StAck, Just because FB does something doesn't mean its necessarily a good idea for others to do the same. FB designs specifically for their needs and their use cases may not match those of others.
To your point though, I agree that Ted's number of 3 is more of a rule of thumb and not a hard and fast number. I think that the wording in that section should be changed. (I may take a stab at it later today...) In our HBase course, I teach an example of an Order entry system. (Order, Pick, Ship, Invoice) There are 4 column families in that example. To your point, in the use cases, the CFs are usually used in an atomic fashion. When I do a pick slip, I don't need to constantly reference the order, except when I initially create the Pick Slip(s). The larger question in terms of design, should you use a CF to segment your data if you're constantly pulling data from both CFs in your main use case, or should they be part of the same table? -Mike On Apr 7, 2013, at 5:45 PM, Stack <st...@duboce.net> wrote: > On Sun, Apr 7, 2013 at 3:27 PM, Ted Yu <yuzhih...@gmail.com> wrote: > >> From http://hbase.apache.org/book.html#number.of.cfs : >> >> HBase currently does not do well with anything above two or three column >> families so keep the number of column families in your schema low. >> > > We should add more to that section. FB run w/ ~15 and purportedly it works > with appropriate write and query pattern. > St.Ack
