Question about 'iterable cursors'

From	"Frank Millman" <frank@chagford.com>
Subject	Question about 'iterable cursors'
Date	2011-11-06 10:54 +0200
Newsgroups	comp.lang.python
Message-ID	<mailman.2460.1320569710.27778.python-list@python.org> (permalink)

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Hi all

I am using a few DB_API adaptors - ceODBC for Sql Server, psycopg2 for 
PostgreSQL, and sqlite3 for sqlite3.

They all offer the feature that if a cursor executes a SELECT, the cursor 
returns an iterator which can be used to fetch one row at a time. I have 
been using this feature for a while and it seems like a 'good thing'.

Now I am not so sure. I am using a connection pool to maintain connections 
to the database. A principle I am following is that a connection must be 
returned quickly, so that it is available for reuse.

I have been happily returning the connection, but keeping the cursor open 
while processing the rows selected. I now realise that this is dangerous. 
Therefore I have changed my system to execute fetchall() on the cursor 
before returning the connection. This obviously loses the benefit of the 
iterator.

I would appreciate confirmation that my thinking is correct on this issue. 
Or is there any way that I can have my cake and eat it?

Thanks

Frank Millman

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Question about 'iterable cursors' "Frank Millman" <frank@chagford.com> - 2011-11-06 10:54 +0200
  Re: Question about 'iterable cursors' Alain Ketterlin <alain@dpt-info.u-strasbg.fr> - 2011-11-06 10:16 +0100
    Re: Question about 'iterable cursors' "Frank Millman" <frank@chagford.com> - 2011-11-06 11:39 +0200
    Re: Question about 'iterable cursors' Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2011-11-06 12:04 -0800
      Re: Question about 'iterable cursors' John Nagle <nagle@animats.com> - 2011-11-06 22:04 -0800
        Re: Question about 'iterable cursors' Lie Ryan <lie.1296@gmail.com> - 2011-11-08 16:29 +1100

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