COPY to a relation should keep write lock till transaction commit.

Thanks to Hiroshi for spotting the problem.

diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index 9a33a08779d7d9b2a9276b75f28f86b2c22a5531..5f3f2455acda71b1329e48be2c10a3223b1488d7 100644 (file)
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -6,7 +6,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.91 1999/11/22 17:56:00 momjian Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.92 1999/11/27 21:52:53 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -257,14 +257,16 @@ DoCopy(char *relname, bool binary, bool oids, bool from, bool pipe,
        Relation        rel;
        extern char *UserName;          /* defined in global.c */
        const AclMode required_access = from ? ACL_WR : ACL_RD;
-       LOCKMODE        required_lock = from ? AccessExclusiveLock : AccessShareLock;
-       /* Note: AccessExclusive is probably overkill for copying to a relation,
-        * but that's what the existing code grabs on the rel's indices.  If
-        * this is relaxed then I think the index locks need relaxed also.
-        */
        int                     result;
 
-       rel = heap_openr(relname, required_lock);
+       /*
+        * Open and lock the relation, using the appropriate lock type.
+        *
+        * Note: AccessExclusive is probably overkill for copying to a relation,
+        * but that's what the code grabs on the rel's indices.  If this lock is
+        * relaxed then I think the index locks need relaxed also.
+        */
+       rel = heap_openr(relname, (from ? AccessExclusiveLock : AccessShareLock));
 
        result = pg_aclcheck(relname, UserName, required_access);
        if (result != ACLCHECK_OK)
@@ -349,7 +351,12 @@ DoCopy(char *relname, bool binary, bool oids, bool from, bool pipe,
                }
        }
 
-       heap_close(rel, required_lock);
+       /*
+        * Close the relation.  If reading, we can release the AccessShareLock
+        * we got; if writing, we should hold the lock until end of transaction
+        * to ensure that updates will be committed before lock is released.
+        */
+       heap_close(rel, (from ? NoLock : AccessShareLock));
 }