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Interview
The interview I did with Timur Akhmadeev while visiting Moscow is now online. 90 minutes ! Just got through the first 6 minutes and haven’t embarrassed myself yet:...
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12c join defect
This is a brief, temporary, note to draw attention to an item I wrote about 3 years ago demonstrating an anomaly with the plan Oracle could produce if the order of predicates in your where clause...
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Histograms
In case you’re not following me on Twitter (@jloracle) where alerts from WordPress are posted automatically, I’ve just published the first of a short series on histograms on AllThingOracle. Part 2 is...
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Hinting
I’ve spent so many years trying to explain that a “hint” to the Oracle optimizer is an order – if you know how to do it properly – that I finally decided to list the manual references that have made...
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First N
I’ve just added a little update to my posting on the 12c “First N” clause, pointing out that there are variations in the WINDOW SORT operation that can make a difference to performance. This note won’t...
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Tech13 Agenda
It’s coming up to the time when I have to think about which presentations to go to at UKOUG Tech13 – always difficult to decide whether to see topics I’m familiar with to find out how much I didn’t...
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Virtual Columns
This is just a temporary note to let people know I’ve added an update to my Virtual Stats article, highlighting a possible performance threat when you gather stats. I’ll be deleting this note in a...
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RMOUG
My provisional agenda for Training Days 2014 Wednesday: 3:15 I present “Selectivity and how Oracle calculates it” Thursday: 8:30 – 9:30 (Difficult choice) Iordan Iotzov – How sure is the optimizer...
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Quiz
To create an index on a table (with no existing indexes) Oracle has to start by doing a tablescan. What’s the difference between the tablescan it uses for a B-tree index and the tablescan it uses for a...
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12 notes
This is just a temporary note to advertise the fact that I’ve added Steve Karam’s collation of blog links on 12c features to the top of the list of links to the right of the page (12c Notes).
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