I see that Nigel Noble has started blogging. I’ve spent some time at the company where he works, so I know how close he gets to the bleeding edge of Oracle technology – you might want to keep an eye on what he has to say. I’ve added his URL to the list of links [...]
I’ve just taken a quick look at the Calendar and it appears to be 2010. However I’m still seeing, and being asked, to refresh a number of test databases using schema mode exports. This can present a challenge because there are a number of database objects that typically aren’t created by a schema mode import. [...]
A basic little post to conclude this discussion. The issues regarding whether to go for single column indexes vs. concatenated indexes are similar for Bitmap indexes as they are for B-Tree indexes. It’s generally more efficient to access a concatenated index as it’s only the one index with less processing and less throwaway rowids/rows [...]
The most significant question to ask when thinking about adding a new index: “Will the index eliminate significantly more work than it introduces (at the moments when it really matters) ?” A few examples of “moments that matter”: Bulk housekeeping Highly concurrent OLTP activity Frequent high-precision reporting Acceptance testing for side effects [Back to Philosophy [...]
This is a short note to point out that I just added to the Public Appearances page the next conference organized by the AOUG in Vienna. It will take place on June 15. My talk will be about edition-based redefinition. The full agenda (incl. abstracts) is available here. It is interesting to point out that [...]
It is one of those things that I cannot remember if it was something I knew but forgot - or just never knew.
His example makes the point nicely, you have to appreciate those little test scripts for that. You can clearly see what a difference an order by might make on a the size of a result set set across the network.
Yet another reason to look at bulk processing - the more reasons the better...
In a recent discussion in the comments of a blog item by Charles Hooper, I made a comment about how hard it is to be accurate (and unambiguous) when talking about the space needed for a rowid. So I thought I’d try to list all the possible options for rowids that you might find in [...]
Last chance to book: I’ll be speaking in Boston, New York, and Cleveland the week after next. Dates and topics: Boston: 17th – Writing Optimal SQL Boston: 18th – Troubleshooting and Tuning New York: 19th May – Writing Optimal SQL Cleveland: 20th May – All about Execution Plans New York is fully booked with a waiting [...]
By: Harald van Breederode