. A new function is called in AtEOXact_PgStat() to increment those
two new counters.
---
src/backend/utils/activity/pgstat_backend.c | 57 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
4 files changed, 69 insertions(+), 1 deletion(-)
78.9% src/backend/utils/activity/
11.2% src/include/utils/
9.8% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..bf164854c4b 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,20 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /* Count transaction commit or abort */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..9efc0e10ebf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v5 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 7727fed3bda..42bfb9cd38f 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -37,7 +37,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -48,6 +48,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -261,6 +266,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -285,6 +318,10 @@ pgstat_flush_backend(bool nowait, uint32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -300,6 +337,9 @@ pgstat_flush_backend(bool nowait, uint32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index 933dcb5cae5..218ff5e653c 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -352,6 +352,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 8e3549c3752..5d73c4dfbcf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -523,6 +523,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -535,6 +537,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -844,6 +852,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index eed4c6b359c..8077c65e938 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -707,7 +707,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, uint32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v1] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 2 +
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 160 insertions(+), 1 deletion(-)
26.9% doc/src/sgml/
29.1% src/backend/utils/activity/
12.3% src/backend/utils/adt/
9.7% src/include/catalog/
4.0% src/include/utils/
9.2% src/test/regress/expected/
7.3% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index fa78031ccbb..ef89683164f 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..7cec0c83071 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,13 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static int pgStatBackendXactCommit = 0;
+static int pgStatBackendXactRollback = 0;
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +266,33 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += pgStatBackendXactCommit;
+ shbackendent->stats.xact_rollback += pgStatBackendXactRollback;
+
+ pgStatBackendXactCommit = pgStatBackendXactRollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +317,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +336,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +441,22 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ pgStatBackendXactCommit++;
+ else
+ pgStatBackendXactRollback++;
+
+ backend_has_xactstats = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..4c9f6b0dcec 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--ZnbSmJtA6EgjuGCe--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v2] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 166 insertions(+), 1 deletion(-)
26.1% doc/src/sgml/
29.1% src/backend/utils/activity/
11.9% src/backend/utils/adt/
9.4% src/include/catalog/
3.9% src/include/utils/
3.3% src/include/
8.9% src/test/regress/expected/
7.1% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 3f4a27a736e..77b41e02b82 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..12ae9a8d321 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,23 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..d3491faaff2 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Xact statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--SywurcztURg2uk+W--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v3 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. A new function is called in AtEOXact_PgStat() to increment those
two new counters.
---
src/backend/utils/activity/pgstat_backend.c | 57 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
4 files changed, 69 insertions(+), 1 deletion(-)
78.9% src/backend/utils/activity/
11.2% src/include/utils/
9.8% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..bf164854c4b 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,20 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /* Count transaction commit or abort */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..9efc0e10ebf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v4 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..47ce61e5093 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -36,7 +36,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index b31f20d41bc..400a8c5d734 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -342,6 +342,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..0fdbaf79780 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -801,6 +809,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..b97184c6539 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,7 +616,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v5 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 7727fed3bda..42bfb9cd38f 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -37,7 +37,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -48,6 +48,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -261,6 +266,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -285,6 +318,10 @@ pgstat_flush_backend(bool nowait, uint32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -300,6 +337,9 @@ pgstat_flush_backend(bool nowait, uint32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index 933dcb5cae5..218ff5e653c 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -352,6 +352,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 8e3549c3752..5d73c4dfbcf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -523,6 +523,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -535,6 +537,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -844,6 +852,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index eed4c6b359c..8077c65e938 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -707,7 +707,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, uint32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v1] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 2 +
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 160 insertions(+), 1 deletion(-)
26.9% doc/src/sgml/
29.1% src/backend/utils/activity/
12.3% src/backend/utils/adt/
9.7% src/include/catalog/
4.0% src/include/utils/
9.2% src/test/regress/expected/
7.3% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index fa78031ccbb..ef89683164f 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..7cec0c83071 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,13 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static int pgStatBackendXactCommit = 0;
+static int pgStatBackendXactRollback = 0;
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +266,33 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += pgStatBackendXactCommit;
+ shbackendent->stats.xact_rollback += pgStatBackendXactRollback;
+
+ pgStatBackendXactCommit = pgStatBackendXactRollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +317,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +336,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +441,22 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ pgStatBackendXactCommit++;
+ else
+ pgStatBackendXactRollback++;
+
+ backend_has_xactstats = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..4c9f6b0dcec 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--ZnbSmJtA6EgjuGCe--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v2] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 166 insertions(+), 1 deletion(-)
26.1% doc/src/sgml/
29.1% src/backend/utils/activity/
11.9% src/backend/utils/adt/
9.4% src/include/catalog/
3.9% src/include/utils/
3.3% src/include/
8.9% src/test/regress/expected/
7.1% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 3f4a27a736e..77b41e02b82 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..12ae9a8d321 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,23 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..d3491faaff2 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Xact statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--SywurcztURg2uk+W--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v3 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. A new function is called in AtEOXact_PgStat() to increment those
two new counters.
