[Ruby-DBI-devel] Problem with 'too many open cursors'

[Brian C. <B.C...@po...>]

While running some code which does a lot of db.select_one and db.execute
calls, I was getting Oracle errors saying 'too many open cursors' - although
I had only a single DBI handle open.

Digging around, I found that:

- I should have been using db.do() not db.execute(); the latter returns a
  sth which I was never using, so Oracle cursors accumulate until garbage
  collection kicks in

- db.select_one doesn't seem to call finish() to free up the cursor. I think
  the attached one-line patch should fix that.

However, I'm not sure if there are any knock-on effects. The default
implementation of DBI::BaseStatement.finish says

  def finish
    raise NotImplementedError
  end

Perhaps it would be safer to make this a null operation?

I'm also not sure about 'select_all'. It calls 'fetch_all', but is that
guaranteed to free up the cursor after it has finished?

Regards,

Brian.