Hi Cassandra Users, I am considering Cassandra as the main data store. Just a quick description of the entity structure that we are looking at to store/design schema for. So we have 3 entities A,B and C. A has one to many relationship with B and similar is true for B and C. Hence this gives us a tree like structure with A as a root. To store this structure in the Cassandra I am looking at the following col family schema design.
Col Family : For storing A Id of A - Key Date - Indexed Byte format of A object Col Family : For storing B Id of B - Key Date - Indexed field Id of A to which B belongs - Indexed Byte format of B object Col Family : For storing C Id of C - Key Date - Indexed field Id of A to which C belongs - Indexed Id of B to which C belongs - Indexed Byte format of C object Maintaining an index on date because caches are supposed to be preloaded with say 3 days worth of data. Now the questions are 1. Are the indexes local? i.e if node 1 holds say 10 keys that will only have indexes for theses 10 keys. In short - interested in knowing how is the index partitioned? n Just to appreciate the concern I have consider the case where we receive 100 keys and we have 10 Cassandra nodes. Assuming even distribution of 10 keys each node. Will there be 10 partitions of the index on 10 different nodes - only of the keys it owns? 2. Opinion about the schema design above. To list down the use cases - n Preload the processes on start up with 3 days of data. (The data store should hold data which dates as back as 3 years) n Given Id of A get all the B's and C's of the tree. Hoping to hear soon. Thanks and Regards, Dushyant -------------------------------------------------------------------------- NOTICE: Morgan Stanley is not acting as a municipal advisor and the opinions or views contained herein are not intended to be, and do not constitute, advice within the meaning of Section 975 of the Dodd-Frank Wall Street Reform and Consumer Protection Act. If you have received this communication in error, please destroy all electronic and paper copies and notify the sender immediately. Mistransmission is not intended to waive confidentiality or privilege. Morgan Stanley reserves the right, to the extent permitted under applicable law, to monitor electronic communications. This message is subject to terms available at the following link: http://www.morganstanley.com/disclaimers. If you cannot access these links, please notify us by reply message and we will send the contents to you. By messaging with Morgan Stanley you consent to the foregoing.
