Package org.apache.calcite.adapter.elasticsearch

Class PredicateAnalyzer

java.lang.Object

org.apache.calcite.adapter.elasticsearch.PredicateAnalyzer

class PredicateAnalyzer
extends java.lang.Object

Query predicate analyzer. Uses visitor pattern to traverse existing expression and convert it to QueryBuilders.QueryBuilder.

Major part of this class have been copied from dremio ES adapter (thanks to their team for improving calcite-ES integration).

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static class	PredicateAnalyzer.CastExpression	SQL cast: cast(col as INTEGER)
(package private) static class	PredicateAnalyzer.CompoundQueryExpression	Builds conjunctions / disjunctions based on existing expressions
(package private) static interface	PredicateAnalyzer.Expression	Empty interface; exists only to define type hierarchy
(package private) static class	PredicateAnalyzer.ExpressionNotAnalyzableException	Thrown when RelNode expression can't be processed (or converted into ES query)
(package private) static class	PredicateAnalyzer.LiteralExpression	Literal like 'foo' or 42 or true etc.
(package private) static class	PredicateAnalyzer.NamedFieldExpression	Used for bind variables
private static class	PredicateAnalyzer.NotLikeConverter	Converts expressions of the form NOT(LIKE(...)) into NOT_LIKE(...)
private static class	PredicateAnalyzer.PredicateAnalyzerException	Internal exception
(package private) static class	PredicateAnalyzer.QueryExpression	Main expression operators (like equals, gt, exists etc.)
(package private) static class	PredicateAnalyzer.SimpleQueryExpression	Usually basic expression of type a = 'val' or b > 42.
(package private) static interface	PredicateAnalyzer.TerminalExpression	Empty interface; exists only to define type hierarchy
private static class	PredicateAnalyzer.Visitor	Traverses RexNode tree and builds ES query.

Constructor Summary

Constructors

Modifier	Constructor	Description
private	PredicateAnalyzer()

Method Summary

Modifier and Type	Method	Description
private static QueryBuilders.RangeQueryBuilder	addFormatIfNecessary(PredicateAnalyzer.LiteralExpression literal, QueryBuilders.RangeQueryBuilder rangeQueryBuilder)	By default, range queries on date/time need use the format of the source to parse the literal.
(package private) static QueryBuilders.QueryBuilder	analyze(RexNode expression)	Walks the expression tree, attempting to convert the entire tree into an equivalent Elasticsearch query filter.
private static void	checkForIncompatibleDateTimeOperands(RexCall call)	If one operand in a binary operator is a DateTime type, but the other isn't, we should not push down the predicate

Methods inherited from class java.lang.Object

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

Constructor Detail

PredicateAnalyzer

private PredicateAnalyzer()

Method Detail

analyze

static QueryBuilders.QueryBuilder analyze(RexNode expression)
                                   throws PredicateAnalyzer.ExpressionNotAnalyzableException

Walks the expression tree, attempting to convert the entire tree into an equivalent Elasticsearch query filter. If an error occurs, or if it is determined that the expression cannot be converted, an exception is thrown and an error message logged.

Callers should catch ExpressionNotAnalyzableException and fall back to not using push-down filters.

Parameters:

expression - expression to analyze

Returns:

search query which can be used to query ES cluster

Throws:

PredicateAnalyzer.ExpressionNotAnalyzableException - when expression can't processed by this analyzer

addFormatIfNecessary

private static QueryBuilders.RangeQueryBuilder addFormatIfNecessary(PredicateAnalyzer.LiteralExpression literal,
                                                                    QueryBuilders.RangeQueryBuilder rangeQueryBuilder)

By default, range queries on date/time need use the format of the source to parse the literal. So we need to specify that the literal has "date_time" format

Parameters:

literal - literal value

rangeQueryBuilder - query builder to optionally add format expression

Returns:

existing builder with possible format attribute

checkForIncompatibleDateTimeOperands

private static void checkForIncompatibleDateTimeOperands(RexCall call)

If one operand in a binary operator is a DateTime type, but the other isn't, we should not push down the predicate

Parameters:

call - current node being evaluated