org.apache.arrow.adapter.jdbc

Class JdbcToArrowConfig

java.lang.Object

org.apache.arrow.adapter.jdbc.JdbcToArrowConfig

public final class JdbcToArrowConfig
extends Object

This class configures the JDBC-to-Arrow conversion process.

The allocator is used to construct the VectorSchemaRoot, and the calendar is used to define the time zone of any ArrowType.Timestamp fields that are created during the conversion. Neither field may be null.

If the includeMetadata flag is set, the Arrow field metadata will contain information from the corresponding ResultSetMetaData that was used to create the FieldType of the corresponding FieldVector.

If there are any Types.ARRAY fields in the ResultSet, the corresponding JdbcFieldInfo for the array's contents must be defined here. Unfortunately, the sub-type information cannot be retrieved from all JDBC implementations (H2 for example, returns Types.NULL for the array sub-type), so it must be configured here. The column index or name can be used to map to a JdbcFieldInfo, and that will be used for the conversion.

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_TARGET_BATCH_SIZE
static int	NO_LIMIT_BATCH_SIZE

Method Summary

Modifier and Type	Method and Description
BufferAllocator	getAllocator() The Arrow memory allocator.
JdbcFieldInfo	getArraySubTypeByColumnIndex(int index) Returns the array sub-type JdbcFieldInfo defined for the provided column index.
JdbcFieldInfo	getArraySubTypeByColumnName(String name) Returns the array sub-type JdbcFieldInfo defined for the provided column name.
RoundingMode	getBigDecimalRoundingMode()
Calendar	getCalendar() The calendar to use when defining Arrow Timestamp fields and retrieving Date, Time, or Timestamp data types from the ResultSet, or null if not converting.
Map<Integer,Map<String,String>>	getColumnMetadataByColumnIndex() Return metadata from columnIndex->meta map on per field basis or null if not provided.
JdbcFieldInfo	getExplicitTypeByColumnIndex(int index) Returns the type JdbcFieldInfo explicitly defined for the provided column index.
JdbcFieldInfo	getExplicitTypeByColumnName(String name) Returns the type JdbcFieldInfo explicitly defined for the provided column name.
Function<JdbcFieldInfo,ArrowType>	getJdbcToArrowTypeConverter() Gets the mapping between JDBC type information to Arrow type.
Map<String,String>	getSchemaMetadata() Return schema level metadata or null if not provided.
int	getTargetBatchSize() Get the target batch size for partial read.
boolean	isReuseVectorSchemaRoot() Get whether it is allowed to reuse the vector schema root.
boolean	shouldIncludeMetadata() Whether to include JDBC ResultSet field metadata in the Arrow Schema field metadata.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_TARGET_BATCH_SIZE

public static final int DEFAULT_TARGET_BATCH_SIZE

See Also:

Constant Field Values

NO_LIMIT_BATCH_SIZE

public static final int NO_LIMIT_BATCH_SIZE

See Also:

Constant Field Values

Method Detail

getCalendar

public Calendar getCalendar()

The calendar to use when defining Arrow Timestamp fields and retrieving Date, Time, or Timestamp data types from the ResultSet, or null if not converting.

Returns:

the calendar.

getAllocator

public BufferAllocator getAllocator()

The Arrow memory allocator.

Returns:

the allocator.

shouldIncludeMetadata

public boolean shouldIncludeMetadata()

Whether to include JDBC ResultSet field metadata in the Arrow Schema field metadata.

Returns:

true to include field metadata, false to exclude it.

getTargetBatchSize

public int getTargetBatchSize()

Get the target batch size for partial read.

isReuseVectorSchemaRoot

public boolean isReuseVectorSchemaRoot()

Get whether it is allowed to reuse the vector schema root.

getJdbcToArrowTypeConverter

public Function<JdbcFieldInfo,ArrowType> getJdbcToArrowTypeConverter()

Gets the mapping between JDBC type information to Arrow type.

getArraySubTypeByColumnIndex

public JdbcFieldInfo getArraySubTypeByColumnIndex(int index)

Returns the array sub-type JdbcFieldInfo defined for the provided column index.

Parameters:

index - The ResultSetMetaData column index of an Types.ARRAY type.

Returns:

The JdbcFieldInfo for that array's sub-type, or null if not defined.

getArraySubTypeByColumnName

public JdbcFieldInfo getArraySubTypeByColumnName(String name)

Returns the array sub-type JdbcFieldInfo defined for the provided column name.

Parameters:

name - The ResultSetMetaData column name of an Types.ARRAY type.

Returns:

The JdbcFieldInfo for that array's sub-type, or null if not defined.

getExplicitTypeByColumnIndex

public JdbcFieldInfo getExplicitTypeByColumnIndex(int index)

Returns the type JdbcFieldInfo explicitly defined for the provided column index.

Parameters:

index - The ResultSetMetaData column index to evaluate for explicit type mapping.

Returns:

The JdbcFieldInfo defined for the column, or null if not defined.

getExplicitTypeByColumnName

public JdbcFieldInfo getExplicitTypeByColumnName(String name)

Returns the type JdbcFieldInfo explicitly defined for the provided column name.

Parameters:

name - The ResultSetMetaData column name to evaluate for explicit type mapping.

Returns:

The JdbcFieldInfo defined for the column, or null if not defined.

getSchemaMetadata

public Map<String,String> getSchemaMetadata()

Return schema level metadata or null if not provided.

getColumnMetadataByColumnIndex

public Map<Integer,Map<String,String>> getColumnMetadataByColumnIndex()

Return metadata from columnIndex->meta map on per field basis or null if not provided.

getBigDecimalRoundingMode

public RoundingMode getBigDecimalRoundingMode()