Skip to content

DeltaTableValueFunctions

supportedFnNames

DeltaTableValueFunctions defines the following table-valued functions:

getTableValueFunctionInjection

type TableFunctionDescription =
    (FunctionIdentifier, ExpressionInfo, TableFunctionRegistry.TableFunctionBuilder)
getTableValueFunctionInjection(
    fnName: String): TableFunctionDescription

getTableValueFunctionInjection...FIXME

getTableValueFunctionInjection is used when:

resolveChangesTableValueFunctions

resolveChangesTableValueFunctions(
  session: SparkSession,
  fnName: String,
  args: Seq[Expression]): LogicalPlan

resolveChangesTableValueFunctions extracts the following values of the CDF options (from the given args expressions):

  • startingVersion or startingTimestamp
  • endingVersion or endingTimestamp

resolveChangesTableValueFunctions defines the following option:

Option Value
readChangeFeed true

For table_changes, resolveChangesTableValueFunctions requests the SessionCatalog (Spark SQL) for the table metadata.

resolveChangesTableValueFunctions creates a DeltaTableV2 for the table path (from the SessionCatalog or given explicitly for table_changes_by_path) and the CDF options.

resolveChangesTableValueFunctions requests the DeltaTableV2 for a BaseRelation to create a LogicalRelation (Spark SQL).

Non-Streaming LogicalRelation

resolveChangesTableValueFunctions creates a non-streaming LogicalRelation.

resolveChangesTableValueFunctions is used when: