2026-03-12 20:23:15

tpt/aot/pga_memleak.sql

@@ -0,0 +1,51 @@
+-- Copyright 2018 Tanel Poder. All rights reserved. More info at http://tanelpoder.com
+-- Licensed under the Apache License, Version 2.0. See LICENSE.txt for terms & conditions.
+
+-- Bug 16855783 : MEMORY LEAK IN PGA ON INSERT OF XMLTYPE COLUMN
+SET sqlblanklines ON;
+SET serveroutput ON;
+ 
+--drop table memleak_test_tab;
+--CREATE TABLE memleak_test_tab (my_xmltype XMLTYPE);
+ 
+DECLARE
+   l_my_varchar2 VARCHAR2(4001 CHAR); -- change this to CLOB and there will be a reduced memory leak.
+   --l_my_varchar2 CLOB;
+   l_pga_used_mb NUMBER;
+   l_dummy       NUMBER;
+   l_my_xmltype  XMLTYPE;
+BEGIN
+   -- build XML string with length of 4001 characters.
+   l_my_varchar2 := '<abc>';
+   FOR i IN 1 .. (4000/20) - 10
+   LOOP
+       l_my_varchar2 := l_my_varchar2 || '<def>1234567890</def>';   -- reduce string size by removing final 0
+   END LOOP;
+   l_my_varchar2 := l_my_varchar2 || '</abc>';
+   dbms_output.put_line('Input string length: [' || LENGTH(l_my_varchar2) || ']');
+ 
+   -- repeatedly insert the same value in a table (XMLType column)
+   l_my_xmltype := XMLTYPE(l_my_varchar2);
+   FOR i IN 1 .. 5000
+   LOOP
+      -- l_my_xmltype := XMLTYPE(l_my_varchar2);
+       INSERT INTO memleak_test_tab (my_xmltype)
+           VALUES (l_my_xmltype);
+ 
+       -- following insert throws ORA-1461 which I suppose is also a bug
+       -- ORA-1461: can bind a LONG value only for insert into a LONG column
+       -- INSERT INTO memleak_test_tab (my_xmltype)
+       --     VALUES (XMLTYPE(l_my_varchar2));
+   END LOOP;
+ 
+   ROLLBACK;
+ 
+   -- Check how much memory are we currently using
+   SELECT round(p.pga_used_mem/1024/1024, 2) INTO l_pga_used_mb
+   FROM v$session s
+   JOIN v$process p ON p.addr = s.paddr
+   WHERE s."SID"=sys_context('userenv', 'sid');
+   dbms_output.put_line('Currently used PGA: [' || l_pga_used_mb || '] MB');
+END;
+/
+