DeltaTimeTravelSpec¶

Creating Instance¶

DeltaTimeTravelSpec takes the following to be created:

• Timestamp
• Version
• Creation Source ID

DeltaTimeTravelSpec asserts that either version or timestamp is provided (and throws an AssertionError).

DeltaTimeTravelSpec is created when:

• DeltaAnalysis logical resolution rule is resolving RestoreTableStatement unary logical operator
• DeltaTimeTravelSpec utility is used to resolve a path
• DeltaDataSource utility is used to getTimeTravelVersion
• DeltaSource is requested to for the getStartingVersion

Version¶

version: Option[Long]

DeltaTimeTravelSpec can be given a version when created:

• DeltaAnalysis logical resolution rule is executed (to resolve a RestoreTableStatement)
• DeltaTimeTravelSpec utility is used to resolve path
• DeltaDataSource utility is used to getTimeTravelVersion

version is mutually exclusive with the timestamp (so only one can be specified).

Creation Source ID¶

DeltaTimeTravelSpec is given a Creation Source ID when created.

The Creation Source ID indicates the API used to time travel:

• Creation Source ID of the TimeTravel of RestoreTableStatement unary logical operator (when DeltaAnalysis logical resolution rule is executed)
• atSyntax.path for DeltaTimeTravelSpec
• dfReader for DeltaDataSource
• deltaSource for DeltaSource

Time Travel Patterns¶

DeltaTimeTravelSpec defines regular expressions for timestamp- and version-based time travel identifiers:

• Version URI: (path)@[vV](some numbers)
• Timestamp URI: (path)@(yyyyMMddHHmmssSSS)

Resolving Path¶

resolvePath(
  conf: SQLConf,
  identifier: String): (DeltaTimeTravelSpec, String)

resolvePath...FIXME

resolvePath is used when DeltaTableUtils utility is used to extractIfPathContainsTimeTravel.

getTimestamp¶

getTimestamp(
  timeZone: String): Timestamp

getTimestamp...FIXME

getTimestamp is used when DeltaTableUtils utility is used to resolveTimeTravelVersion.

isApplicable¶

isApplicable(
  conf: SQLConf,
  identifier: String): Boolean

isApplicable is true when all of the following hold:

• spark.databricks.delta.timeTravel.resolveOnIdentifier.enabled is true
• identifierContainsTimeTravel is true

isApplicable is used when DeltaTableUtils utility is used to extractIfPathContainsTimeTravel.

identifierContainsTimeTravel¶

identifierContainsTimeTravel(
  identifier: String): Boolean

identifierContainsTimeTravel is true when the given identifier is either timestamp or version time travel pattern.