Internally a multiget just turned into a series of single row gets. There is no seek and partial scan such as you may see when reading from the clustered index in a RDBMS.
Unless you have a performance problem and you've tried other things I'd put this idea of the back burner. There are many other factors that impact read performance, and OOP requires a lot more care than RP. Aaron On 21 Mar 2011, at 11:36, buddhasystem wrote: > Aaron, thanks for chiming in. > > I'm doing what you said, i.e. all data for a single object (which is quite > lean with about 100 attributes 10 bytes each) just goes into a single > column, as opposed to the previous version of my application, which had all > attributes of each small object mapped to individual columns. > > So yes, I perhaps considered having 100 objects in a single column but that > is suboptimal for many reasons (hard to add object later). > > My reference to OOP was this -- if I was sticking with the original design, > it could have been advantageous to have OOP since statistically it's likely > that requests for objects are often serial, e.g. often people don't query > for just one object with id=123, but for a series like id=[123..145]. If I > bunch these into rows containing 100 objects each, that promises some > efficiency right there, as I read one row as opposed to say 50. > > > > > aaron morton wrote: >> >> I'd collapse all the data for a single object into a single column, not >> sure about storing 100 objects in a single column though. >> >> Have you considered any concurrency issues ? e.g. multiple threads / >> processes wanting to update different objects in the same group of 100? >> >> Dont understand your reference to the OOP in the context of a reading 100 >> columns from a row. >> >> Aaron >> >> >> On 19 Mar 2011, at 16:22, buddhasystem wrote: >> >> > As I'm working on this further, I want to understand this: >> > >> > Is it advantageous to flatten data in blocks (strings) each >> containing a >> > series of objects, if I know that a serial object read is often >> likely, but >> > don't want to resort to OPP? I worked out the optimal granularity, it >> seems. >> > Is it better to read a serialized single column with 100 objects than >> a row >> > consisting of a hundred columns each modeling an object? >> > >> > -- >> > View this message in context: >> http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Reading-whole-row-vs-a-range-of-columns-pycassa-tp6186518p6186782.html >> > Sent from the cassandra-u...@incubator.apache.org mailing list >> archive at Nabble.com. >> > > > -- > View this message in context: > http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Reading-whole-row-vs-a-range-of-columns-pycassa-tp6186518p6190639.html > Sent from the cassandra-u...@incubator.apache.org mailing list archive at > Nabble.com.