---
src/backend/utils/activity/pgstat_backend.c | 57 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
4 files changed, 69 insertions(+), 1 deletion(-)
78.9% src/backend/utils/activity/
11.2% src/include/utils/
9.8% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..bf164854c4b 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,20 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /* Count transaction commit or abort */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..9efc0e10ebf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v4 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..47ce61e5093 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -36,7 +36,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index b31f20d41bc..400a8c5d734 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -342,6 +342,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..0fdbaf79780 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -801,6 +809,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..b97184c6539 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,7 +616,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v5 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 7727fed3bda..42bfb9cd38f 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -37,7 +37,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -48,6 +48,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -261,6 +266,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -285,6 +318,10 @@ pgstat_flush_backend(bool nowait, uint32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -300,6 +337,9 @@ pgstat_flush_backend(bool nowait, uint32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index 933dcb5cae5..218ff5e653c 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -352,6 +352,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 8e3549c3752..5d73c4dfbcf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -523,6 +523,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -535,6 +537,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -844,6 +852,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index eed4c6b359c..8077c65e938 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -707,7 +707,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, uint32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v1] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 2 +
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 160 insertions(+), 1 deletion(-)
26.9% doc/src/sgml/
29.1% src/backend/utils/activity/
12.3% src/backend/utils/adt/
9.7% src/include/catalog/
4.0% src/include/utils/
9.2% src/test/regress/expected/
7.3% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index fa78031ccbb..ef89683164f 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..7cec0c83071 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,13 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static int pgStatBackendXactCommit = 0;
+static int pgStatBackendXactRollback = 0;
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +266,33 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += pgStatBackendXactCommit;
+ shbackendent->stats.xact_rollback += pgStatBackendXactRollback;
+
+ pgStatBackendXactCommit = pgStatBackendXactRollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +317,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +336,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +441,22 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ pgStatBackendXactCommit++;
+ else
+ pgStatBackendXactRollback++;
+
+ backend_has_xactstats = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..4c9f6b0dcec 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--ZnbSmJtA6EgjuGCe--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v2] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 166 insertions(+), 1 deletion(-)
26.1% doc/src/sgml/
29.1% src/backend/utils/activity/
11.9% src/backend/utils/adt/
9.4% src/include/catalog/
3.9% src/include/utils/
3.3% src/include/
8.9% src/test/regress/expected/
7.1% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 3f4a27a736e..77b41e02b82 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..12ae9a8d321 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,23 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..d3491faaff2 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Xact statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--SywurcztURg2uk+W--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v3 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. A new function is called in AtEOXact_PgStat() to increment those
two new counters.
