Document LWTRANCHE_PARALLEL_HASH_JOIN.

Thomas Munro

Discussion: http://postgr.es/m/CAEepm=3g1hhbFzYkR_QT9RmBvsGX4UaeCtX-4Js8OOEMmFeaSQ@mail.gmail.com

Author: robertmhaas

doc/src/sgml/monitoring.sgml

@@ -845,7 +845,7 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
 
       <tbody>
        <row>
-        <entry morerows="63"><literal>LWLock</literal></entry>
+        <entry morerows="64"><literal>LWLock</literal></entry>
         <entry><literal>ShmemIndexLock</literal></entry>
         <entry>Waiting to find or allocate space in shared memory.</entry>
        </row>
@@ -1121,6 +1121,11 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
          <entry>Waiting to choose the next subplan during Parallel Append plan
          execution.</entry>
         </row>
+        <row>
+         <entry><literal>parallel_hash_join</literal></entry>
+         <entry>Waiting to allocate or exchange a chunk of memory or update
+         counters during Parallel Hash plan execution.</entry>
+        </row>
         <row>
          <entry morerows="9"><literal>Lock</literal></entry>
          <entry><literal>relation</literal></entry>

src/backend/storage/lmgr/lwlock.c

@@ -520,6 +520,7 @@ RegisterLWLockTranches(void)
 						  "shared_tuplestore");
 	LWLockRegisterTranche(LWTRANCHE_TBM, "tbm");
 	LWLockRegisterTranche(LWTRANCHE_PARALLEL_APPEND, "parallel_append");
+	LWLockRegisterTranche(LWTRANCHE_PARALLEL_HASH_JOIN, "parallel_hash_join");
 
 	/* Register named tranches. */
 	for (i = 0; i < NamedLWLockTrancheRequests; i++)