Re: reading the oracle files

<liorlew_at_gmail.com> wrote in message
news:1120806605.263443.126960_at_o13g2000cwo.googlegroups.com...
> Hello,
>
> I have recently been asked to extract a very large volume of Data from
> an oracle DB (something like 40,000,000 records).
>
> I know that there is some way to open the oracle files directly and
> extracting the Data from there (uploading). this will do it must
> faster.
>
> does any one know how to do it? I am using c and c++
>
> thanks,
>
> Lior
>

I have a program that reads the datafiles directly. It is used to find corruption. (I got it from an Oracle employee.) But I doubt it would read the information faster than Oracle does. Oracle does have a service (costs a minimum of $10,000 a couple of years ago) to extract the data from the Oracle files. However, I think it does this by running a copy of the Oracle engine and extracting the information to sql loader files (1 per table).

I do not think that you will read the data any faster out of the database any faster than Oracle does. In extracting a mass of data you should use the array interface and bind variables. (See application programers guide) The array interface allows you to fetch many rows at one time. (try 100 or 1,000 rows at a time) You can use C/C++, Java, VB, and many other languages to use the array interface.

I saw that you are trying to optimize the query. That is good, but how long does it take to parse the query (execute and fetch 1 row). How long does it take to get the rest of the result set. It the 1st fetch takes a long time then optimizing the query would be valuable. If the 1st fetch is quick then the array interface would help a lot. (It will help in any event.) You need to find where your bottle neck is and address the highest time sink first. Jim Received on Fri Jul 08 2005 - 10:10:28 CDT