org.apache.calcite.tools

Interface Planner

All Known Implementing Classes:

PlannerImpl

public interface Planner

A façade that covers Calcite's query planning process: parse SQL, validate the parse tree, convert the parse tree to a relational expression, and optimize the relational expression.

Planner is NOT thread safe. However, it can be reused for different queries. The consumer of this interface is responsible for calling reset() after each use of Planner that corresponds to a different query.

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Releases all internal resources utilized while this Planner exists.
RelNode	convert(SqlNode sql) Converts a SQL parse tree into a tree of relational expressions.
RelTraitSet	getEmptyTraitSet()
RelDataTypeFactory	getTypeFactory() Returns the type factory.
SqlNode	parse(String sql) Parses and validates a SQL statement.
void	reset() Resets this Planner to be used with a new query.
RelNode	transform(int ruleSetIndex, RelTraitSet requiredOutputTraits, RelNode rel) Converts one relational expression tree into another relational expression based on a particular rule set and requires set of traits.
SqlNode	validate(SqlNode sqlNode) Validates a SQL statement.

Method Detail

parse

SqlNode parse(String sql)
              throws SqlParseException

Parses and validates a SQL statement.

Parameters:

sql - The SQL statement to parse.

Returns:

The root node of the SQL parse tree.

Throws:

SqlParseException - on parse error

validate

SqlNode validate(SqlNode sqlNode)
                 throws ValidationException

Validates a SQL statement.

Parameters:

sqlNode - Root node of the SQL parse tree.

Returns:

Validated node

Throws:

ValidationException - if not valid

convert

RelNode convert(SqlNode sql)
                throws RelConversionException

Converts a SQL parse tree into a tree of relational expressions.

You must call validate(org.apache.calcite.sql.SqlNode) first.

Parameters:

sql - The root node of the SQL parse tree.

Returns:

The root node of the newly generated RelNode tree.

Throws:

RelConversionException - if the node cannot be converted or has not been validated

getTypeFactory

RelDataTypeFactory getTypeFactory()

Returns the type factory.

transform

RelNode transform(int ruleSetIndex,
                RelTraitSet requiredOutputTraits,
                RelNode rel)
                  throws RelConversionException

Converts one relational expression tree into another relational expression based on a particular rule set and requires set of traits.

Parameters:

ruleSetIndex - The RuleSet to use for conversion purposes. Note that this is zero-indexed and is based on the list and order of RuleSets provided in the construction of this Planner.

requiredOutputTraits - The set of RelTraits required of the root node at the termination of the planning cycle.

rel - The root of the RelNode tree to convert.

Returns:

The root of the new RelNode tree.

Throws:

RelConversionException - on conversion error

reset

void reset()

Resets this Planner to be used with a new query. This should be called between each new query.

close

void close()

Releases all internal resources utilized while this Planner exists. Once called, this Planner object is no longer valid.

getEmptyTraitSet

RelTraitSet getEmptyTraitSet()