Package org.apache.iceberg.orc
Class ORCSchemaUtil
- java.lang.Object
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- org.apache.iceberg.orc.ORCSchemaUtil
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public final class ORCSchemaUtil extends java.lang.Object
Utilities for mapping Iceberg to ORC schemas.
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
ORCSchemaUtil.BinaryType
static class
ORCSchemaUtil.LongType
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Field Summary
Fields Modifier and Type Field Description static java.lang.String
ICEBERG_BINARY_TYPE_ATTRIBUTE
The name of the ORCTypeDescription
attribute indicating the Iceberg type corresponding to an ORC binary type.static java.lang.String
ICEBERG_LONG_TYPE_ATTRIBUTE
The name of the ORCTypeDescription
attribute indicating the Iceberg type corresponding to an ORC long type.
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Method Summary
All Methods Static Methods Concrete Methods Modifier and Type Method Description static org.apache.orc.TypeDescription
buildOrcProjection(Schema schema, org.apache.orc.TypeDescription originalOrcSchema)
Converts an Iceberg schema to a corresponding ORC schema within the context of an existing ORC file schema.static org.apache.orc.TypeDescription
convert(Schema schema)
static Schema
convert(org.apache.orc.TypeDescription orcSchema)
Convert an ORC schema to an Iceberg schema.static int
fieldId(org.apache.orc.TypeDescription orcType)
static java.util.Map<java.lang.Integer,java.lang.String>
idToOrcName(Schema schema)
Generates mapping from field IDs to ORC qualified names.
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Field Detail
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ICEBERG_BINARY_TYPE_ATTRIBUTE
public static final java.lang.String ICEBERG_BINARY_TYPE_ATTRIBUTE
The name of the ORCTypeDescription
attribute indicating the Iceberg type corresponding to an ORC binary type. The values for this attribute are denoted inBinaryType
.- See Also:
- Constant Field Values
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ICEBERG_LONG_TYPE_ATTRIBUTE
public static final java.lang.String ICEBERG_LONG_TYPE_ATTRIBUTE
The name of the ORCTypeDescription
attribute indicating the Iceberg type corresponding to an ORC long type. The values for this attribute are denoted inLongType
.- See Also:
- Constant Field Values
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Method Detail
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convert
public static org.apache.orc.TypeDescription convert(Schema schema)
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convert
public static Schema convert(org.apache.orc.TypeDescription orcSchema)
Convert an ORC schema to an Iceberg schema. This method handles the convertion from the original Iceberg column mapping IDs if present in the ORC column attributes, otherwise, ORC columns with no Iceberg IDs will be ignored and skipped in the conversion.- Returns:
- the Iceberg schema
- Throws:
java.lang.IllegalArgumentException
- if ORC schema has no columns with Iceberg ID attributes
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buildOrcProjection
public static org.apache.orc.TypeDescription buildOrcProjection(Schema schema, org.apache.orc.TypeDescription originalOrcSchema)
Converts an Iceberg schema to a corresponding ORC schema within the context of an existing ORC file schema. This method also handles schema evolution from the original ORC file schema to the given Iceberg schema. It builds the desired reader schema with the schema evolution rules and pass that down to the ORC reader, which would then use its schema evolution to map that to the writer’s schema.Example:
Iceberg writer ORC writer struct<a (1): int, b (2): string> struct<a: int, b: string> struct<a (1): struct<b (2): string, c (3): date>> struct<a: struct<b:string, c:date>>
Iceberg reader ORC readerstruct<a (2): string, c (3): date> struct<b: string, c: date> struct<aa (1): struct<cc (3): date, bb (2): string>> struct<a: struct<c:date, b:string>>
- Parameters:
schema
- an Iceberg schemaoriginalOrcSchema
- an existing ORC file schema- Returns:
- the resulting ORC schema
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fieldId
public static int fieldId(org.apache.orc.TypeDescription orcType)
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idToOrcName
public static java.util.Map<java.lang.Integer,java.lang.String> idToOrcName(Schema schema)
Generates mapping from field IDs to ORC qualified names. SeeIdToOrcName
for details.
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