Skip to Main Content
Oracle PL/SQL Programming: A Developer's Workbook
book

Oracle PL/SQL Programming: A Developer's Workbook

by Steven Feuerstein, Andrew Odewahn
May 2000
Intermediate to advanced content levelIntermediate to advanced
594 pages
11h 32m
English
O'Reilly Media, Inc.
Content preview from Oracle PL/SQL Programming: A Developer's Workbook

Expert

Q:

17-16.

You can assert only WNDS. Clearly, it reads from the database. In addition, DBMS_OUTPUT.PUT_LINE asserts only WNDS and RNDS; it does, in fact, write to the DBMS_OUTPUT buffer and also reads the values of data structures for the buffer. You can assert only the intersection of the purity levels of all referenced programs.

Q:

17-17.

The following implementation of this trace function is really just a “pass-through” to DBMS_OUTPUT.PUT_LINE:


/* Filename on web page: traceit.sf */
CREATE OR REPLACE FUNCTION traceit (
   tab IN VARCHAR2,
   rowid_in IN ROWID)
   RETURN INTEGER
IS
BEGIN
   DBMS_OUTPUT.PUT_LINE (tab || '-' || ROWIDTOCHAR (rowid_in));
   RETURN 0;
EXCEPTION
   WHEN OTHERS
   THEN
      DBMS_OUTPUT.ENABLE (1000000);
      traceit (tab, rowid_in);
END;
/

I cannot call this procedure directly in SQL, so I put it inside a function that always returns 0, but in the process put information into the DBMS_OUTPUT buffer. I also added an exception section to trap and automatically correct for an error that might arise from the DBMS_OUTPUT buffer’s being too small.

Q:

17-18.

Here is one possible implementation:

CREATE OR REPLACE FUNCTION traceit (
   tab IN VARCHAR2,
   rowid_in IN ROWID)
   RETURN INTEGER
IS
   stat PLS_INTEGER;
BEGIN
   DBMS_PIPE.RESET_BUFFER;
   DBMS_PIPE.PACK_MESSAGE (tab);
   DBMS_PIPE.PACK_MESSAGE_ROWID (rowid_in);
   stat := DBMS_PIPE.SEND_MESSAGE ('SQLtrace');
   RETURN stat;
END;
/

You might decide to use a pipe-based ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

Oracle Database 12c PL/SQL Programming

Oracle Database 12c PL/SQL Programming

Michael McLaughlin
Oracle PL/SQL for DBAs

Oracle PL/SQL for DBAs

Arup Nanda, Steven Feuerstein
Oracle PL/SQL For Dummies

Oracle PL/SQL For Dummies

Michael Rosenblum, Paul Dorsey

Publisher Resources

ISBN: 9781449324070Supplemental ContentErrata Page