---
src/backend/utils/activity/pgstat_backend.c | 57 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
4 files changed, 69 insertions(+), 1 deletion(-)
78.9% src/backend/utils/activity/
11.2% src/include/utils/
9.8% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..bf164854c4b 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,20 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /* Count transaction commit or abort */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..9efc0e10ebf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v4 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..47ce61e5093 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -36,7 +36,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index b31f20d41bc..400a8c5d734 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -342,6 +342,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..0fdbaf79780 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -801,6 +809,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..b97184c6539 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,7 +616,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v5 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 7727fed3bda..42bfb9cd38f 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -37,7 +37,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -48,6 +48,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -261,6 +266,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -285,6 +318,10 @@ pgstat_flush_backend(bool nowait, uint32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -300,6 +337,9 @@ pgstat_flush_backend(bool nowait, uint32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index 933dcb5cae5..218ff5e653c 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -352,6 +352,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 8e3549c3752..5d73c4dfbcf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -523,6 +523,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -535,6 +537,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -844,6 +852,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index eed4c6b359c..8077c65e938 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -707,7 +707,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, uint32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v1] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 2 +
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 160 insertions(+), 1 deletion(-)
26.9% doc/src/sgml/
29.1% src/backend/utils/activity/
12.3% src/backend/utils/adt/
9.7% src/include/catalog/
4.0% src/include/utils/
9.2% src/test/regress/expected/
7.3% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index fa78031ccbb..ef89683164f 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..7cec0c83071 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,13 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static int pgStatBackendXactCommit = 0;
+static int pgStatBackendXactRollback = 0;
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +266,33 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += pgStatBackendXactCommit;
+ shbackendent->stats.xact_rollback += pgStatBackendXactRollback;
+
+ pgStatBackendXactCommit = pgStatBackendXactRollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +317,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +336,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +441,22 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ pgStatBackendXactCommit++;
+ else
+ pgStatBackendXactRollback++;
+
+ backend_has_xactstats = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..4c9f6b0dcec 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--ZnbSmJtA6EgjuGCe--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v2] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 166 insertions(+), 1 deletion(-)
26.1% doc/src/sgml/
29.1% src/backend/utils/activity/
11.9% src/backend/utils/adt/
9.4% src/include/catalog/
3.9% src/include/utils/
3.3% src/include/
8.9% src/test/regress/expected/
7.1% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 3f4a27a736e..77b41e02b82 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..12ae9a8d321 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,23 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..d3491faaff2 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Xact statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--SywurcztURg2uk+W--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v3 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. A new function is called in AtEOXact_PgStat() to increment those
two new counters.
---
src/backend/utils/activity/pgstat_backend.c | 57 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
4 files changed, 69 insertions(+), 1 deletion(-)
78.9% src/backend/utils/activity/
11.2% src/include/utils/
9.8% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..bf164854c4b 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,20 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /* Count transaction commit or abort */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..9efc0e10ebf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v4 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..47ce61e5093 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -36,7 +36,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index b31f20d41bc..400a8c5d734 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -342,6 +342,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..0fdbaf79780 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -801,6 +809,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..b97184c6539 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,7 +616,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v1] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 2 +
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 160 insertions(+), 1 deletion(-)
26.9% doc/src/sgml/
29.1% src/backend/utils/activity/
12.3% src/backend/utils/adt/
9.7% src/include/catalog/
4.0% src/include/utils/
9.2% src/test/regress/expected/
7.3% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index fa78031ccbb..ef89683164f 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..7cec0c83071 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,13 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static int pgStatBackendXactCommit = 0;
+static int pgStatBackendXactRollback = 0;
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +266,33 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += pgStatBackendXactCommit;
+ shbackendent->stats.xact_rollback += pgStatBackendXactRollback;
+
+ pgStatBackendXactCommit = pgStatBackendXactRollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +317,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +336,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +441,22 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ pgStatBackendXactCommit++;
+ else
+ pgStatBackendXactRollback++;
+
+ backend_has_xactstats = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..4c9f6b0dcec 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--ZnbSmJtA6EgjuGCe--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v2] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
This commit adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
It relies on the existing per backend statistics that has been added in
9aea73fc61d.
---
doc/src/sgml/monitoring.sgml | 36 +++++++++++++
src/backend/utils/activity/pgstat_backend.c | 60 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/backend/utils/adt/pgstatfuncs.c | 22 ++++++++
src/include/catalog/pg_proc.dat | 9 ++++
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
src/test/regress/expected/stats.out | 17 ++++++
src/test/regress/sql/stats.sql | 10 ++++
9 files changed, 166 insertions(+), 1 deletion(-)
26.1% doc/src/sgml/
29.1% src/backend/utils/activity/
11.9% src/backend/utils/adt/
9.4% src/include/catalog/
3.9% src/include/utils/
3.3% src/include/
8.9% src/test/regress/expected/
7.1% src/test/regress/sql/
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 3f4a27a736e..77b41e02b82 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4921,6 +4921,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage
</para></entry>
</row>
+ <row>
+ <entry id="pg-stat-get-backend-xact-commit" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_commit</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_commit</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been committed by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry id="pg-stat-get-backend-xact-rollback" role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_stat_get_backend_xact_rollback</primary>
+ </indexterm>
+ <function>pg_stat_get_backend_xact_rollback</function> ( <type>integer</type> )
+ <returnvalue>bigint</returnvalue>
+ </para>
+ <para>
+ Returns the number of transactions that have been rolled back by the backend
+ with the specified process ID.
