CQL retrieval in `QueryExtractorDelegate` is CPU-intensive

[zhou-hao]

the getSql method execute every time.

spring-data-cassandra/spring-data-cassandra/src/main/java/org/springframework/data/cassandra/core/cql/ReactiveCqlTemplate.java

Line 306 in 889a3d6

return createFlux(action).onErrorMap(translateException("ReactiveSessionCallback", getCql(action)));

[mp911de]

Thanks for reporting the issue. We should use simple concatenation to avoid excessive formatting overhead on unknown statement types. Care to provide what type of Statement you're using? Maybe that's something we should consider additionally?

[zhou-hao]

spring-data-cassandra/spring-data-cassandra/src/main/java/org/springframework/data/cassandra/core/cql/ReactiveCqlTemplate.java

Lines 302 to 307 in 889a3d6

	public <T> Flux<T> execute(ReactiveSessionCallback<T> action) throws DataAccessException {
	Assert.notNull(action, "Callback object must not be null");
	return createFlux(action).onErrorMap(translateException("ReactiveSessionCallback", getCql(action)));
	}

The action parameter is a lambda expression, so ...

[mp911de]

It would make sense to replace the getEffectiveFetchSize(…) lambda with a proper class. Beyond that, if your ReactiveSessionCallback implements CqlProvider, then CQL extraction for the action would work as well.