THPDFLoadedStreamCacheInfo Record
LazyStreamCount, SourceBackedStreamCount, MemoryMaterializedStreamCount, and DiskMaterializedStreamCount report stream residency, with DiskMaterializedBytes measuring spilled volume
CompressedSpillLogicalBytes, CompressedSpillPhysicalBytes and CompressedSpillBlockCount describe the compressed spill store
SpillAsyncWriteBatchCount, SpillAsyncWriteBlockCount, SpillProducerWaitCount and SpillPeakQueuedBytes report asynchronous spill write activity