Disclaimer: I’m not posting to make me look better, we’ve all written code that we’re later ashamed of, and I’m no different!
This is some code from a system I was maintaining some time ago. I’ve kept it since then because it illustrates a number of things NOT to do:
(in_password IN VARCHAR2)
-- do NOT copy this code!!! ...
RETURN VARCHAR2 IS
CURSOR cur_rules IS
If you want to be able to create contemporary high-performing PL/SQL code, welcome to my training event in NYC (hosted by NYOUG) on November 7, 2014:
I think, it is as important as ever to follow best practices for server-side development. There are lots of options that could get the job done "now", but very few that would survive for months/years. Also, there is a constant pressure from various "alternative" solutions to (more...)
My session on "Oracle 12c for Developers" is done.Afterwards someone asks the question:
What happens when you use DBMS_REDACT with a complete row update?
My guess was that it would place the redacted data in the column, but I haven't tried it, so here goes:
create table emp
,to_char (abs (dbms_random.random)) credit_card
(object_schema => 'A'
,object_name => 'EMP'
,policy_name => 'Hide Creditcard'
It seems to me that I talked about my most recent book everywhere except for my own blog... So, let me introduce you a one and only performance tuning book dedicated to PL/SQL
This book took me much longer to write than I initially anticipated - and to be fair, that's the reason for staying quiet at the blog. I just didn't have time/energy to write everywhere :-) Although, it was fun writing - (more...)
The EOUC (EMEA Oracle User Group Community) hosts a special session on sunday during Oracle Open World. This session contains twelve things about Oracle 12c. Each of these 12 things is hosted by a different speaker, so this means that each section is only five minutes long (Strictly guarded by Debra Lilley).
Thankfully I was chosen to be one of the speaker during this special session, very excited and also very scared. (more...)
While preparing for my session at Oracle Open World on "Oracle 12c for Developers" I ran into a little remarkable thing.
When sorting a dataset, the sorting is always done last. That is what I was taught anyway. There is probably some obscure way to detect the exact execution plan, but personally I never bothered to go and investigate.
When I was created some test scripts I found there was a way to see that (more...)
Sorry for staying quiet for some time, but for some good reasons. Some of these reasons will be explained in later posts, but for now I would like to share the story I wrote upon request of Steven Feuerstein
, who asked to tell how PL/SQL impacted our life. Here is my story:
I started to work with databases already in college, but more from the data modelling/business analysis angle. When I moved to (more...)
A recent addition to my Oracle PL/SQL library is the book Oracle PL/SQL Performance Tuning Tips & Techniques by Michael Rosenblum and Dr. Paul Dorsey.
I agree with Steven Feuerstein’s review that “if you write PL/SQL or are responsible for tuning the PL/SQL code written by someone else, this book will give you a broader, deeper set of tools with which to achieve PL/SQL success”.
In the foreword of the book, Bryn Llewellyn writes:
The UTL_FILE database package is used to read from and write to operating system directories and files. By default, PUBLIC is granted execute permission on UTL_FILE. Therefore, any database account may read from and write to files in the directories specified in the UTL_FILE_DIR database initialization parameter [...] Security considerations with UTL_FILE can be mitigated by removing all directories from UTL_FILE_DIR and using the Directory functionality instead.
© Eddie Awad's Blog, (more...)
I was aware that up to Oracle 11g, a PL/SQL program wasn’t allowed use an associative array in a SQL statement. This is what happens when I try to do it.
SQL> drop table test_array purge;
SQL> create table test_array as
2 select level num_col from dual
3 connect by level <= 10;
SQL> select * from test_array;
Steven Feuerstein was dismayed when he found in a PL/SQL procedure a cursor FOR loop that contained an INSERT and an UPDATE statements.
That is a classic anti-pattern, a general pattern of coding that should be avoided. It should be avoided because the inserts and updates are changing the tables on a row-by-row basis, which maximizes the number of context switches (between SQL and PL/SQL) and consequently greatly slows the performance of the code. Fortunately, (more...)
In my previous blog post
, I took a look at the new APEX_JSON package that ships with Apex 5.0 and its capabilities for parsing JSON.
In this blog post, I am going to look at how the APEX_JSON package can be used to generate JSON from data in your database using PL/SQL.
There are multiple ways of creating JSON output using the APEX_JSON package. There are several overloaded write() procedures which can output (more...)
As I mentioned a year ago
, it looks like Apex 5.0 will include a new package called APEX_JSON for parsing and generating JSON. In this blog post, I will take a quick look at the parsing, and the next blog post will be about generating JSON output.
Since Apex 5.0 is still in Early Adopter (beta) mode and not yet released for download, we can run a query against the data dictionary (more...)
Do you need to create PDF reports from PL/SQL?
There are a number of options:
- Anton Scheffer wrote a PL/SQL package called AS_PDF3 that covers all the basics: Different fonts (including TrueType), images, and tables.
- There's the commercial PL/PDF package that has more features, such as the ability to use existing PDF documents as templates for new documents, compression, encryption, and more. There's also an extra Toolkit component which allows you to extract pages from (more...)
I have been awfully quiet on my blog lately. I think that is because I have been busy with other things, like my garden and stuff like that. There are some ‘techie’ thing I have done in the meantime, though,
I have submitted a couple of abstracts for Tech14. Hope at least one of them gets selected. I really like presenting and if it is in a different country, that is just a plus. That (more...)
email@example.com > create procedure p is begin null; end this_does_not_compile;
Warning: Procedure created with compilation errors.
firstname.lastname@example.org > show errors
Errors for PROCEDURE P:
1/32 PLS-00113: END identifier 'THIS_DOES_NOT_COMPILE' must match 'P'
at line 1, column 11
email@example.com > REM expexted
firstname.lastname@example.org > create function f return number is begin return null; end this_does_not_compile;
Warning: Function created with compilation errors.
email@example.com > (more...)
Being a huge fan of Logger, the PL/SQL logging utility, I really wanted this be to included in the project that I'm currently working on. So I downloaded it (link at the bottom of this blog) and included it in our deployment scripts. Done.... at least I thought so, but of course this wasn't the case.
The regular install script for Logger looks something like the following (parts removed and table names are changed):
There is a ‘rule’, I think it was created by Tom Kyte, stating: If you can do it in SQL, do it in SQL. I came across some code the other day that makes perfect sense to do then you are running an Oracle 10g (or earlier) instance. I rewrote the code to use only the EMP and DEPT tables to protect the suspects and maybe innocent.
The function defined is something like this:
I have reviewed the latest edition of Oracle PL/SQL Programming. This is not a book, at least for me, that I would read front to back. I use it mostly as a reference, but the great thing about this book is that you can also use this book to learn programming PL/SQL from scratch.
The book is nicely ordered into different parts, like Program structure and how to use SQL in PL/SQL (which by the (more...)