Event Trigger Functions

• pg_event_trigger_ddl_commands

  Description: Reports running DDL commands in the ddl_command_end event trigger.

  Parameter: null

  NOTE: This function is used only in event triggers.

  Return type: oid,oid,int4,text,text,text,text,bool,pg_ddl_command.

  Example:

  openGauss=# CREATE OR REPLACE FUNCTION ddl_command_test()
  RETURNS event_trigger
  AS $$
  DECLARE
      obj record;
  BEGIN
      FOR obj IN SELECT * FROM pg_event_trigger_ddl_commands()
          LOOP
          RAISE NOTICE 'command: %',
                  obj.command_tag;
  
              RAISE NOTICE 'triggered';
          END LOOP;
  END; $$ LANGUAGE plpgsql;
  

• pg_event_trigger_dropped_objects

  Description: Makes the list of deleted objects visible to users in the sql_drop event trigger.

  Parameter: null

  NOTE: This function is used only in event triggers.

  Return types: oid,oid,int4,bool,bool,booloid,text,text,text,text,TEXTARRAY,TEXTARRAY

  Example:

  openGauss=# CREATE OR REPLACE FUNCTION test_evtrig_dropped_objects() RETURNS event_trigger
  LANGUAGE plpgsql AS $$
  DECLARE
      obj record;
  BEGIN
      FOR obj IN SELECT * FROM pg_event_trigger_dropped_objects()
      LOOP
          IF obj.object_type = 'table' THEN
                  EXECUTE format('DROP TABLE IF EXISTS audit_tbls.%I',
                      format('%s_%s', obj.schema_name, obj.object_name));
          END IF;
  
      INSERT INTO dropped_objects
          (type, schema, object) VALUES
          (obj.object_type, obj.schema_name, obj.object_identity);
      END LOOP;
  END
  $$;
  

• pg_event_trigger_table_rewrite_oid

  Description: Makes the overwritten object OIDs visible to users in the table_rewrite event trigger.

  Parameter: null

  NOTE: This function is used only in event triggers.

  Return type: oid

  Example:

  openGauss=# CREATE OR REPLACE FUNCTION test_evtrig_no_rewrite() RETURNS event_trigger
  LANGUAGE plpgsql AS $$
  BEGIN
  RAISE NOTICE 'Table ''%'' is being rewritten (reason = %)',
              pg_event_trigger_table_rewrite_oid()::regclass,
              pg_event_trigger_table_rewrite_reason();
  END;
  $$;
  

• pg_event_trigger_table_rewrite_reason

  Description: Makes reasons for rewriting objects visible to users in the table_rewrite event trigger.

  Parameter: null

  NOTE: This function is used only in event triggers.

  Return type: int4

  Example:

  openGauss=# CREATE OR REPLACE FUNCTION test_evtrig_no_rewrite() RETURNS event_trigger
  LANGUAGE plpgsql AS $$
  BEGIN
  RAISE NOTICE 'Table ''%'' is being rewritten (reason = %)',
              pg_event_trigger_table_rewrite_oid()::regclass,
              pg_event_trigger_table_rewrite_reason();
  END;
  $$;