No, the slice semantics are "give me whatever happens to exist between start and end." It's valid for the answer to be "nothing."
On Thu, Jul 28, 2011 at 6:55 AM, David Allsopp <dnalls...@gmail.com> wrote: > If I try to retrieve a column that is not present, using get(), then I'll > get a NotFoundException. > > If (for efficiency's sake) I try to retrieve several named columns using > get_slice, with a column_names predicate (i.e. a list of columns) then I > won't get the exception if one of those columns is missing, I think? > > This seems inconsistent - would it make sense for get_slice to throw the > exception too, or perhaps have an option to require all columns to be > present? > > > The reason this came up is that I write and read with CL.ONE, and retry at > the client side in case of (very occasional) failures, with the aim of > improving availability and performance by avoiding CL.QUORUM etc. > This is easy in the get() case - I can just retry a few times if I get a > NotFoundException. I normally only need to retry once, in less than 0.1% of > cases. > > For the get_slice case I'd need to retrieve all the columns again (might be > wasteful) or check which ones were returned and form a new request (seems > overly complex) or give up using get_slice and just use individual get() > calls (seems inefficient). > > See also https://issues.apache.org/jira/browse/CASSANDRA-518 > > Thanks, > > David. > -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of DataStax, the source for professional Cassandra support http://www.datastax.com
