Hello,

I need to retrieve one random tuple from a big set of tuples returned by a
certain query. So my question is:

How can I find out the number of tuples returned by cursor, without actually
FETCHing ALL? (So I can MOVE then to that location and just FETCH 1).

Thanks,

I am not sure if I have understood your problem. Anyway here goes my advice.

If you want to select a random tupla, first of all you need to know how many of them there are. To achieve this write:

select count(*) from table where conditions;

Then get a random number between 1 and the number you got with the previous query. Execute the fetch command inside a loop and stop it when you reach the tupla you got with the random number.

A faster way is to ensure all tuplas got an unique id from 1 to ..., so when you get the random number, you can select the tupla with that id.

Hope this helps.