Oracle Batch Job Logging – a framework for domestic harmony

Like most men, I have a standard of tidiness and cleanliness that I think of as “Bloke Clean”.
Deb’s standards are rather higher ( she would say normal). The difference can occasionally be a source of tension.
“Maybe I’ll just run off with that Steven Feuerstein bloke !”, she may have said during one of our discussions about the state of the study.
“Oh really ?”, I might retort, “and what’s he got that I haven’t ?”,
“Money, fame, talent and his own framework…not to mention a cleaner, I’ll bet”.
“Well…at least I have more hair”, I might say, disconcerted by her surprisingly comprehensive knowledge of someone who, it must be said, is not exactly famous outside of the wonderful world of Oracle.
“Not by much.” would probably have been the devastating reply.
Predictably, a compromise has now been reached…the upshot of which is that I’ve just spent the afternoon becoming intoxicated by the fumes from various cleaning products…and the study is now gleaming and all the papers filed away…and we’re getting a cleaner.
As for the money, fame and talent…well, I’ll just have to make do with the framework for now.
Truth be told, calling it a framework is overstating things a bit. But hey, it does give me an excuse to come up with a (possibly) amusing name. Continue reading

Running a Windows Batch file from DBMS_SCHEDULER

In an ideal world ….

Luton would have won the play-off final
I would have won the lottery by now
…and Oracle databases would run on Linux.

Out in the real world however, there are times when Oracle running on a Windows server is just unavoidable.
That’ll be the Real World with real data and real security issues, mixed in with – possibly – the real need to initiate a batch script from inside the database.
What follows are details of how to do this in Oracle 10g R2 running on a Windows server. Continue reading

Implicit Cursors are from Venus, Explicit Cursors are from Mars

Domestic bliss. There’s nothing like it. There’s certainly nothing like it in our house, particularly when I indulge in one of my endearing little foibles that is guaranteed to get Deb pouting like Angelina Jolie suffering a nasty reaction to a wasp-sting.
Whether it’s leaving the toilet seat up, or hanging my clothes up on the nearest floor, there are some days where I just can’t seem to do anything right.
Having said that, I must confess that I myself, am not a model of toleration. My own personal pout trigger is a query that looks something like this :

SELECT NVL(COUNT(*), 0)
FROM some_table;

I’ve seen this quite a bit recently, usually in the form of an explicit cursor.
Once I’ve got the rant about this out of my system, I’ll then look at how you might make single-row sub-queries a bit more efficient without ending up knee-deep in implicit cursors.
I’ll also ponder what it actually is that we really know about cursors. Continue reading

Getting APEX to play with Ref Cursors

It’s that time of year again. Things are a bit tense around the house.
The other morning, I woke up to find that someone had placed a leek in my slippers.
Yes it’s Six Nations time again. England are playing Wales on Saturday. The lovely Debbie is getting into the spirit of the occasion…by exhibiting extreme antagonism to all things English.

Whilst the patriot in me would like to cheer on the Red Rose on Saturday, I have decided that discretion ( or in this case, cowardice) is the better part of valour and will instead, sit quietly in the corner, hoping for a draw. That way, I’ve not sold out completely and next week will be far more pleasant if Wales have not lost.

For those readers who know Rugby Union as merely another one of those odd games that we English let our former colonies win at, all you need to know is, the Welsh take this sport very seriously.

In the meantime, I’m trying to keep a low profile, which means playing around with APEX 4.1.

The heady excitement of discovering the first decent GUI development environment for PL/SQL programmers since Oracle Forms is now starting to be replaced by some of the harsh realities of modern web development.
For example, how can I reuse all those terribly useful functions that return Ref Cursors ?
I mean, they work fine in PHP and various other languages, and APEX itself is written in PL/SQL. Should be easy, shouldn’t it ?

Er, no.

APEX simply refuses to play. “I laugh in the face of your weakly typed Ref Cursor” it seems to say. Clearly, some persuasion is required if I’m not to end up with a lot of code locked away in my APEX application, unusable by any other programming language I might want to use to build a web front-end for my database.
The way to an APEX application’s heart is, as will become apparent, through Pipelined functions. Continue reading

Nested Tables – Flat-packed data in an Oracle Table

In the aftermath of the holiday season, there follows the inevitable January sales.
This year, I have been spared the inevitable trudge around the stores. Deb has hurt her knee and has therefore been restricted to browsing on-line.

I thought she “kneeded” cheering up, but to date, my attempts at lightening the mood, seem only to have given her the “kneedle”.

Sitting quietly, whilst Deb is wandering through various furniture store websites, I had cause to reflect on Oracle’s own version of Nested Tables.
These were introduced way back in Oracle 8, when Oracle confidently predicted that the Object-Relational Database was the way of the future.
Imagine if they were just bringing this feature out now. You can picture it. Larry would have spent months making disparaging remarks about IKEA’s occasional table range, before unveiling his own version, which was better, cheaper and more efficient.

Whilst you’re never going to be able to rest your pint on one, a Nested Table in Oracle may be useful on occasion. Continue reading

Help – DBMS_SCHEDULER keeps Spamming me…and can’t tell the time either

Sundays – a day of rest. Certainly true for me. Sunday morning is a time for lazing around leafing through the colour supplements and thinking about nothing in particular. Sunday 23rd October was a little bit different.
Wide-awake at 8 am ( I didn’t know that there was such a time as 8am on a Sunday), like several million others, I was wondering what would confront the All Blacks – the Gallic flair with which France had swept aside England or the Gallic shrug with which they had surrendered to Tonga ?
Look, I’m not really a New Zealander. Yes, I was born in Auckland but both my parents are English and I’ve lived most of my life in England. However, like anyone with a connection to the Land of the Long White Cloud, there is a part of my soul, however small, that takes the form of a Rugby ball.
At the end of the match, I was able to join my “fellow” Kiwis in, not so much paroxysms of joy as a huge collective sigh of relief.

On the whole though, I’d rather not have to see Sunday morning from that early on. So, if there is, for example, something that needs to run on my database on a Sunday morning, I’d rather the database just did it without my intervention.

What I plan to do here is :

  1. set up a scheduler job
  2. explore the ways in which we can control whether a class of job runs on a given database
  3. stop jobs running on database startup
  4. teach the scheduler how to tell the time – especially in terms of daylight saving

Continue reading