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This looks very interesting, however I'm concerned about some of the implementation details... 1. It mentions using secondary indexes - its my understanding th
by cipherzero 10y ago
This looks very interesting, however I'm concerned about some of the implementation details...
1. It mentions using secondary indexes - its my understanding thats a huge no-no, as they have to hit the whole cluster
2. Uses "lightweight" transactions - also another perf hit, as lightweight transactions have (anecdotally) a 6x slowdown...
I like the idea but I'm curious if these are issues and whether these uses are something the author is looking to replace...
Very interesting idea though!
(CoAuthor of cassieq here so these were things we had to learn about.)
- ddorian43 10y agoindexes are together with the data. the partition key becomes the _routing key, so you can always search 1, x, or all nodes depending on your _routing value lightweight transactions are only used on schema-changes (which are/should-be rare)
- cipherzero 10y agoAwesome, i watched the demo video... i will be trying this. Thanks for the info on lightweight transactions, sounds like the perfect use then! As for the indexes - are they standard Cassandra secondary indexes? "Custom secondary indexes" - does that mean that it just looks like a secondary index, but is actually backed by Elastic search?
- ddorian43 10y agoCassandra offers a way to create your own custom-secondary-index. In this case, the secondary-index is backed by elasticsearch/lucene. Though you can't query it from cassandra yet. You have to use the elastic-search rest-api.
- cipherzero 10y agoThats ridiculously beautiful! Thank you!