yupeng9 commented on pull request #6530: URL: https://github.com/apache/incubator-pinot/pull/6530#issuecomment-772225363
> > > LGTM. > > > (Not related to this PR) For easier management of the cluster, I would recommend having a separate tenant for the dimension table so that dimension table can be shared by multiple tenants. You can configure the server with multiple tags, and the server can belong to multiple tenants. > > > > > > Since this is the first time we have queries across tables, I think it's a good time to discuss the policy. There are two options: join tables within the tenant, and join tables across tenants. Personally I prefer a default constraint that the tables to join are within the same tenant for better isolation. But given the broadcast join nature, the dimension table is in fact copied to all tenants. Nevertheless, I feel it's good to have this high-level consideration. > > Currently there is no broadcast happening right? I think we are on the same page: the dimension table is distributed (i.e. broadcasted) to all servers, though not at the query time. > > I thought the design was to have full dimension table colocated with fact table servers so that each server does a local join with part of fact table and full dimension table. > > For the eventual implementation of fact-dimension using broadcast, I don't think we should have cross tenant joins since the data movement will take longer. We can probably allow it but the recommendation should probably be joins within the same tenant. Joins across tenant essentially become a cross cluster join which is likely to be expensive (but depends on the topology I guess) ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For additional commands, e-mail: commits-h...@pinot.apache.org
