> Does it mean that the popular use case is when we need to update multiple > column families using the same key? Yes.
> Shouldn’t we design our space in such a way that those columns live in the > same column family? Design a model where the data for common queries is stored in one row+cf. You can also take into consideration the workload. e.g. things are are updated frequently often live together, things that are updated infrequently often live together. cheers ----------------- Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 6/07/2012, at 3:16 AM, Leonid Ilyevsky wrote: > I actually found an answer to my first question at > http://wiki.apache.org/cassandra/API. So I got it wrong: actually the outer > key is the key in the table, and the inner key is the table name (this was > somewhat counter-intuitive). Does it mean that the popular use case is when > we need to update multiple column families using the same key? Shouldn’t we > design our space in such a way that those columns live in the same column > family? > > From: Leonid Ilyevsky [mailto:lilyev...@mooncapital.com] > Sent: Thursday, July 05, 2012 10:39 AM > To: 'user@cassandra.apache.org' > Subject: batch_mutate > > My current way of inserting rows one by one is too slow (I use cql3 prepared > statements) , so I want to try batch_mutate. > > Could anybody give me more details about the interface? In the javadoc it > says: > > public > voidbatch_mutate(java.util.Map<java.nio.ByteBuffer,java.util.Map<java.lang.String,java.util.List<Mutation>>> > mutation_map, > ConsistencyLevel consistency_level) > throws InvalidRequestException, > UnavailableException, > TimedOutException, > org.apache.thrift.TException > Description copied from interface: Cassandra.Iface > Mutate many columns or super columns for many row keys. See also: Mutation. > mutation_map maps key to column family to a list of Mutation objects to take > place at that scope. * > > > I need to understand the meaning of the elements of mutation_map parameter. > My guess is, the key in the outer map is columnfamily name, is this correct? > The key in the inner map is, probably, a key to the columnfamily (it is > somewhat confusing that it is String while the outer key is ByteBuffer, I > wonder what is the rational). If this is correct, how should I do it if my > key is a composite one. Does anybody have an example? > > Thanks, > > Leonid > > This email, along with any attachments, is confidential and may be legally > privileged or otherwise protected from disclosure. Any unauthorized > dissemination, copying or use of the contents of this email is strictly > prohibited and may be in violation of law. If you are not the intended > recipient, any disclosure, copying, forwarding or distribution of this email > is strictly prohibited and this email and any attachments should be deleted > immediately. This email and any attachments do not constitute an offer to > sell or a solicitation of an offer to purchase any interest in any investment > vehicle sponsored by Moon Capital Management LP (“Moon Capital”). Moon > Capital does not provide legal, accounting or tax advice. Any statement > regarding legal, accounting or tax matters was not intended or written to be > relied upon by any person as advice. Moon Capital does not waive > confidentiality or privilege as a result of this email. > > This email, along with any attachments, is confidential and may be legally > privileged or otherwise protected from disclosure. Any unauthorized > dissemination, copying or use of the contents of this email is strictly > prohibited and may be in violation of law. If you are not the intended > recipient, any disclosure, copying, forwarding or distribution of this email > is strictly prohibited and this email and any attachments should be deleted > immediately. This email and any attachments do not constitute an offer to > sell or a solicitation of an offer to purchase any interest in any investment > vehicle sponsored by Moon Capital Management LP (“Moon Capital”). Moon > Capital does not provide legal, accounting or tax advice. Any statement > regarding legal, accounting or tax matters was not intended or written to be > relied upon by any person as advice. Moon Capital does not waive > confidentiality or privilege as a result of this email.
