What do you mean by indexing? On Thu, Dec 9, 2010 at 7:30 PM, Sébastien Druon <sdr...@spotuse.com> wrote:
> Thanks a lot for the answer > > What about the indexing when adding a new element? Is it incremental? > > Thanks again > > > On 9 December 2010 14:38, David Boxenhorn <da...@lookin2.com> wrote: > >> How about a regular CF where keys are n...@n ? >> >> Then, getting a matrix row would be the same cost as getting a matrix >> column (N gets), and it would be very easy to add element N+1. >> >> >> On Thu, Dec 9, 2010 at 1:48 PM, Sébastien Druon <sdr...@spotuse.com>wrote: >> >>> Hello, >>> >>> For a specific case, we are thinking about representing a N to N >>> relationship with a NxN Matrix in Cassandra. >>> The relations will be only between a subset of elements, so the Matrix >>> will mostly contain empty elements. >>> >>> We have a set of questions concerning this: >>> - what is the best way to represent this matrix? what would have the best >>> performance in reading? in writing? >>> . a super column family with n column families, with n columns each >>> . a column family with n columns and n lines >>> >>> In the second case, we would need to extract 2 kinds of information: >>> - all the relations for a line: this should be no specific problem; >>> - all the relations for a column: in that case we would need an index for >>> the columns, right? and then get all the lines where the value of the column >>> in question is not null... is it the correct way to do? >>> When using indexes, say we want to add another element N+1. What impact >>> in terms of time would it have on the indexation job? >>> >>> Thanks a lot for the answers, >>> >>> Best regards, >>> >>> Sébastien Druon >>> >> >> >
