diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index aa67f75..a5d88c1 100644
*** a/src/backend/utils/init/postinit.c
--- b/src/backend/utils/init/postinit.c
*************** InitPostgres(const char *in_dbname, Oid 
*** 848,865 ****
  			strcpy(out_dbname, dbname);
  	}
  
- 	/* Now we can mark our PGPROC entry with the database ID */
- 	/* (We assume this is an atomic store so no lock is needed) */
- 	MyProc->databaseId = MyDatabaseId;
- 
- 	/*
- 	 * We established a catalog snapshot while reading pg_authid and/or
- 	 * pg_database; but until we have set up MyDatabaseId, we won't react to
- 	 * incoming sinval messages for unshared catalogs, so we won't realize it
- 	 * if the snapshot has been invalidated.  Assume it's no good anymore.
- 	 */
- 	InvalidateCatalogSnapshot();
- 
  	/*
  	 * Now, take a writer's lock on the database we are trying to connect to.
  	 * If there is a concurrently running DROP DATABASE on that database, this
--- 848,853 ----
*************** InitPostgres(const char *in_dbname, Oid 
*** 867,875 ****
  	 * pg_database).
  	 *
  	 * Note that the lock is not held long, only until the end of this startup
! 	 * transaction.  This is OK since we are already advertising our use of
! 	 * the database in the PGPROC array; anyone trying a DROP DATABASE after
! 	 * this point will see us there.
  	 *
  	 * Note: use of RowExclusiveLock here is reasonable because we envision
  	 * our session as being a concurrent writer of the database.  If we had a
--- 855,868 ----
  	 * pg_database).
  	 *
  	 * Note that the lock is not held long, only until the end of this startup
! 	 * transaction.  This is OK since we will advertise our use of the
! 	 * database in the PGPROC array before dropping the lock (in fact, that's
! 	 * the next thing to do).  Anyone trying a DROP DATABASE after this point
! 	 * will see us in PGPROC once they have the lock.
! 	 *
! 	 * Ordering is important here because we don't want to advertise ourselves
! 	 * as being in this database until we have the lock; otherwise we create
! 	 * what amounts to a deadlock with CountOtherDBBackends().
  	 *
  	 * Note: use of RowExclusiveLock here is reasonable because we envision
  	 * our session as being a concurrent writer of the database.  If we had a
*************** InitPostgres(const char *in_dbname, Oid 
*** 881,886 ****
--- 874,891 ----
  		LockSharedObject(DatabaseRelationId, MyDatabaseId, 0,
  						 RowExclusiveLock);
  
+ 	/* Now we can mark our PGPROC entry with the database ID */
+ 	/* (We assume this is an atomic store so no lock is needed) */
+ 	MyProc->databaseId = MyDatabaseId;
+ 
+ 	/*
+ 	 * We established a catalog snapshot while reading pg_authid and/or
+ 	 * pg_database; but until we have set up MyDatabaseId, we won't react to
+ 	 * incoming sinval messages for unshared catalogs, so we won't realize it
+ 	 * if the snapshot has been invalidated.  Assume it's no good anymore.
+ 	 */
+ 	InvalidateCatalogSnapshot();
+ 
  	/*
  	 * Recheck pg_database to make sure the target database hasn't gone away.
  	 * If there was a concurrent DROP DATABASE, this ensures we will die