We’ve been looking at running test queries on a Qserv installation of our UKIDSS data. In our data model we use pre-calculated neighbour tables to join our observations internally and with external data sets. eg we have a source, detection and neighbour table.
For our Qserv test we have each table in a separate director database and the source and detection tables are split up into identical chunks.
If I try and do a query like
select blah from dbs.source as s, dbd.detection as d, dbm.neighbour as n
where s.sourceID=n.sourceID and d.detectionID=n.detectionID
ERROR 4110 (Proxy): Query processing error: QI=?: Failed to instantiate
query: AnalysisError:Query involves partitioned table joins that Qserv does
not know how to evaluate using only partition-local data
the query can be run by adding for example
scisql_angSep(s.ra, s.decl, d.ra, d.decl) < 0.016
but this I believe is then effectively not making use of the pre-existing lookups in the neighbour table and doing lots of trig.
Does anyone know of a work around so that the query uses the neighbour table for efficient joining.