ECL - HPCC Testing Roxie query

Question

I'm trying to write a Roxie query using ECL language. Is there a way to write and test the code without constantly publishing the query?

Answer 1

I am assuming that you are only seeking to avoid the extra UI-oriented steps in publishing a query (switching back and forth between ECL Watch and your dev environment, for instance). You can make testing on roxie relatively painless with some build scripting and REST calls.

In HPCC, roxie and hthor are similar from an execution and runtime environment viewpoint. Their tactical execution strategies are different (roxie handles queries in OS threads, hthor handles them by forking child processes), but the rule of thumb is that if you can get code to work well in hthor then it will probably work well in roxie.

You can leverage that similarity during development. Rather than publishing the query to roxie, testing, tearing down the query, and repeating all that, you can simply submit the job to hthor (much like you would do for a thor job). You would have to hardcode some test values that would normally be parameters for the roxie query, but that is simple enough.

An additional bonus to using hthor is that it is the only engine that supports any kind of step-by-step debugging. That can be a hit-or-miss proposition, though, depending on the version of HPCC you are executing against and you did not mention that. Even if you don't use the debugger, hthor's execution graphs at least show details on a specific query's data flows such as record counts at each step (roxie shows the graph, but there is no detailed information on individual queries).