Package org.apache.iotdb.db.mpp.plan.analyze

Class ExpressionAnalyzer

java.lang.Object

org.apache.iotdb.db.mpp.plan.analyze.ExpressionAnalyzer

public class ExpressionAnalyzer
extends java.lang.Object

Constructor Summary

Constructors

Constructor	Description
ExpressionAnalyzer()

Method Summary

Modifier and Type	Method	Description
static void	checkIsAllMeasurement(Expression expression)	Check if all suffix paths in expression are measurements or one-level wildcards, used in ALIGN BY DEVICE query or GroupByLevel query.
static boolean	checkIsNeedTransform(Expression expression)	Check for arithmetic expression, logical expression, UDF.
static java.util.List<Expression>	concatDeviceAndRemoveWildcard(Expression expression, org.apache.iotdb.commons.path.PartialPath devicePath, ISchemaTree schemaTree, TypeProvider typeProvider)	Concat expression with the device path in the FROM clause.And then, bind schema (PartialPath -> MeasurementPath) and removes wildcards in Expression.
static java.util.List<org.apache.iotdb.commons.path.PartialPath>	concatExpressionWithSuffixPaths(Expression expression, java.util.List<org.apache.iotdb.commons.path.PartialPath> prefixPaths)	Concat suffix path in SELECT or WITHOUT NULL clause with the prefix path in the FROM clause.
static java.util.List<Expression>	concatExpressionWithSuffixPaths(Expression expression, java.util.List<org.apache.iotdb.commons.path.PartialPath> prefixPaths, PathPatternTree patternTree)	Concat suffix path in SELECT or WITHOUT NULL clause with the prefix path in the FROM clause.
static void	constructPatternTreeFromExpression(Expression predicate, java.util.List<org.apache.iotdb.commons.path.PartialPath> prefixPaths, PathPatternTree patternTree)	Concat suffix path in WHERE clause with the prefix path in the FROM clause and Construct a PathPatternTree.
static Expression	evaluatePredicate(Expression predicate)
static java.lang.String	getDeviceNameInSourceExpression(Expression expression)
static Expression	getMeasurementExpression(Expression expression)
static ResultColumn.ColumnType	identifyOutputColumnType(Expression expression, boolean isRoot)	Identify the expression is a valid built-in aggregation function.
static Expression	removeAliasFromExpression(Expression expression)	Remove alias from expression.
static java.util.List<Expression>	removeWildcardInExpression(Expression expression, ISchemaTree schemaTree)	Bind schema (PartialPath -> MeasurementPath) and removes wildcards in Expression.
static java.util.List<Expression>	removeWildcardInFilter(Expression predicate, java.util.List<org.apache.iotdb.commons.path.PartialPath> prefixPaths, ISchemaTree schemaTree, TypeProvider typeProvider, boolean isWhere)	Concat suffix path in WHERE and HAVING clause with the prefix path in the FROM clause.
static java.util.List<Expression>	removeWildcardInFilterByDevice(Expression predicate, org.apache.iotdb.commons.path.PartialPath devicePath, ISchemaTree schemaTree, TypeProvider typeProvider, boolean isWhere)	Concat measurement in WHERE and HAVING clause with device path.
static Expression	replaceRawPathWithGroupedPath(Expression predicate, java.util.Map<Expression,Expression> rawPathToGroupedPathMapInHaving)
static java.util.List<Expression>	searchAggregationExpressions(Expression expression)	Search for built-in aggregate functions subexpressions.
static java.util.List<Expression>	searchSourceExpressions(Expression expression, boolean isRawDataSource)	Search for subexpressions that can be queried natively, including time series raw data and built-in aggregate functions.
static org.apache.iotdb.tsfile.utils.Pair<org.apache.iotdb.tsfile.read.filter.basic.Filter,java.lang.Boolean>	transformToGlobalTimeFilter(Expression predicate, boolean canRewrite, boolean isFirstOr)	Extract global time filter from query filter.
static void	updateTypeProvider(Expression expression, TypeProvider typeProvider)	Update typeProvider by expression.

Methods inherited from class java.lang.Object

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

Constructor Detail

ExpressionAnalyzer

public ExpressionAnalyzer()

Method Detail

checkIsAllMeasurement

public static void checkIsAllMeasurement(Expression expression)

Check if all suffix paths in expression are measurements or one-level wildcards, used in ALIGN BY DEVICE query or GroupByLevel query. If not, throw a SemanticException.

Parameters:

expression - expression to be checked

identifyOutputColumnType

public static ResultColumn.ColumnType identifyOutputColumnType(Expression expression,
                                                               boolean isRoot)

Identify the expression is a valid built-in aggregation function.

Parameters:

expression - expression to be checked

Returns:

true if this expression is valid

concatExpressionWithSuffixPaths

public static java.util.List<Expression> concatExpressionWithSuffixPaths(Expression expression,
                                                                         java.util.List<org.apache.iotdb.commons.path.PartialPath> prefixPaths,
                                                                         PathPatternTree patternTree)

Concat suffix path in SELECT or WITHOUT NULL clause with the prefix path in the FROM clause. and Construct a PathPatternTree.

