Package org.apache.drill.exec.record.metadata
package org.apache.drill.exec.record.metadata
Provides a fluent schema builder. Handles all
forms of Drill schemas, with emphasis on ease of use for the typical
cases (flat schema or nested maps.) Enables construction of unions,
union lists (AKA "list vector") repeated lists and combinations of
the above structures.
SchemaBuilder
Drill normally writes data to vectors, then "discovers" the row set schema based on the
data written. It is usually far easier to simply declare a schema, then
read and write data according to that schema. The schema builder provides a simple,
fluent tool to create a row set schema. That schema then drives the row set readers
and writers, the row set printer and the row set comparison.
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ClassDescriptionAbstract definition of column metadata.Describes a base column type for map, dict, repeated map and repeated dict.Base class for an object with properties.Build a column schema (AKA "materialized field") based on name and a variety of schema options.Metadata description of a column including names, types and structure information.Rough characterization of Drill types into metadata categories.Internal structure for building a dict.A dynamic column has a name but not a type.Internal structure for building a map.Describes a map and repeated map.A collection of utility methods for working with column and tuple metadata.Primitive (non-map) column.Interface for an object that defines properties.Utilities to get/set typed values within a propertied objectBuilder for a repeated list.Builder of a row set schema expressed as a list of materialized fields.Internal tuple builder shared by the schema and map builders.Metadata description of the schema of a row or a map.Implementation of a tuple name space.Defines the schema of a tuple: either the top-level row or a nested "map" (really structure).Builds unions or (non-repeated) lists (which implicitly contain unions.)Describes the contents of a list or union field.