performance

marco's picture

Oracle OpenWorld 2014 – Datatype context…?!

The native JSON database functionality presentations are done. If you want to experience first hand what you can do with those new operators during Oracle...
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marco's picture

Oracle OpenWorld 2014 – In the middle of it…

It’s funny this might be one of the first time in years that my strange performance hobbies I have (on the side of my regular...
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fritshoogland's picture

Oracle IO wait events: db file sequential read

(the details are investigated and specific to Oracle’s database implementation on Linux x86_64)

Exadata IO: This event is not used with Exadata storage, ‘cell single block physical read’ is used instead.
Parameters:
p1: file#
p2: block#
p3: blocks

Despite p3 listing the number of blocks, I haven’t seen a db file sequential read event that read more than one block ever. Of course this could change in a newer release.

Jonathan Lewis's picture

In-memory Aggregation

The title of this piece is the name given to a new feature in 12.1.0.2, and since I’ve recently blogged about a limitation of the in-memory option I thought I’d pick this feature as the next obvious thing to blog about. This is a bit of a non sequitur, though, as the feature seems to have nothing whatsoever to do with the in-memory option; instead it’s a cunning mechanism combining aspects of the star-transformation (but without the bitmap indexes), Bloom filters, and “group-by” placement to minimise the cost of aggregation over high-volume joins.

Here’s a small data set I’ll use to demonstrate the feature:

Jonathan Lewis's picture

LOB Length

It’s funny how you can make little savings in work all over the place in Oracle if you’re prepared to look a little closely at what’s going on. Here’s a quirky little example with LOBs and function calls that might just have some greater relevance in other situations. Here’s a little data set, and two queries that I might run against it:

marco's picture

Oracle Database 12.1.0.2.0 – Turning OFF the In-Memory Database option

So how to turn it the option off/disabled…As a privileged database user: > Just don’t set the INMEMORY_SIZE parameter to a non zero value…(the default...
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marco's picture

Oracle Database 12.1.0.2.0 – Native JSON Support (1)

Oracle Database 12.1.0.2 has now native support build-in for handling JSON (Javascript Object Notation) data. Oracle Database supports JSON natively with relational database features, including...
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marco's picture

Oracle Database 12.1.0.2.0 – New Features

The world around us is changing and new stuff in the Oracle database arena is nowadays released on patch level. Although not many new features...
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marco's picture

Using Database In-Memory Column Store with Complex Datatypes (1)

The Oracle database 12.1.0.2 version, with the In-Memory option, isn’t yet released, but a lot of detail is already out there since it’s announcement by...
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