diff --git a/doc/src/sgml/ref/create_database.sgml b/doc/src/sgml/ref/create_database.sgml
index cf33746c1e2..cf0d53b3014 100644
--- a/doc/src/sgml/ref/create_database.sgml
+++ b/doc/src/sgml/ref/create_database.sgml
@@ -258,7 +258,8 @@ CREATE DATABASE name
The CONNECTION LIMIT> option is only enforced approximately;
if two new sessions start at about the same time when just one
connection slot> remains for the database, it is possible that
- both will fail. Also, the limit is not enforced against superusers.
+ both will fail. Also, the limit is not enforced against superusers or
+ background worker processes.
diff --git a/doc/src/sgml/ref/create_role.sgml b/doc/src/sgml/ref/create_role.sgml
index a3b8ed9ab4c..2ae576ede69 100644
--- a/doc/src/sgml/ref/create_role.sgml
+++ b/doc/src/sgml/ref/create_role.sgml
@@ -198,7 +198,10 @@ CREATE ROLE name [ [ WITH ]
If role can log in, this specifies how many concurrent connections
- the role can make. -1 (the default) means no limit.
+ the role can make. -1 (the default) means no limit. Note that only
+ normal connections are counted towards this limit. Neither prepared
+ transactions nor background worker connections are counted towards
+ this limit.
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 5415604993a..ea7bfa0578b 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -420,6 +420,7 @@ MarkAsPreparing(TransactionId xid, const char *gid,
proc->backendId = InvalidBackendId;
proc->databaseId = databaseid;
proc->roleId = owner;
+ proc->isBackgroundWorker = false;
proc->lwWaiting = false;
proc->lwWaitMode = 0;
proc->waitLock = NULL;
diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index 4adb286d5b5..651c561dfd5 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -2751,6 +2751,38 @@ CountDBBackends(Oid databaseid)
return count;
}
+/*
+ * CountDBConnections --- counts database backends ignoring any background
+ * worker processes
+ */
+int
+CountDBConnections(Oid databaseid)
+{
+ ProcArrayStruct *arrayP = procArray;
+ int count = 0;
+ int index;
+
+ LWLockAcquire(ProcArrayLock, LW_SHARED);
+
+ for (index = 0; index < arrayP->numProcs; index++)
+ {
+ int pgprocno = arrayP->pgprocnos[index];
+ volatile PGPROC *proc = &allProcs[pgprocno];
+
+ if (proc->pid == 0)
+ continue; /* do not count prepared xacts */
+ if (proc->isBackgroundWorker)
+ continue; /* do not count background workers */
+ if (!OidIsValid(databaseid) ||
+ proc->databaseId == databaseid)
+ count++;
+ }
+
+ LWLockRelease(ProcArrayLock);
+
+ return count;
+}
+
/*
* CancelDBBackends --- cancel backends that are using specified database
*/
@@ -2810,6 +2842,8 @@ CountUserBackends(Oid roleid)
if (proc->pid == 0)
continue; /* do not count prepared xacts */
+ if (proc->isBackgroundWorker)
+ continue; /* do not count background workers */
if (proc->roleId == roleid)
count++;
}
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index 9a758bd9160..cb6e1e3e5bc 100644
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -372,6 +372,7 @@ InitProcess(void)
MyProc->backendId = InvalidBackendId;
MyProc->databaseId = InvalidOid;
MyProc->roleId = InvalidOid;
+ MyProc->isBackgroundWorker = IsBackgroundWorker;
MyPgXact->delayChkpt = false;
MyPgXact->vacuumFlags = 0;
/* NB -- autovac launcher intentionally does not set IS_AUTOVACUUM */
@@ -544,6 +545,7 @@ InitAuxiliaryProcess(void)
MyProc->backendId = InvalidBackendId;
MyProc->databaseId = InvalidOid;
MyProc->roleId = InvalidOid;
+ MyProc->isBackgroundWorker = IsBackgroundWorker;
MyPgXact->delayChkpt = false;
MyPgXact->vacuumFlags = 0;
MyProc->lwWaiting = false;
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index 824d5abf11f..cde4a798b62 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -350,7 +350,7 @@ CheckMyDatabase(const char *name, bool am_superuser)
*/
if (dbform->datconnlimit >= 0 &&
!am_superuser &&
- CountDBBackends(MyDatabaseId) > dbform->datconnlimit)
+ CountDBConnections(MyDatabaseId) > dbform->datconnlimit)
ereport(FATAL,
(errcode(ERRCODE_TOO_MANY_CONNECTIONS),
errmsg("too many connections for database \"%s\"",
diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h
index 775c66a1971..c44d82b90c0 100644
--- a/src/include/storage/proc.h
+++ b/src/include/storage/proc.h
@@ -102,6 +102,8 @@ struct PGPROC
Oid databaseId; /* OID of database this backend is using */
Oid roleId; /* OID of role using this backend */
+ bool isBackgroundWorker; /* true if background worker. */
+
/*
* While in hot standby mode, shows that a conflict signal has been sent
* for the current transaction. Set/cleared while holding ProcArrayLock,
diff --git a/src/include/storage/procarray.h b/src/include/storage/procarray.h
index dd37c0cb070..ecc3c4a4f63 100644
--- a/src/include/storage/procarray.h
+++ b/src/include/storage/procarray.h
@@ -73,6 +73,7 @@ extern pid_t CancelVirtualTransaction(VirtualTransactionId vxid, ProcSignalReaso
extern bool MinimumActiveBackends(int min);
extern int CountDBBackends(Oid databaseid);
+extern int CountDBConnections(Oid databaseid);
extern void CancelDBBackends(Oid databaseid, ProcSignalReason sigmode, bool conflictPending);
extern int CountUserBackends(Oid roleid);
extern bool CountOtherDBBackends(Oid databaseId,