ALTER PROPERTY GRAPH

Purpose

Changes to the underlying objects of the property graph may cause the property graph to be in an invalid state.You can revalidate a graph with ALTER PROPERTY GRAPH COMPILE.

Prerequistes

To alter a property graph in any schema except SYS and AUDSYS, you must have the ALTER ANY PROPERTY GRAPH privilege.

Syntax

alter_property_graph::=

Description of the illustration alter_property_graph.eps

Semantics

IF EXISTS

Specify IF EXISTS to alter an existing property graph.

If you specify IF NOT EXISTS with ALTER, the command fails with the error message: Incorrect IF EXISTS clause for ALTER/DROP statement.

COMPILE

Use ALTER PROPERTY GRAPH COMPILE to revalidate a graph that reports an invalid state even though it is actually valid. This happens because the dependencies of the graph to its underlying objects may be too coarse. In such cases, it may be enough to use ALTER PROPERTY GRAPH COMPILE to revalidate the property graph.

Example: How a Valid Graph May Falsely Report an Invalid State

SQL> create table tbl1(c1 number primary key, c2 number, c3 number, c4 as (c2/c3), c5 as (1 / (c2+c3)));

Table created.

SQL> create property graph g vertex tables(tbl1 properties(c2, c3, c5));

Property graph created.

SQL> select object_name, object_type, status from user_objects where object_type in ('PROPERTY GRAPH', 'TABLE');

OBJECT_NAME OBJECT_TYPE STATUS
-------------------- ----------------------- -------
G PROPERTY GRAPH VALID
TBL1 TABLE VALID

SQL> alter table tbl1 drop column c4;

Table altered.

SQL> select object_name, object_type, status from user_objects where object_type in ('PROPERTY GRAPH', 'TABLE');

OBJECT_NAME OBJECT_TYPE STATUS
-------------------- ----------------------- -------
G PROPERTY GRAPH INVALID
TBL1 TABLE VALID

SQL> alter property graph g compile;

Property graph altered.

SQL> select object_name, object_type, status from user_objects where object_type in ('PROPERTY GRAPH', 'TABLE');

OBJECT_NAME OBJECT_TYPE STATUS
-------------------- ----------------------- -------
G PROPERTY GRAPH VALID
TBL1 TABLE VALID

SQL>

If ALTER PROPERTY GRAPH COMPILE fails to revalidate the graph, then the graph enters the error state. You must then redefine the graph with CREATE OR REPLACE PROPERTY GRAPH .