Hello I am looking at “monitoring/tracing” the resultset execution tree to observe the tuples/records as they propagate up the tree - specifically the calls to getNextRowCore() in BulkTableScanResultSet, NestedLoopJoinResultSet, etc. For aggregations I am looking at using the SortObserver type interface.
There does not appear to be much in the way of metadata available (at least I have not found it) in the execution tree? I am traversing the AST tree after bind/generate to pick up some of the metadata. This is easy enough when a column is directly associated with a base table, but, is getting hacky otherwise. Is there a better solution? Putting something in during the generate phase looks like a daunting task! I realise I can use the toXML/childrenToXML interface to walk the execution tree, but there does not appear to be much in the way of metadata here. I suppose what I am asking is, is there a direct link from the org.apache.derby.impl.sql.execute.ResultSet hierarchy back to the org.apache.derby.impl.sql.compile.ResultSetNode hierarchy? Thanks, Paul.
