On 2008-02-07 16:46, Carsten Haese wrote: > On Thu, 2008-02-07 at 16:33 +0100, M.-A. Lemburg wrote: >> mxODBC has support for named cursors that you can later >> use for positioned updates. > > Since we're on the topic of shameless plugs, InformixDB has this > feature, too :) > >> However, it's usually better to do updates in the classical >> way, ie. by referencing a primary key. > > That depends on the notion of "better". It's entirely possible that a > "WHERE CURRENT OF <cursor>" clause finds the row in question faster than > even an indexed access using a primary key could. If you're processing a > single row, I would agree that using an update cursor is overkill, but > if you're processing a large number of rows, using an update cursor > might be beneficial.
Agreed. This approach is also very useful if you have to do extra analysis of the rows in question *outside* the database, before selecting them for update. -- Marc-Andre Lemburg eGenix.com Professional Python Services directly from the Source (#1, Feb 07 2008) >>> Python/Zope Consulting and Support ... http://www.egenix.com/ >>> mxODBC.Zope.Database.Adapter ... http://zope.egenix.com/ >>> mxODBC, mxDateTime, mxTextTools ... http://python.egenix.com/ ________________________________________________________________________ :::: Try mxODBC.Zope.DA for Windows,Linux,Solaris,MacOSX for free ! :::: eGenix.com Software, Skills and Services GmbH Pastor-Loeh-Str.48 D-40764 Langenfeld, Germany. CEO Dipl.-Math. Marc-Andre Lemburg Registered at Amtsgericht Duesseldorf: HRB 46611 -- http://mail.python.org/mailman/listinfo/python-list
