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performance

Why oh Why Do We Still Not Have a Fast Bulk “SQL*Unloader” Facility?

Way back in 2004 I was working at the UK side of the Human Genome project. We were creating a massive store of DNA sequences in an Oracle database (this was one of two world-wide available stores of this information, for free & open use by anyone {* see note!}). The database was, for back then, enormous at 5-6TB. And we knew it would approx double every 12 months (and it did, it was 28TB when I had to migrate it to Oracle 10 in 2006, over 40TB 6 months later and grew to half a petabyte before it was moved to another organisation). And were contemplating storing similar massive volumes in Oracle – Protein, RNA and other sequence stores, huge numbers of cytological images (sorry, microscope slides).

Do you suffer from Storage Stockholm Syndrome?

The last year at DSSD (now a part of Dell EMC) has been an extremely interesting one for me, and I’ve learned a great deal, which is always good. Some of the lessons have been surprising, though… One of them is what I will rather dramatically refer to as Storage Stockholm Syndrome. Stockholm Syndrome is … Continue reading "Do you suffer from Storage Stockholm Syndrome?"

Do you suffer from Storage Stockholm Syndrome?

The last year at DSSD (now a part of Dell EMC) has been an extremely interesting one for me, and I’ve learned a great deal, which is always good. Some of the lessons have been surprising, though… One of them is what I will rather dramatically refer to as Storage Stockholm Syndrome. Stockholm Syndrome is … Continue reading "Do you suffer from Storage Stockholm Syndrome?"

Do you suffer from Storage Stockholm Syndrome?

The last year at DSSD (now a part of Dell EMC) has been an extremely interesting one for me, and I’ve learned a great deal, which is always good. Some of the lessons have been surprising, though… One of them is what I will rather dramatically refer to as Storage Stockholm Syndrome. Stockholm Syndrome is … Continue reading "Do you suffer from Storage Stockholm Syndrome?"

Delete/Insert

Many of the questions that appear on OTN are deceptively simple until you start thinking carefully about the implications; one such showed up a little while ago:

What i want to do is to delete rows from table where it matches condition upper(CATEGORY_DESCRIPTION) like ‘%BOOK%’.

At the same time i want these rows to be inserted into other table.

The first problem is this: how carefully does the requirement need to be stated before you can decide how to address it? Trying to imagine awkward scenarios, or boundary conditions, can help to clarify the issue.

If you delete before you insert, how do you find the data to insert ?

Friday Philosophy – Your Experience can Keep You Ignorant

This week I was in an excellent presentation by Kerry Osborne about Outlines, SQL profiles, SQL patches and SQL Baselines. I’ve used three of those features in anger but when I looked at SQL Patches I just could not understand why you would use them – they looked to me like a very limited version of SQL Profiles.

Oracle Database Cloud (DBaaS) Performance Consistency - Part 7

This part of the series is supposed to cover the results of I/O related tests performed on the Amazon RDS Oracle cloud instance.

As mentioned in the previous part of this series I've only used the "General Purpose SSD" storage type since the "Provisioned IOPS" storage was simply to expensive to me and it wasn't possible to get a trial license for that storage type.

How you should or shouldn’t design, program for, a performing database environment

My good friend Toon Koppelaars created a cool and very interesting, learning video about how…

Anniversary OICA

Happy anniversary to me!

On this day 10 years ago I published the first article in my blog. It was about the parameter optimizer_index_cost_adj (hence OICA), a parameter that has been a  source of many performance problems and baffled DBAs over the years and, if you read my first blog posting and follow the links, a parameter that should almost certainly be left untouched.