On Mon, Jan 18, 2016 at 2:37 PM, drum.lu...@gmail.com <drum.lu...@gmail.com> wrote:
> I've created a function that allows me to do an huge update. > > But I need to limit this function. I need to do 50k rows (example) and > then stop it. After that I need to continue from the rows that I've > stopped... I'll have to modify the call function *select batch_number()* as > well. > > How can I do that? Using for? > It is customary to restrict emails to a single list or at least make others aware when you do have a legitmate need to cross-post. Specifically your post on -admin <“Break” in plpgsql Function - PostgreSQL 9.2> Yes, it didn't belong on -admin in the first place but posting it here with a different title and not indicating on either thread that the other exists and/or is the valid one just makes it harder for others to follow along. As for your general question I try to approach this problem in the following manner: SELECT however many of something that you need (FOR UPDATE) UPDATE those selected to indicate that they have been seen PROCESS them as needed repeat step 1 until it returns no records It doesn't always work - and given a sufficiently large number of records it may be unadvisable - but it is set-oriented which is generally a plus in SQL. The other way to assign batches is to use the integer modulus operator (e.g., 10 % 3 = 1 : read 3 *remainder of 1*) or integer division (10 / 3 = 3) to derive the batch number based upon an attribute of the data itself as opposed to its order of appearance in a result set. David J.