+ </para>
+ <para>
+ The function does not return statistics for the checkpointer,
+ the background writer, the startup process and the autovacuum launcher.
+ </para></entry>
+ </row>
+
<row>
<entry id="pg-stat-get-backend-wal" role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..12ae9a8d321 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend xact statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * XACT statistics. In this case, avoid unnecessarily modifying the stats
+ * entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some XACT data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,23 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /*
+ * Count transaction commit or abort. (We use counters, not just
+ * bools, in case the reporting message isn't sent right away.)
+ */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c756c2bebaa..6436129f516 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1606,6 +1606,28 @@ pg_stat_get_backend_io(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+#define PG_STAT_GET_BACKENDENTRY_INT64(stat) \
+Datum \
+CppConcat(pg_stat_get_backend_,stat)(PG_FUNCTION_ARGS) \
+{ \
+ int pid; \
+ PgStat_Backend *backend_stats; \
+ \
+ pid = PG_GETARG_INT32(0); \
+ backend_stats = pgstat_fetch_stat_backend_by_pid(pid, NULL);\
+ \
+ if (!backend_stats) \
+ PG_RETURN_NULL(); \
+ else \
+ PG_RETURN_INT64(backend_stats->stat); \
+}
+
+/* pg_stat_get_backend_xact_commit */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_commit)
+
+/* pg_stat_get_backend_xact_rollback */
+PG_STAT_GET_BACKENDENTRY_INT64(xact_rollback)
+
/*
* pg_stat_wal_build_tuple
*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 118d6da1ace..f5085d4e016 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -6010,6 +6010,15 @@
proargnames => '{backend_pid,backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}',
prosrc => 'pg_stat_get_backend_io' },
+{ oid => '8170', descr => 'statistics: backend transactions committed',
+ proname => 'pg_stat_get_backend_xact_commit', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_commit' },
+{ oid => '8916', descr => 'statistics: backend transactions rolled back',
+ proname => 'pg_stat_get_backend_xact_rollback', provolatile => 's',
+ proparallel => 'r', prorettype => 'int8', proargtypes => 'int4',
+ prosrc => 'pg_stat_get_backend_xact_rollback' },
+
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..d3491faaff2 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Xact statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 605f5070376..0d316f94e40 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -135,11 +135,28 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush
+--------------------------
+
+(1 row)
+
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+SELECT :xact_commit_after > :xact_commit_before;
+ ?column?
+----------
+ t
+(1 row)
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 54e72866344..d629140d880 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -58,12 +58,22 @@ INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
+-- in passing, check that backend's commit is incrementing
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_before
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
+SELECT pg_stat_force_next_flush();
+SELECT pg_stat_get_backend_xact_commit AS xact_commit_after
+ FROM pg_stat_get_backend_xact_commit(pg_backend_pid()) \gset
+
+SELECT :xact_commit_after > :xact_commit_before;
+
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
--
2.34.1
--SywurcztURg2uk+W--
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v3 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. A new function is called in AtEOXact_PgStat() to increment those
two new counters.
---
src/backend/utils/activity/pgstat_backend.c | 57 +++++++++++++++++++++
src/backend/utils/activity/pgstat_xact.c | 1 +
src/include/pgstat.h | 8 +++
src/include/utils/pgstat_internal.h | 4 +-
4 files changed, 69 insertions(+), 1 deletion(-)
78.9% src/backend/utils/activity/
11.2% src/include/utils/
9.8% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..bf164854c4b 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+static bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
@@ -400,3 +440,20 @@ pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
{
((PgStatShared_Backend *) header)->stats.stat_reset_timestamp = ts;
}
+
+void
+AtEOXact_PgStat_Backend(bool isCommit, bool parallel)
+{
+ /* Don't count parallel worker transaction stats */
+ if (!parallel)
+ {
+ /* Count transaction commit or abort */
+ if (isCommit)
+ PendingBackendStats.pending_xact_commit++;
+ else
+ PendingBackendStats.pending_xact_rollback++;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+ }
+}
diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c
index bc9864bd8d9..cd1c501c165 100644
--- a/src/backend/utils/activity/pgstat_xact.c
+++ b/src/backend/utils/activity/pgstat_xact.c
@@ -42,6 +42,7 @@ AtEOXact_PgStat(bool isCommit, bool parallel)
PgStat_SubXactStatus *xact_state;
AtEOXact_PgStat_Database(isCommit, parallel);
+ AtEOXact_PgStat_Backend(isCommit, parallel);
/* handle transactional stats information */
xact_state = pgStatXactStack;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..9efc0e10ebf 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..23ea8ffd618 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,12 +616,14 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
+extern void AtEOXact_PgStat_Backend(bool isCommit, bool parallel);
/*
* Functions in pgstat_bgwriter.c
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* [PATCH v4 1/3] Adding per backend commit and rollback counters
@ 2025-08-04 08:14 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 08:14 UTC (permalink / raw)
It relies on the existing per backend statistics that has been added in
9aea73fc61d. The new pending counters are updated when the database ones are
flushed (to reduce the overhead of incrementing new counters).
