A question.
Fh.syed, October 30, 2009 - 6:24 am UTC
October 30, 2009 - 10:30 am UTC
well, it is given away for free with expert oracle database architecture.. It is a bit long in the tooth - it was 8.1.7 and before.
We are working on the update to expert oracle database architecture right now to bring it up to 11g Release 2.
A reader, October 30, 2009 - 10:36 am UTC
So If I am not wrong from your above reply, you are currently working on Expert database Architecture for 11 gr2
One quuick question when it will available to have one great book in my catalogue
Thanks
November 09, 2009 - 11:08 am UTC
Probably middle of 2010.
Solution for this
A reader, October 30, 2009 - 2:09 pm UTC
Hello Sir,
This was really a eye opener where insert are slower then select when using partition tables. But then what is the solution for this kind of things.
November 09, 2009 - 11:29 am UTC
... But then what is the solution for this kind of things....
to understand that it is a fact? I don't know why people think something is in need of a solution like this?
It necessarily takes longer to find out where to put a row away in a partitioned table.
But you do it, because you derive some overwhelming benefit from partitioning that far outstrips any of the negatives (and if you do not derive this benefit then you should ask "ok, why did I partition then?" not "how do I 'solve' a fact").
You might partition to make inserts go faster - it might take us longer to figure out where the row goes, but because we have 128 table segments and 128 index segments - we find we can insert faster overall since we have decreased contention by a factor of 128.
You might partition to make inserts go faster - because you use insert /*+ append */ to load a table, and you would like to do it from many sessions in parallel - but only one session can insert /*+ append */ into a segment at a time, so by having 128 segments - you can do 128 direct path inserts at a time - one each for each partition.
You might partition, letting inserts take longer, because the payback you get in partition elimination pays off 1,000,000 times over.
You might partition, letting inserts take longer, because the ability to purge the data with a single DDL command far outstrips any perceived performance hit.
and so on. As with all things in life, it is all about tradeoffs - understand HOW it works, understand what you need to accomplish and you can make the cost benefit analysis to determine if "you will probably be better off after doing something"
That is how to solve it.
Oleksandr Alesinskyy, November 01, 2009 - 12:17 pm UTC
I understand that this slowdown is applicable to massive inserts from single session, but would it hold true for inserts from many parallel sessions? Would not partitioning reduce contention and such improve overall performance?
November 09, 2009 - 12:10 pm UTC
see above...
the answer to you is "it depends"
If you did not have massive contention, then introducing something that would reduce contention at the expense of figuring out where to put the row - would not do anything for you.
so, "it depends"
it could make it go faster
it could make it go slower
it could make it go neither faster nor slower
Thank you sir,
Fh.syed, November 02, 2009 - 10:52 pm UTC
November 09, 2009 - 12:45 pm UTC
you do know you are stealing that material - right?
Helena Marková, November 06, 2009 - 1:29 am UTC
Sub partition on different location
Arindam Mukherjee, November 06, 2009 - 7:44 am UTC
Sir,
I am new in RAC-ASM environment. In Oracle 10g, I partitioned one table and sub partitions are stored on different disks. In Oracle 10g on ASM, how can I store sub partitions on different disk as Disk group is used in ASM environment instead of single disk.
Please help me.
Regards,
November 11, 2009 - 1:43 pm UTC
well first, you wouldn't want to. the entire goal of striping here (and has been for years) is to make it so you don't have to think about that.
Unless you can tell me "the amount of IO - both read and write - is exactly the same on all three partitions - each gets exactly 1/nth of the read/write activity" - it would be a bad idea to do what you did anyway.
Use a disk group
Add to it as many disks as you can
we'll stripe across them - achieving even IO to all physical disk in the disk group
Striping makes it so we can think less hard.
does that mean you cannot do what you asked to do (please do not, it would be a bad idea)? No, you can - you would just put each physical disk into a separate disk group - but that would be a really bad idea.
i am confused.
Fh.syed, November 09, 2009 - 11:05 pm UTC
I'm stealing ? . Sir here is a great confusion. I did not add these books on 4shared.com .
I was browsing it for database related course material and found these two. I have already asked for your permission for the book which was given away for free.
my intention was to bring it to your knowledge that there are the stolen version of your book on a public sharing website www.4shared.com. And inquired you if they are also given away for free . IF NOT ! you can take proper action against it.
I am just an individual, having no rights what so ever to complain to the website on your behalf. You sir are the author , you can claim your right if they are stolen and published on website.
I did not expect you to stand up against me . I have been greatly disappointed by your unexpected followup
I have been a consistent reader of your site and will continue .
respect and regards
Fhsyed
November 11, 2009 - 3:00 pm UTC
you are using a site that has illegally posted copywritten material. You are stealing the content.
you asked if they were being given away, I responded "it would be stealing"
Now I understand
fh.syed, November 11, 2009 - 6:13 am UTC
No sir, i am not downloading it :) as it is indeed stealing.