TweetShare1SharePin1 SharesReports of this blogs death have been greatly exaggerated. It has been very quiet here though while I worked on getting the Swedish part of Miracle started. It is now rocking the Stockholm market so it’s time to get back into more geeky stuff. Talking of which. I have encountered Liquibase for database versioning time after time and always come to the conclusion that it is not what a DBA want to use. I recently took it out for a […]
DBA
Is your database secure? Are you sure? Are you *really* sure?
TweetShareSharePin0 SharesA friend and at the time co-worker at Kentor AB found this bug. He found the bug and had the tenacity to track down and prove that it was a bug and not just a flaw in the logging mechanism where this first was indicated to occur. Today is the day when I can finally speak about a bug I asked for a peer review on over a year ago. I had to pull that blog post offline when […]
Improving data move on EXADATA V
TweetShareSharePin0 SharesWrap-up This is the last post in this series and I’ll not introduce anything new here, but rather just summarise the changes explained and talk a bit about the value the solution delivers to the organisation. Let’s first review the situation we faced before implementing the changes. The cost of writing the log-records to the database was that all the parallel writing from many different sources was such that it introduced severe bottlenecks to the point that the logging feature […]
Improving data move on EXADATA IV
TweetShareSharePin0 SharesReducing storage requirements In the last post in this series I talked about how we sped up the move of data from operational to historical tables from around 16 hours down to just seconds. You find that post here. The last area of concern was the amount of storage this took and would take in the future. As it was currently taking 1.5 TB it would be a fairly large chunk of the available storage and that raised concerns […]
Improving data move on EXADATA III
TweetShareSharePin0 SharesMoving to history tables In the last post I talked about how we made the speed of actually writing all those log-records much faster. It has to date been so fast that no a single report of a problem has been filed. you find that post here. Once the data was written to the log-tables, it had to be moved to the history tables.This was a process that took around 16 hours. It was never allowed to run for […]
Improving data move on EXADATA II
TweetShareSharePin0 SharesWriting log records The last post in this series introduced the problem briefly. You find that post here. In this post I’ll talk about the changes made to make that writing of log records fast enough. There were 50 million records that was written. Each of them pretty much in its own transaction. Of course the commit activity caused problem, as did log buffer issues. Some of this could be somewhat remedied with configuration. The big issue though was that […]
Faster data move on EXADATA I
TweetShareSharePin0 SharesIntroduction In my work among other things I tune and tweak solutions for EXADATA. Today I’ll write about a big improvement we achieved with a process that moves data from the operational tables to the ones where the history is stored. This will not be a technical post. While I talk about using advanced technologies, I will not discuss code or deep details of them in this post. And yes, when I say post, I mean a series of […]
Can table security be circumvented with a view? (Bug for peer review)
TweetShareSharePin0 SharesMy collegue Daniel Ekberg (@dan_ekb) stumbled on a very strange issue the other day. After having tested it in three separate environments and on both 10g and 11g (11.2.0.1 and 11.2.0.2) we have resigned to believing that this may actually be a bug. If it is, it is a LARGE one. Essentially we can perform insert, update, and delete on a table on which we have only been given select rights. Yes, it sounds as if it really wouldn’t […]
SQL Access to the alert-log in 11g and an oddity
TweetShareSharePin0 SharesQuite a while ago I wrote about how to setup the alert log as an external table. Since then 11g has been introduced and is now widely used. It of course changes the location and makes the alert log an xml file. While it is possible to select from it using xml functions like Laurent Schneider does here, it is still a bit cumbersome. Tanel Poder (@TanelPoder) found a nicer way by using X$DBGALERTEXT which does a really nice job […]
OOW 2010 Develop Keynote
TweetShareSharePin0 SharesYes, this post is a little out of order as it clearly didn’t take place after the Thursday afternoon sessions. I missed it during the conference so I had to catch up on it later on the on demand site. I thought it was interesting enough to write up a few notes. It was held by Tom Kyte and the subject was “What’s new in database development”. It’d be more correct to say Oracle development than database development as […]