---
src/backend/utils/activity/pgstat_backend.c | 42 +++++++++++++++++++-
src/backend/utils/activity/pgstat_database.c | 7 ++++
src/include/pgstat.h | 15 +++++++
src/include/utils/pgstat_internal.h | 3 +-
4 files changed, 65 insertions(+), 2 deletions(-)
74.4% src/backend/utils/activity/
7.8% src/include/utils/
17.7% src/include/
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 8714a85e2d9..47ce61e5093 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -36,7 +36,7 @@
* reported within critical sections so we use static memory in order to avoid
* memory allocation.
*/
-static PgStat_BackendPending PendingBackendStats;
+PgStat_BackendPending PendingBackendStats;
static bool backend_has_iostats = false;
/*
@@ -47,6 +47,11 @@ static bool backend_has_iostats = false;
*/
static WalUsage prevBackendWalUsage;
+/*
+ * For backend commit and rollback statistics.
+ */
+bool backend_has_xactstats = false;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -259,6 +264,34 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
prevBackendWalUsage = pgWalUsage;
}
+/*
+ * Flush out locally pending backend transaction statistics. Locking is managed
+ * by the caller.
+ */
+static void
+pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
+{
+ PgStatShared_Backend *shbackendent;
+
+ /*
+ * This function can be called even if nothing at all has happened for
+ * transaction statistics. In this case, avoid unnecessarily modifying
+ * the stats entry.
+ */
+ if (!backend_has_xactstats)
+ return;
+
+ shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats;
+
+ shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
+ shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+
+ PendingBackendStats.pending_xact_commit = 0;
+ PendingBackendStats.pending_xact_rollback = 0;
+
+ backend_has_xactstats = false;
+}
+
/*
* Flush out locally pending backend statistics
*
@@ -283,6 +316,10 @@ pgstat_flush_backend(bool nowait, bits32 flags)
pgstat_backend_wal_have_pending())
has_pending_data = true;
+ /* Some transaction data pending? */
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ has_pending_data = true;
+
if (!has_pending_data)
return false;
@@ -298,6 +335,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
if (flags & PGSTAT_BACKEND_FLUSH_WAL)
pgstat_flush_backend_entry_wal(entry_ref);
+ if (flags & PGSTAT_BACKEND_FLUSH_XACT)
+ pgstat_flush_backend_entry_xact(entry_ref);
+
pgstat_unlock_entry(entry_ref);
return false;
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index b31f20d41bc..400a8c5d734 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -342,6 +342,13 @@ pgstat_update_dbstats(TimestampTz ts)
dbentry->blk_read_time += pgStatBlockReadTime;
dbentry->blk_write_time += pgStatBlockWriteTime;
+ /* Do the same for backend stats */
+ PendingBackendStats.pending_xact_commit += pgStatXactCommit;
+ PendingBackendStats.pending_xact_rollback += pgStatXactRollback;
+
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
+
if (pgstat_should_report_connstat())
{
long secs;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..0fdbaf79780 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -490,6 +490,8 @@ typedef struct PgStat_Backend
TimestampTz stat_reset_timestamp;
PgStat_BktypeIO io_stats;
PgStat_WalCounters wal_counters;
+ PgStat_Counter xact_commit;
+ PgStat_Counter xact_rollback;
} PgStat_Backend;
/* ---------
@@ -502,6 +504,12 @@ typedef struct PgStat_BackendPending
* Backend statistics store the same amount of IO data as PGSTAT_KIND_IO.
*/
PgStat_PendingIO pending_io;
+
+ /*
+ * Transaction statistics pending flush.
