org.apache.drill.metastore.metadata

Interface Metadata

All Known Subinterfaces:

TableMetadata

All Known Implementing Classes:

BaseMetadata, BaseTableMetadata, FileMetadata, NonInterestingColumnsMetadata, PartitionMetadata, RowGroupMetadata, SegmentMetadata

public interface Metadata

Provider of tuple schema, column metadata, and statistics for table, partition, file or row group.

Method Summary

Modifier and Type	Method and Description
boolean	containsExactStatistics(StatisticsKind<?> statisticsKind) Checks whether specified statistics kind is set in this non-column statistics and it corresponds to the exact statistics value.
ColumnMetadata	getColumn(SchemaPath name) Returns metadata description for the specified column
Map<SchemaPath,ColumnStatistics<?>>	getColumnsStatistics() Returns statistics stored in current metadata represented as Map of column SchemaPaths and corresponding ColumnStatistics.
ColumnStatistics<?>	getColumnStatistics(SchemaPath columnName) Returns statistics for specified column stored in current metadata.
MetadataInfo	getMetadataInfo()
TupleMetadata	getSchema() Returns schema stored in current metadata represented as TupleMetadata.
<V> V	getStatistic(StatisticsKind<V> statisticsKind) Returns value of non-column statistics which corresponds to specified StatisticsKind.
<V> V	getStatisticsForColumn(SchemaPath columnName, StatisticsKind<V> statisticsKind) Returns value of column statistics which corresponds to specified StatisticsKind for column with specified columnName.
TableInfo	getTableInfo()
TableMetadataUnit	toMetadataUnit() Converts Metadata implementation into TableMetadataUnit instance which will be used to write data into Drill Metastore Tables.

Method Detail

getColumnsStatistics

Map<SchemaPath,ColumnStatistics<?>> getColumnsStatistics()

Returns statistics stored in current metadata represented as Map of column SchemaPaths and corresponding ColumnStatistics.

Returns:

statistics stored in current metadata

getColumnStatistics

ColumnStatistics<?> getColumnStatistics(SchemaPath columnName)

Returns statistics for specified column stored in current metadata.

Parameters:

columnName - column whose statistics should be returned

Returns:

statistics for specified column

getSchema

TupleMetadata getSchema()

Returns schema stored in current metadata represented as TupleMetadata.

Returns:

schema stored in current metadata

getStatistic

<V> V getStatistic(StatisticsKind<V> statisticsKind)

Returns value of non-column statistics which corresponds to specified StatisticsKind.

Parameters:

statisticsKind - statistics kind whose value should be returned

Returns:

value of non-column statistics

containsExactStatistics

boolean containsExactStatistics(StatisticsKind<?> statisticsKind)

Checks whether specified statistics kind is set in this non-column statistics and it corresponds to the exact statistics value.

Parameters:

statisticsKind - statistics kind to check

Returns:

true if value which corresponds to the specified statistics kind is exact

getStatisticsForColumn

<V> V getStatisticsForColumn(SchemaPath columnName,
                             StatisticsKind<V> statisticsKind)

Returns value of column statistics which corresponds to specified StatisticsKind for column with specified columnName.

Parameters:

columnName - name of the column

statisticsKind - statistics kind whose value should be returned

Returns:

value of column statistics

getColumn

ColumnMetadata getColumn(SchemaPath name)

Returns metadata description for the specified column

Parameters:

name - column name, whose metadata type info should be returned

Returns:

ColumnMetadata schema description of the column

getTableInfo

TableInfo getTableInfo()

getMetadataInfo

MetadataInfo getMetadataInfo()

toMetadataUnit

TableMetadataUnit toMetadataUnit()

Converts Metadata implementation into TableMetadataUnit instance which will be used to write data into Drill Metastore Tables.

Returns:

metadata unit instance