Rename helper function

This function counts the number of encryption keys in the key file
associated with the given OID. Name it accordingly.

Also remove comment about only user which is no longer true.

contrib/pg_tde/src/access/pg_tde_tdemap.c

@@ -529,7 +529,7 @@ pg_tde_delete_principal_key(Oid dbOid)
 	char		path[MAXPGPATH];
 
 	Assert(LWLockHeldByMeInMode(tde_lwlock_enc_keys(), LW_EXCLUSIVE));
-	Assert(pg_tde_count_relations(dbOid) == 0);
+	Assert(pg_tde_count_encryption_keys(dbOid) == 0);
 
 	pg_tde_set_db_file_path(dbOid, path);
 
@@ -672,17 +672,15 @@ pg_tde_find_map_entry(const RelFileLocator *rlocator, TDEMapEntryType key_type,
 }
 
 /*
- * Counts number of encrypted objects in a database.
+ * Counts number of encryption keys in a key file.
  *
  * Does not check if objects actually exist but just that they have keys in
- * the map file. For the only current caller, checking if we can use
+ * the key file.
- * FILE_COPY, this is good enough but for other workloads where a false
- * positive is more harmful this might not be.
  *
- * Works even if the database has no map file.
+ * Works even if the database has no key file.
  */
 int
-pg_tde_count_relations(Oid dbOid)
+pg_tde_count_encryption_keys(Oid dbOid)
 {
 	char		db_map_path[MAXPGPATH];
 	File		map_fd;

contrib/pg_tde/src/catalog/tde_principal_key.c

@@ -700,7 +700,7 @@ pg_tde_delete_key(PG_FUNCTION_ARGS)
 	 * If database has something encryted, we can try to fallback to the
 	 * default principal key
 	 */
-	if (pg_tde_count_relations(MyDatabaseId) != 0)
+	if (pg_tde_count_encryption_keys(MyDatabaseId) != 0)
 	{
 		default_principal_key = GetPrincipalKeyNoDefault(DEFAULT_DATA_TDE_OID, LW_EXCLUSIVE);
 		if (default_principal_key == NULL)
@@ -785,7 +785,7 @@ pg_tde_delete_default_key(PG_FUNCTION_ARGS)
 			 * delete default principal key if there are encrypted tables in
 			 * the database.
 			 */
-			if (pg_tde_count_relations(dbOid) != 0)
+			if (pg_tde_count_encryption_keys(dbOid) != 0)
 			{
 				ereport(ERROR,
 						errmsg("cannot delete default principal key"),

contrib/pg_tde/src/include/access/pg_tde_tdemap.h

@@ -92,7 +92,7 @@ extern bool pg_tde_has_smgr_key(RelFileLocator rel);
 extern InternalKey *pg_tde_get_smgr_key(RelFileLocator rel);
 extern void pg_tde_free_key_map_entry(RelFileLocator rel);
 
-extern int	pg_tde_count_relations(Oid dbOid);
+extern int	pg_tde_count_encryption_keys(Oid dbOid);
 
 extern void pg_tde_delete_tde_files(Oid dbOid);
 

contrib/pg_tde/src/pg_tde_event_capture.c

@@ -643,7 +643,7 @@ pg_tde_proccess_utility(PlannedStmt *pstmt,
 						int			count;
 
 						LWLockAcquire(tde_lwlock_enc_keys(), LW_SHARED);
-						count = pg_tde_count_relations(dbOid);
+						count = pg_tde_count_encryption_keys(dbOid);
 						LWLockRelease(tde_lwlock_enc_keys());
 
 						if (count > 0)