+ */
+ PgStat_Counter pending_xact_commit;
+ PgStat_Counter pending_xact_rollback;
} PgStat_BackendPending;
/*
@@ -801,6 +809,13 @@ extern PGDLLIMPORT int pgstat_track_functions;
extern PGDLLIMPORT int pgstat_fetch_consistency;
+/*
+ * Variables in pgstat_backend.c
+ */
+
+extern PGDLLIMPORT PgStat_BackendPending PendingBackendStats;
+extern PGDLLIMPORT bool backend_has_xactstats;
+
/*
* Variables in pgstat_bgwriter.c
*/
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 6cf00008f63..b97184c6539 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -616,7 +616,8 @@ extern void pgstat_archiver_snapshot_cb(void);
/* flags for pgstat_flush_backend() */
#define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
-#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
+#define PGSTAT_BACKEND_FLUSH_XACT (1 << 2) /* Flush xact statistics */
+#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_XACT)
extern bool pgstat_flush_backend(bool nowait, bits32 flags);
extern bool pgstat_backend_flush_cb(bool nowait);
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0002-Adding-XID-generation-count-per-backend.patch"
^ permalink raw reply [nested|flat] 68+ messages in thread
* Adding per backend commit and rollback counters
@ 2025-08-04 14:20 Bertrand Drouvot <[email protected]>
0 siblings, 1 reply; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-04 14:20 UTC (permalink / raw)
To: PostgreSQL Hackers <[email protected]>
Hi hackers,
PFA a patch for $SUBJECT.
Currently we can find xact_commit and xact_rollback in pg_stat_database but we
don't have this information per backend.
This patch adds 2 functions: pg_stat_get_backend_xact_commit() and
pg_stat_get_backend_xact_rollback() to report the number of transactions that
have been committed/rolled back for a given backend PID.
I think having this information per-backend could be useful, for example, to:
- check which application is producing the highest number of commit / rollback
- check if the application's hosts have "uniform" commit/rollback pattern
- check if some application's hosts are doing a lot of rollback (as compared
to the other hosts): that could mean those hosts are not using an up-to-date
application version
This patch is pretty straightforward as it relies on the existing per backend
statistics machinery that has been added in 9aea73fc61d (so that there is not
that much design to discuss).
On a side note, I noticed that when a transaction fails, say this way:
postgres=# insert into bdt2 values(1);
ERROR: relation "bdt2" does not exist
Then the existing pg_stat_get_db_xact_rollback() does not return the rollback
increment (so does pg_stat_database.xact_rollback). Indeed, the flush is done
during the next commit or explicit rollback.
Maybe we could add an extra counter, that tracks the transactions that have not
been explicitly rolled back (xact_error or such) and flush it at the right time.
Looking forward to your feedback,
Regards,
--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
^ permalink raw reply [nested|flat] 68+ messages in thread
* Re: Adding per backend commit and rollback counters
@ 2025-08-07 08:17 Bertrand Drouvot <[email protected]>
parent: Bertrand Drouvot <[email protected]>
0 siblings, 1 reply; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-07 08:17 UTC (permalink / raw)
To: PostgreSQL Hackers <[email protected]>
Hi,
On Mon, Aug 04, 2025 at 02:20:48PM +0000, Bertrand Drouvot wrote:
> This patch is pretty straightforward as it relies on the existing per backend
> statistics machinery that has been added in 9aea73fc61d (so that there is not
> that much design to discuss).
Still, while working on adding more backend stats (more on that later), I
realized that in v1, I missed to use pgstat_report_fixed (recently added in
793928c2d5a): the attached fixes that.
Also, I think it's better to put the new xact pending counters in the existing
PgStat_BackendPending, done that way in the attached.
Regards,
--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
^ permalink raw reply [nested|flat] 68+ messages in thread
* Re: Adding per backend commit and rollback counters
@ 2025-08-10 07:47 Bertrand Drouvot <[email protected]>
parent: Bertrand Drouvot <[email protected]>
0 siblings, 1 reply; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-10 07:47 UTC (permalink / raw)
To: PostgreSQL Hackers <[email protected]>
Hi,
On Thu, Aug 07, 2025 at 08:17:26AM +0000, Bertrand Drouvot wrote:
> Hi,
>
> On Mon, Aug 04, 2025 at 02:20:48PM +0000, Bertrand Drouvot wrote:
> > This patch is pretty straightforward as it relies on the existing per backend
> > statistics machinery that has been added in 9aea73fc61d (so that there is not
> > that much design to discuss).
>
> Still, while working on adding more backend stats (more on that later), I
> realized that in v1, I missed to use pgstat_report_fixed (recently added in
> 793928c2d5a): the attached fixes that.
