DB2: fix extra-ddl to create necessary explain_* tables for query plans

ebean-test/src/test/resources/extra-ddl.xml

@@ -64,4 +64,13 @@
     create index ix_ebasic_jmjb_gin2 on ebasic_json_map_json_b using gin(content jsonb_path_ops);
   </ddl-script>
 
+  <ddl-script name="db2 explain tables" platforms="db2">
+delimiter $$
+BEGIN
+IF NOT EXISTS (SELECT * FROM SYSCAT.TABLES WHERE TABSCHEMA = CURRENT SCHEMA AND TABNAME = 'EXPLAIN_STREAM') THEN
+call SYSPROC.SYSINSTALLOBJECTS( 'EXPLAIN', 'C' , '', CURRENT SCHEMA );
+END IF;
+END;$$
+  </ddl-script>
+
 </extra-ddl>