CachedDS — Cached Delta State¶
CachedDS is used when StateCache is requested to cacheDS.
Creating Instance¶
CachedDS takes the following to be created:
-
Dataset[A] - Name
CachedDS is created when:
StateCacheis requested to cacheDS
cachedDs¶
cachedDs: Option[DatasetRefCache[Row]]
Note
cachedDs is a value so initialized immediately when CachedDS is created.
cachedDs requests the Dataset for an RDD[InternalRow].
cachedDs associates the RDD with the name and marks it to be persist (on the first action).
cachedDs adds the RDD to the cached registry.
Note
CachedDS is an internal class of StateCache and has access to its internals.
cachedDs is used when:
CachedDSis requested to getDF
getDS¶
getDS: Dataset[A]
getDS gets the cached DataFrame and converts the rows to A type.
getDS is used when:
Snapshotis requested for the stateDS DatasetDeltaSourceSnapshotis requested for the initialFiles DatasetDataSkippingReaderBaseis requested for the withStatsInternal Dataset