>
> Also, I think it's better to put the new xact pending counters in the existing
> PgStat_BackendPending, done that way in the attached.
Another metric that could be useful is to track the XIDs generated by backend.
That would help to see if a backend is consuming XIDs at a high rate.
We can not rely on the number of commits or rollbacks as they take into account
the virtual transactions.
So a new counter has been added in 0002 attached. Also, v3 changes the way
the statistics are displayed. I've in mind to add much more statistics per backend
(such a number of seqscans, vacuum count, analyze count..., I'll open a dedicated
thread for those) and I think that a single view to display them all makes
more sense than a lot of individual functions. This view is added in 0003.
To sum up, v3 contains:
0001 -
Adding per backend commit and rollback counters
It relies on the existing per backend statistics that has been added in
9aea73fc61d. A new function is called in AtEOXact_PgStat() to increment those
two new counters.
0002 -
Adding XID generation count per backend
This patch adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
0003 -
Adding the pg_stat_backend view
This view displays one row per server process, showing statistics related to
the current activity of that process. It currently displays the pid, the
number of XIDs generated, the number of commits, the number of rollbacks and the
time at which these statistics were last reset.
It's built on top of a new function (pg_stat_get_backend_statistics()). The idea
is the same as pg_stat_activity and pg_stat_get_activity().
Adding documentation and tests.
Regards,
--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
^ permalink raw reply [nested|flat] 68+ messages in thread
* Re: Adding per backend commit and rollback counters
@ 2025-08-28 16:07 Bertrand Drouvot <[email protected]>
parent: Bertrand Drouvot <[email protected]>
0 siblings, 1 reply; 68+ messages in thread
From: Bertrand Drouvot @ 2025-08-28 16:07 UTC (permalink / raw)
To: PostgreSQL Hackers <[email protected]>
Hi,
On Sun, Aug 10, 2025 at 07:47:09AM +0000, Bertrand Drouvot wrote:
> To sum up, v3 contains:
>
> 0001 -
> Adding per backend commit and rollback counters
> 0002 -
> Adding XID generation count per backend
> 0003 -
> Adding the pg_stat_backend view
Following recent conversations in [1], those changes have been made in v4
attached:
- avoid tracking the commit and rollback counters twice (for databases and for
backends) but increment the backend stats when the database ones are flushed. Same
idea as [2].
- pg_stat_backend is too generic (see [3]), let's use pg_stat_backend_transaction
instead. I deliberately did not use pg_stat_backend_xact to not confuse with the
other "*xact*" functions/views where the meaning is not the same. I'm open to
other naming suggestion though.
[1]: https://www.postgresql.org/message-id/flat/aJrxug4LCg4Hm5Mm%40ip-10-97-1-34.eu-west-3.compute.intern...
[2]: https://www.postgresql.org/message-id/7fhpds4xqk6bnudzmzkqi33pinsxammpljwde5gfkjdygvejrj%40ojkzfr7dx...
[3]: https://www.postgresql.org/message-id/aK8OuVPmmDTc9CFX%40ip-10-97-1-34.eu-west-3.compute.internal
Regards,
--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
^ permalink raw reply [nested|flat] 68+ messages in thread
* Re: Adding per backend commit and rollback counters
@ 2026-03-30 20:19 Kuba Knysiak <[email protected]>
parent: Bertrand Drouvot <[email protected]>
0 siblings, 1 reply; 68+ messages in thread
From: Kuba Knysiak @ 2026-03-30 20:19 UTC (permalink / raw)
To: [email protected]; +Cc: Bertrand Drouvot <[email protected]>
Hello,
after reviewing the patch together with Miłosz, we found the following:
- In pgstatfuncs.c, we call pgstat_fetch_stat_backend_by_pid(beentry->st_procpid, NULL) for each backend row. That path acquires ProcArrayLock via BackendPidGetProc(), so this repeats lock acquisition for every row. We could simplify this and avoid taking the lock altogether by fetching directly with pgstat_fetch_stat_backend(local_beentry->proc_number).
Also, shouldn't this patch bump catversion?
