Обсуждение: Further details on cursors.

I am running into an odd problem when fetching from multiple cursors in Perl. However, I do not feel knowledgeable enough to ask an intelligent question.
Can you in the community direct me at some deeper documentation. Perhaps a developers guide (for Postgres itself), that might discuss the internal handling
of  cursors, queries prepared within the cursor and what happens when the end of a block of fetched data is reached.