10 ms·
Cool! I briefly skimmed through the paper, and it seems like one of the advertised features is JOINs across chunks. How efficient is it? How do you figure out
by elvinyung 10y ago
Cool!
I briefly skimmed through the paper, and it seems like one of the advertised features is JOINs across chunks. How efficient is it? How do you figure out what join algorithms to use?
- cevian 10y agoHi elvinyung, we have three cases (1) chunks from the same hypertable are effectively UNIONized (not JOIN) when collecting results. (2) If JOINING 2 hypertables we have an upcoming feature of allowing the user to specify two hypertables as colocated, which will put chunks for same time/space partition on same node. Otherwise we will transfer the smaller of the chunks across the network (pretty much the usual join logic. (3) For joining a hypertable with a regular table, the regular tables is fetched if it does not exists locally. We will have an option to materialize regular tables across nodes (great if the table is small and read-only).