Regards,
Kuba
The new status of this patch is: Waiting on Author
^ permalink raw reply [nested|flat] 68+ messages in thread
* Re: Adding per backend commit and rollback counters
@ 2026-03-31 09:24 Bertrand Drouvot <[email protected]>
parent: Kuba Knysiak <[email protected]>
0 siblings, 1 reply; 68+ messages in thread
From: Bertrand Drouvot @ 2026-03-31 09:24 UTC (permalink / raw)
To: Kuba Knysiak <[email protected]>; +Cc: [email protected]
Hi,
On Mon, Mar 30, 2026 at 08:19:13PM +0000, Kuba Knysiak wrote:
> Hello,
> after reviewing the patch together with Miłosz, we found the following:
Thanks for the review!
> - In pgstatfuncs.c, we call pgstat_fetch_stat_backend_by_pid(beentry->st_procpid, NULL)
> for each backend row. That path acquires ProcArrayLock via BackendPidGetProc(),
> so this repeats lock acquisition for every row. We could simplify this and avoid
> taking the lock altogether by fetching directly with
> pgstat_fetch_stat_backend(local_beentry->proc_number).
Yeah, I think that's a good point. Done that way in the attached. Also adding a
check on the backend type as it was done in pgstat_fetch_stat_backend_by_pid().
> Also, shouldn't this patch bump catversion?
Yes and that was mentioned in the 0003 commit message. We usually don't change
it in the patch itself (could easily produce rebase noise) but just put an
XXX in the commit message so that it's not forgoten when pushed.
Regards,
--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
^ permalink raw reply [nested|flat] 68+ messages in thread
* Re: Adding per backend commit and rollback counters
@ 2026-07-06 11:41 Nishant Sharma <[email protected]>
parent: Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 68+ messages in thread
From: Nishant Sharma @ 2026-07-06 11:41 UTC (permalink / raw)
To: Bertrand Drouvot <[email protected]>; +Cc: Kuba Knysiak <[email protected]>; [email protected]
Thanks for the v5 patch set!
Here are my review comments:
1) Patches need re-base. Not able to apply.
2) PGSTAT_BACKEND_FLUSH_XACT collision with newly committed
PGSTAT_BACKEND_FLUSH_LOCK.
3) What if pgStatXactCommit and pgStatXactRollback are 0? We unnecessarily
make backend_has_xactstats as true while updating the pending struct
values. In this process unnecessary ref_lock would be taken and
stats.xact_commit, stats.xact_rollback would be updated with 0 and then
ref_lock is unlocked.
4) PendingBackendStats was static but it was removed in this change, yet
the comment above still mentions it. Also it is killing the purpose of
"Utility routines to report I/O stats for backends ..." comment mentioned
in pgstat_backend.c. It appears the existing helper I/O routines' purpose
is eliminated. This doesn't look good.
4) I don't see any function using plural form like
pg_stat_get_backend_transactions in pg_proc.dat
5) The thread started with only commit and rollback counters, but xid was
added in v3, along with the idea of adding more, such as "seqscans, vacuum
count, analyze count...". This makes me curious: why can't these other
counters be added in this same thread? If these others aren't added now,
why was xid added? I suggest this thread should only include commit and
rollback counters, and xid should be added with the other metrics in a new
thread.
Regards,
Nishant Sharma,
EDB, Pune.
https://www.enterprisedb.com/
^ permalink raw reply [nested|flat] 68+ messages in thread
end of thread, other threads:[~2026-07-06 11:41 UTC | newest]
Thread overview: 68+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2024-03-29 15:43 [PATCH v18] Avoid orphaned objects dependencies Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v4 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v3 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v5 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v3 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v2] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v1] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v1] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v3 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v2] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v2] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v5 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v4 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v2] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v1] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v5 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v5 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v4 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v1] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v1] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v3 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v2] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v5 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v3 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v1] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v5 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v4 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v4 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v3 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v4 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v5 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v2] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v1] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v2] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v3 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v4 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v1] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v1] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v4 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v1] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v3 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v5 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v2] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v4 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v2] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v5 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v4 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v5 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v1] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v3 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v5 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v3 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v1] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v2] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v5 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v3 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v4 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v4 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v2] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v2] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 08:14 [PATCH v3 1/3] Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-04 14:20 Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-07 08:17 ` Re: Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-10 07:47 ` Re: Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2025-08-28 16:07 ` Re: Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2026-03-30 20:19 ` Re: Adding per backend commit and rollback counters Kuba Knysiak <[email protected]>
2026-03-31 09:24 ` Re: Adding per backend commit and rollback counters Bertrand Drouvot <[email protected]>
2026-07-06 11:41 ` Re: Adding per backend commit and rollback counters Nishant Sharma <[email protected]>
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