Thanks DuyHai, I have a follow up question to #2. You mentioned ideally I would create a new table instead of mutating an existing one.
This strikes me as bad practice in the world of multi tenant systems. I don't want to create a table per customer. So I'm wondering if dynamically modifying the table is an accepted practice? -- about.me <http://about.me/markgreene> On Fri, Jun 13, 2014 at 2:54 PM, DuyHai Doan <doanduy...@gmail.com> wrote: > Hello Mark > > Dynamic columns, as you said, are perfectly supported by CQL3 via > clustering columns. And no, using collections for storing dynamic data is a > very bad idea if the cardinality is very high (>> 1000 elements) > > 1) Is using Thrift a valid approach in the era of CQL? --> Less and > less. Unless you are looking for extreme performance, you'd better off > choosing CQL3. The ease of programming and querying with CQL3 does worth > the small overhead in CPU > > 2) If CQL is the best practice, should I alter the schema at runtime when > I detect I need to do an schema mutation? --> Ideally you should not alter > schema but create a new table to adapt to your changing requirements. > > 3) If I utilize CQL collections, will Cassandra page the entire thing into > the heap? --> Of course. All collections and maps in Cassandra are eagerly > loaded entirely in memory on server side. That's why it is recommended to > limit their cardinality to ~ 1000 elements > > > > > On Fri, Jun 13, 2014 at 8:33 PM, Mark Greene <green...@gmail.com> wrote: > >> I'm looking for some best practices w/r/t supporting arbitrary columns. >> It seems from the docs I've read around CQL that they are supported in some >> capacity via collections but you can't exceed 64K in size. For my >> requirements that would cause problems. >> >> So my questions are: >> >> 1) Is using Thrift a valid approach in the era of CQL? >> >> 2) If CQL is the best practice, should I alter the schema at runtime >> when I detect I need to do an schema mutation? >> >> 3) If I utilize CQL collections, will Cassandra page the entire thing >> into the heap? >> >> My data model is akin to a CRM, arbitrary column definitions per customer. >> >> >> Cheers, >> Mark >> > >
