org.apache.druid.sql.calcite.schema

Class AbstractTableSchema

java.lang.Object

org.apache.druid.sql.calcite.schema.AbstractTableSchema

All Implemented Interfaces:

org.apache.calcite.schema.Schema

Direct Known Subclasses:

DruidSchema

public abstract class AbstractTableSchema
extends Object
implements org.apache.calcite.schema.Schema

Calcite provides two "schema" abstractions. Schema is an interface, while AbstractSchema is a base class that "locks down" the Schema.getTable(java.lang.String) method to obtain the table from a map. This forces the extensions of that class to materialize all tables in the schema, so that Calcite can pick the one it wants. This class, by contrast, provides the same defaults as AbstractSchema, but assumes its subslasses will implement getTable() to directly look up that one table, ignoring all others. Doing so lowers the cost of table resolution, especially when the system has to fetch catalog information for the table: we only fetch the information we need, not information for all tables.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.calcite.schema.Schema

org.apache.calcite.schema.Schema.TableType

Field Summary

Fields

Modifier and Type	Field and Description
protected static Set<String>	EMPTY_NAMES

Constructor Summary

Constructors

Constructor and Description
AbstractTableSchema()

Method Summary

Modifier and Type	Method and Description
org.apache.calcite.linq4j.tree.Expression	getExpression(org.apache.calcite.schema.SchemaPlus parentSchema, String name)
Set<String>	getFunctionNames()
Collection<org.apache.calcite.schema.Function>	getFunctions(String name)
org.apache.calcite.schema.Schema	getSubSchema(String name)
Set<String>	getSubSchemaNames()
org.apache.calcite.rel.type.RelProtoDataType	getType(String name)
Set<String>	getTypeNames()
boolean	isMutable()
org.apache.calcite.schema.Schema	snapshot(org.apache.calcite.schema.SchemaVersion version)

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.calcite.schema.Schema

getTable, getTableNames

Field Detail

EMPTY_NAMES

protected static final Set<String> EMPTY_NAMES

Constructor Detail

AbstractTableSchema

public AbstractTableSchema()

Method Detail

getType

public org.apache.calcite.rel.type.RelProtoDataType getType(String name)

Specified by:

getType in interface org.apache.calcite.schema.Schema

getTypeNames

public Set<String> getTypeNames()

Specified by:

getTypeNames in interface org.apache.calcite.schema.Schema

getFunctions

public Collection<org.apache.calcite.schema.Function> getFunctions(String name)

Specified by:

getFunctions in interface org.apache.calcite.schema.Schema

getFunctionNames

public Set<String> getFunctionNames()

Specified by:

getFunctionNames in interface org.apache.calcite.schema.Schema

getSubSchema

public org.apache.calcite.schema.Schema getSubSchema(String name)

Specified by:

getSubSchema in interface org.apache.calcite.schema.Schema

getSubSchemaNames

public Set<String> getSubSchemaNames()

Specified by:

getSubSchemaNames in interface org.apache.calcite.schema.Schema

getExpression

public org.apache.calcite.linq4j.tree.Expression getExpression(org.apache.calcite.schema.SchemaPlus parentSchema,
                                                               String name)

Specified by:

getExpression in interface org.apache.calcite.schema.Schema

isMutable

public boolean isMutable()

Specified by:

isMutable in interface org.apache.calcite.schema.Schema

snapshot

public org.apache.calcite.schema.Schema snapshot(org.apache.calcite.schema.SchemaVersion version)

Specified by:

snapshot in interface org.apache.calcite.schema.Schema