2026-03-12 20:23:15

tpt/aot/06_libcache_deadlock.sql

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+-- 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.
+
+-- Script written based on Alex Nuijten's finding:
+--  http://nuijten.blogspot.com/2015/06/deadlock-with-virtual-column.html
+--
+--  This should be reproducible all the way up to 12.1.0.2 versions (like the Oracle 12cR1 Developer VM)
+
+DROP TABLE t_dl;
+CREATE TABLE t_dl AS SELECT dummy a, rownum b FROM dual;
+
+CREATE OR REPLACE FUNCTION VC (p_a in t_dl.a%TYPE ,p_b in t_dl.b%TYPE) RETURN VARCHAR2 DETERMINISTIC
+IS
+BEGIN
+    RETURN p_a || p_b;
+END vc;
+/
+
+ALTER TABLE t_dl ADD c AS (vc (a, b));
+
+TRUNCATE TABLE t_dl;
+
+
+-- Back in Oracle 9i days you could have used this too (not anymore):
+
+-- SQL> CREATE OR REPLACE PROCEDURE p1 AS BEGIN p2; END;
+--   2  /
+-- 
+-- Warning: Procedure created with compilation errors.
+-- 
+-- SQL> 
+-- SQL> CREATE OR REPLACE PROCEDURE p2 AS BEGIN p1; END;
+--   2  /
+-- 
+-- Warning: Procedure created with compilation errors.
+--  
+-- SQL> ALTER PROCEDURE p1 COMPILE;
+-- ALTER PROCEDURE p1 COMPILE
+-- *
+-- ERROR at line 1:
+-- ORA-04020: deadlock detected while trying to lock object SYS.P1
+