Class MutableTupleSchema.ColumnHandle
java.lang.Object
org.apache.drill.exec.physical.impl.scan.v3.schema.MutableTupleSchema.ColumnHandle
- Enclosing class:
- MutableTupleSchema
Holder for a column to allow inserting and replacing columns within
the top-level project list. Changes to the column within the holder
must go through the tuple itself so we can track schema versions.
Tracks the resolution status of each individual column as
described for ScanSchemaTracker
. Models a column throughout the
projection lifecycle. Columns evolve from unresolved to resolved at
different times. Columns are either implicit (defined by the framework)
or normal (defined by the reader). Columns can be defined by the
planner (via a defined schema), partially defined (via a provided
schema), or discovered by the reader. Regardless of the path
to definition, by the time the first batch is delivered downstream,
each column has an output schema which describes the data.
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptioncolumn()
boolean
void
markImplicit
(ImplicitColumnMarker marker) name()
void
setIndex
(int index) toString()