how to get attribute in Sampler?

[1095071913]

I am developing a sampler to drop some traces that I don't need, e.g: redis ping/pong heartbeat connection.
But I found I can't get the attribute I need in Sampler.shouldSample method:
public class XxxSampler implements Sampler { SamplingResult shouldSample( Context parentContext, String traceId, String name, SpanKind spanKind, Attributes attributes, List<LinkData> parentLinks) { System.out.println("attributes.asMap() = " + attributes.asMap()); } }

I print all attributes, the output is:
attributes.asMap() = AttributesMap{data={db.system=redis, net.peer.name=localhost, net.transport=ip_tcp, net.peer.ip=127.0.0.1, net.peer.port=6379}, capacity=128, totalAddedValues=5}

there is no db.statement attribute, but there is db.statement attribute in final trace, jaeger snapshot:

I can't drop redis ping operation trace without db.statement attribute.

how can I get the missing attribute?any suggestion?

Related issues：#6251