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:
StateCache
is 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:
CachedDS
is requested to getDF
getDS¶
getDS: Dataset[A]
getDS
gets the cached DataFrame and converts the rows to A
type.
getDS
is used when:
Snapshot
is requested for the stateDS DatasetDeltaSourceSnapshot
is requested for the initialFiles DatasetDataSkippingReaderBase
is requested for the withStatsInternal Dataset