[DB-SIG] Clarification of cursor.arraysize
carsten at uniqsys.com
Tue Dec 19 01:26:46 CET 2006
On Mon, 2006-12-18 at 16:56 -0500, Art Protin wrote:
> Dear folks,
> I find yet again that I am confused by what I read in pep-0249.
> This time it is the last line describing the attribute of cursor objects
> named .arraysize (I quote here both paragraphs):
> This read/write attribute specifies the number of rows to
> fetch at a time with fetchmany(). It defaults to 1 meaning
> to fetch a single row at a time.
> Implementations must observe this value with respect to
> the fetchmany() method, but are free to interact with the
> database a single row at a time. It may also be used in
> the implementation of executemany().
> I fail to grasp how .arraysize could have any bearing on .executemany()
> or for that matter any operation other than fetchmany(). Thus I find I
> must request aid in understanding what the intent is here - HELP, please.
It says "It *may* be used in the implementation of executemany()." I
imagine this would be useful for a database API that allows passing
parameters in bulk. You're free to implement executemany() without
referring to arraysize if there is no advantage in referring to
> While I am bothering you good people with my silly questions, I
> might just as well tack on another: if one invokes .executemany with a
> seq_of_parameters that is empty (like
> a_cursor.executemany(SQL, )
> ) shouldn't the interface module execute the query zero times, ie, not
> execute the query at all?
Yes, executemany() with an empty sequence is a no-op.
Carsten Haese | Phone: (419) 861-3331
Software Engineer | Direct Line: (419) 794-2531
Unique Systems, Inc. | FAX: (419) 893-2840
1687 Woodlands Drive | Cell: (419) 343-7045
Maumee, OH 43537 | Email: carsten at uniqsys.com
More information about the DB-SIG