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