Parameters:

expression - expression in SELECT or WITHOUT NULL clause which may include suffix paths

prefixPaths - prefix paths in the FROM clause

patternTree - a PathPatternTree contains all paths to query

Returns:

the concatenated expression list

concatExpressionWithSuffixPaths

public static java.util.List<org.apache.iotdb.commons.path.PartialPath> concatExpressionWithSuffixPaths(Expression expression,
                                                                                                        java.util.List<org.apache.iotdb.commons.path.PartialPath> prefixPaths)

Concat suffix path in SELECT or WITHOUT NULL clause with the prefix path in the FROM clause.

Parameters:

expression - expression in SELECT or WITHOUT NULL clause which may include suffix paths

prefixPaths - prefix paths in the FROM clause

Returns:

the concatenated partialPath list

constructPatternTreeFromExpression

public static void constructPatternTreeFromExpression(Expression predicate,
                                                      java.util.List<org.apache.iotdb.commons.path.PartialPath> prefixPaths,
                                                      PathPatternTree patternTree)

Concat suffix path in WHERE clause with the prefix path in the FROM clause and Construct a PathPatternTree. This method return void, i.e. will not rewrite the statement.

Parameters:

predicate - expression in WHERE clause

prefixPaths - prefix paths in the FROM clause

patternTree - a PathPatternTree contains all paths to query

removeWildcardInExpression

public static java.util.List<Expression> removeWildcardInExpression(Expression expression,
                                                                    ISchemaTree schemaTree)

Bind schema (PartialPath -> MeasurementPath) and removes wildcards in Expression.

Parameters:

schemaTree - interface for querying schema information

Returns:

the expression list after binding schema

removeWildcardInFilter

public static java.util.List<Expression> removeWildcardInFilter(Expression predicate,
                                                                java.util.List<org.apache.iotdb.commons.path.PartialPath> prefixPaths,
                                                                ISchemaTree schemaTree,
                                                                TypeProvider typeProvider,
                                                                boolean isWhere)

Concat suffix path in WHERE and HAVING clause with the prefix path in the FROM clause. And then, bind schema (PartialPath -> MeasurementPath) and removes wildcards in Expression.

Parameters:

prefixPaths - prefix paths in the FROM clause

schemaTree - interface for querying schema information

typeProvider - a map to record output symbols and their data types

Returns:

the expression list with full path and after binding schema

replaceRawPathWithGroupedPath

public static Expression replaceRawPathWithGroupedPath(Expression predicate,
                                                       java.util.Map<Expression,Expression> rawPathToGroupedPathMapInHaving)

concatDeviceAndRemoveWildcard

public static java.util.List<Expression> concatDeviceAndRemoveWildcard(Expression expression,
                                                                       org.apache.iotdb.commons.path.PartialPath devicePath,
                                                                       ISchemaTree schemaTree,
                                                                       TypeProvider typeProvider)

Concat expression with the device path in the FROM clause.And then, bind schema (PartialPath -> MeasurementPath) and removes wildcards in Expression. This method used in ALIGN BY DEVICE query.

Parameters:

devicePath - device path in the FROM clause

Returns:

expression list with full path and after binding schema

removeWildcardInFilterByDevice

public static java.util.List<Expression> removeWildcardInFilterByDevice(Expression predicate,
                                                                        org.apache.iotdb.commons.path.PartialPath devicePath,
                                                                        ISchemaTree schemaTree,
                                                                        TypeProvider typeProvider,
                                                                        boolean isWhere)

Concat measurement in WHERE and HAVING clause with device path. And then, bind schema (PartialPath -> MeasurementPath) and removes wildcards.

Returns:

the expression list with full path and after binding schema

transformToGlobalTimeFilter

public static org.apache.iotdb.tsfile.utils.Pair<org.apache.iotdb.tsfile.read.filter.basic.Filter,java.lang.Boolean> transformToGlobalTimeFilter(Expression predicate,
                                                                                                                                                       boolean canRewrite,
                                                                                                                                                       boolean isFirstOr)

Extract global time filter from query filter.

Parameters:

predicate - raw query filter

canRewrite - determined by the father of current expression

isFirstOr - whether it is the first LogicOrExpression encountered

Returns:

global time filter

searchSourceExpressions

public static java.util.List<Expression> searchSourceExpressions(Expression expression,
                                                                 boolean isRawDataSource)

Search for subexpressions that can be queried natively, including time series raw data and built-in aggregate functions.

Parameters:

expression - expression to be searched

isRawDataSource - if true, built-in aggregate functions are not be returned

Returns:

searched subexpression list

searchAggregationExpressions

public static java.util.List<Expression> searchAggregationExpressions(Expression expression)

Search for built-in aggregate functions subexpressions.

Parameters:

expression - expression to be searched

Returns:

searched aggregate functions list

updateTypeProvider

public static void updateTypeProvider(Expression expression,
                                      TypeProvider typeProvider)

Update typeProvider by expression.

removeAliasFromExpression

public static Expression removeAliasFromExpression(Expression expression)

Remove alias from expression. eg: root.sg.d1.status + 1 -> root.sg.d1.s2 + 1

Returns:

expression after removing alias

checkIsNeedTransform

public static boolean checkIsNeedTransform(Expression expression)

Check for arithmetic expression, logical expression, UDF. Returns true if it exists.

getDeviceNameInSourceExpression

public static java.lang.String getDeviceNameInSourceExpression(Expression expression)

getMeasurementExpression

public static Expression getMeasurementExpression(Expression expression)

evaluatePredicate

public static Expression evaluatePredicate(Expression predicate)