track DDL changes

Why is my package being invalidated? This is the question I asked myself a few times those days. In order to find out what is happening in my schema, I created this simple DDL trigger which tracks all DDL changes in my schema. CREATE TABLE AUDIT_DDL ( d date, OSUSER varchar2(255), CURRENT_USER varchar2(255), HOST varchar2(255), […]

high cost

What’s wrong with this query ? select (t6.column_value).getstringval() t6 from table(xmlsequence(extract(xmltype(‘<x/>’),’/x’))) t1, table(xmlsequence(t1.column_value))t2, table(xmlsequence(t2.column_value))t3, table(xmlsequence(t3.column_value))t4, table(xmlsequence(t4.column_value))t5, table(xmlsequence(t5.column_value))t6; T6 ———————— <x/> Elapsed: 00:00:00.01 Well, let’s check the plan : ——————————————————————– | Id | Operation | Rows | Bytes | Cost (%CPU)| Time | ——————————————————————– | 0 | SELECT STATEMENT | 18E| 15E| 18E (0)|999:59:59 | | […]