ColumnState (Drill : 1.20.3 API)

java.lang.Object
- org.apache.drill.exec.physical.resultSet.impl.ColumnState

Direct Known Subclasses:

ColumnState.BaseContainerColumnState, ColumnState.PrimitiveColumnState
```
public abstract class ColumnState
extends Object
```
Represents the write-time state for a column including the writer and the (optional) backing vector. Implements per-column operations such as vector overflow. If a column is a (possibly repeated) map, then the column state will hold a tuple state.
If a column is not projected, then the writer exists (to make life easier for the reader), but there will be no vector backing the writer.
Different columns need different kinds of vectors: a data vector, possibly an offset vector, or even a non-existent vector. The VectorState class abstracts out these differences.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`ColumnState.BaseContainerColumnState`
`static class`	`ColumnState.PrimitiveColumnState` Primitive (non-map) column state.
`protected static class`	`ColumnState.State` Columns move through various lifecycle states as identified by this enum.

Field Summary

Fields
Modifier and Type	Field and Description
`protected int`	`addVersion`
`protected int`	`cardinality` Cardinality of the value itself.
`protected org.apache.drill.exec.physical.resultSet.impl.LoaderInternals`	`loader`
`protected int`	`outputIndex`
`protected ColumnState.State`	`state`
`protected VectorState`	`vectorState`
`protected AbstractObjectWriter`	`writer`

Constructor Summary

Constructors
Constructor and Description
`ColumnState(org.apache.drill.exec.physical.resultSet.impl.LoaderInternals loader, AbstractObjectWriter writer, VectorState vectorState)`

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`allocateVectors()`
`void`	`buildOutput(TupleState tupleState)`
`void`	`close()`
`void`	`dump(HierarchicalFormatter format)`
`void`	`harvestWithLookAhead()` Writing of a row batch is complete.
`int`	`innerCardinality()`
`boolean`	`isProjected()`
`int`	`outerCardinality()`
`abstract ColumnMetadata`	`outputSchema()`
`void`	`rollover()` A column within the row batch overflowed.
`ColumnMetadata`	`schema()`
`void`	`startBatch(boolean schemaOnly)` Prepare the column for a new row batch after overflow on the previous batch.
`void`	`updateCardinality(int cardinality)`
`<T extends ValueVector> T`	`vector()`
`VectorState`	`vectorState()`
`AbstractObjectWriter`	`writer()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - loader
```
protected final org.apache.drill.exec.physical.resultSet.impl.LoaderInternals loader
```
  - addVersion
```
protected final int addVersion
```
  - vectorState
```
protected final VectorState vectorState
```
  - state
```
protected ColumnState.State state
```
  - writer
```
protected AbstractObjectWriter writer
```
  - cardinality
```
protected int cardinality
```
    Cardinality of the value itself. If this is an array, then this is the number of arrays. A separate number, the inner cardinality, is computed as the outer cardinality times the expected array count (from metadata.) The inner cardinality is the total number of array items in the vector.
  - outputIndex
```
protected int outputIndex
```
- Constructor Detail
  - ColumnState
```
public ColumnState(org.apache.drill.exec.physical.resultSet.impl.LoaderInternals loader,
                   AbstractObjectWriter writer,
                   VectorState vectorState)
```
- Method Detail
  - writer
```
public AbstractObjectWriter writer()
```
  - schema
```
public ColumnMetadata schema()
```
  - vectorState
```
public VectorState vectorState()
```
  - vector
```
public <T extends ValueVector> T vector()
```
  - allocateVectors
```
public void allocateVectors()
```
  - startBatch
```
public void startBatch(boolean schemaOnly)
```
    Prepare the column for a new row batch after overflow on the previous batch. Restore the look-ahead buffer to the active vector so we start writing where we left off.
  - rollover
```
public void rollover()
```
    A column within the row batch overflowed. Prepare to absorb the rest of the in-flight row by rolling values over to a new vector, saving the complete vector for later. This column could have a value for the overflow row, or for some previous row, depending on exactly when and where the overflow occurs.
  - harvestWithLookAhead
```
public void harvestWithLookAhead()
```
    Writing of a row batch is complete. Prepare the vector for harvesting to send downstream. If this batch encountered overflow, set aside the look-ahead vector and put the full vector buffer back into the active vector.
  - isProjected
```
public boolean isProjected()
```
  - updateCardinality
```
public void updateCardinality(int cardinality)
```
  - outerCardinality
```
public int outerCardinality()
```
  - innerCardinality
```
public int innerCardinality()
```
  - buildOutput
```
public void buildOutput(TupleState tupleState)
```
  - outputSchema
```
public abstract ColumnMetadata outputSchema()
```
  - close
```
public void close()
```
  - dump
```
public void dump(HierarchicalFormatter format)
```

Class ColumnState

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

loader

addVersion

vectorState

state

writer

cardinality

outputIndex

Constructor Detail

ColumnState

Method Detail

writer

schema

vectorState

vector

allocateVectors

startBatch

rollover

harvestWithLookAhead

isProjected

updateCardinality

outerCardinality

innerCardinality

buildOutput

outputSchema

close

dump