Question

I would like to perform a certain selection which (as I tested in sqldeveloper) will retrieve a very large amount of data (~350,000 rows). Eventually, I would like to write these rows to a file.

I intend to write a PERL code that does it and I was wondering if there was a way to retrieve one row at a time, write it to my output file and continue to the next row.

That is, I would like to get the same result as my original select but in smaller chunks.

Thanks!!!

Answer 1

If you think you can pay executing your query many times, you can use

SELECT .... FROM ...
WHERE ....
LIMIT 0, 100 // index_from, amount

first time, adding amount to index next time

SELECT .... FROM ...
WHERE ....
LIMIT 100, 100

You could use LIMIT 0,1 to get one record at a time, but you have 350k records… it’s crazy!!