Today is a very special day for me.It’s my blog first anniversary, it has been a year since i took my first step and wrote “ORACLE 12C Automatic big table caching” 😀 . Since that i published 28 blog posts and reached 5949 views.
So thanks everyone for your support, reading, commenting and the ideas we’ve exchanged 🙂
In ORACLE 12C a new bug fix was introduced :
| 12534597 | 12.1.0.0 | Bind Peeking is disabled for remote queries |
select * from V$SYSTEM_FIX_CONTROL where bugno = ‘12534597’;
So from now on bind variable peeking will kick in also for distributed query.
Let’s run some test :
In the previous part of this series i showed how we can set the minimum number of I/O slots (_direct_io_slots) used by Async direct path read and how this can improve the throughput.In this second part i will play with different setting for the maximum I/O size “db_file_multiblock_read_count” and minimum number of outstanding I/O “_direct_io_slots” values and check there impact on throughput and CPU consumption.
Since version 11.2.0.2 ORACLE is able to adjust the number of I/O slots when using Asynch direct path read to improve bandwidth utilisation.Frits Hoogland explained this new feature in about-multiblock-reads .
Let’s begin by observing this I/O auto slots resizing in action :
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