low-latency

Describe the bug

QuestDB throws an error if my query returns 0 rows when using SAMPLE BY. It works fine and responds 0 row found without SAMPLE BY.

My query (I run it on QuestDB web console directly)

SELECT ts, pair, side, round(nsum(size)) as size
FROM liquidations
WHERE pair = 'ETC-USDT-PERP' and side = 'sell' and size > 500
SAMPLE BY 1m
ALIGN TO CALENDAR WITH OFFSET '00:00'

Avoid controlling endless loop with exception in loadAnonymousClasses, e.g. by extracting loading class to the method:

  private boolean tryLoadClass(String innerClassName) {
        try {
            parent.loadClass(innerClassName);
        } catch (ClassNotFoundException ex) {
            return false;
        }
        return true;
    }

https://sonarcloud.io/project

For example, given a simple pipeline such as:

Pipeline p = Pipeline.create();
p.readFrom(TestSources.items("the", "quick", "brown", "fox"))
 .aggregate(aggregator)
 .writeTo(Sinks.logger());

I'd like aggregator to be something requiring a non-serialisable dependency to do its work.

I know I can do this:

Pipeline p = Pipeline.create();
p.readFrom(TestSource