(I'm assuming you are talking about column values here) > 1. Does specifying the type of a column affect performance other than the > cost of validating data as it is stored? > e.g. does it help compaction, etc? No. Validation is normally pretty light weight.
> From my reading of the docs the advantage is that the data will be validated > on write and that the various dev tools can deserialize into a human readable > form easily. Thats about it. > 2. Is there any impact to mixing static and dynamic columns in the same > column family? (Follow-up question: is this far outside of the designers' > intentions and thus unsafe?) I'm not sure what you mean by static and dynamic. > My mental model is that a column is just a column. It's possible to specify > some metadata about columns for validation and display but that's about it. > Is there something to change this model? That's my model too. Exceptions are secondary indexes and any data type requirements that CQL and associated db drivers need. I think some people take the approach of specifying the columns in the CF definition, this is just my personal approach. Cheers ----------------- Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 6/06/2012, at 4:30 AM, Edward Sargisson wrote: > Hi all, > A question has come up in our team about the performance impact of static vs > dynamic columns. We'd like to ask two questions: > > Quick background: We are using a custom app to write to Cassandra using > Hector. Production is Solaris and pre-prod is generally Centos. We're > currently on 0.7 but will be moving to 1.1 very shortly. > > 1. Does specifying the type of a column affect performance other than the > cost of validating data as it is stored? > e.g. does it help compaction, etc? > From my reading of the docs the advantage is that the data will be validated > on write and that the various dev tools can deserialize into a human readable > form easily. > > 2. Is there any impact to mixing static and dynamic columns in the same > column family? (Follow-up question: is this far outside of the designers' > intentions and thus unsafe?) > The docs seem to indicate that the designers think of static column families > and dynamic column families and *not* a mixture of the two. > > My mental model is that a column is just a column. It's possible to specify > some metadata about columns for validation and display but that's about it. > Is there something to change this model? > > Thanks in advance for any comments. > > Cheers, > Edward > > > -- > Edward Sargisson > senior java developer > Global Relay > > edward.sargis...@globalrelay.net > > > 866.484.6630 > New York | Chicago | Vancouver | London (+44.0800.032.9829) | Singapore > (+65.3158.1301) > > Global Relay Archive supports email, instant messaging, BlackBerry, > Bloomberg, Thomson Reuters, Pivot, YellowJacket, LinkedIn, Twitter, Facebook > and more. > > Ask about Global Relay Message — The Future of Collaboration in the Financial > Services World > > All email sent to or from this address will be retained by Global Relay’s > email archiving system. This message is intended only for the use of the > individual or entity to which it is addressed, and may contain information > that is privileged, confidential, and exempt from disclosure under applicable > law. Global Relay will not be liable for any compliance or technical > information provided herein. All trademarks are the property of their > respective owners.
