Package io.trino.plugin.jdbc.aggregation

Class BaseImplementAvgBigint

java.lang.Object

io.trino.plugin.jdbc.aggregation.BaseImplementAvgBigint

All Implemented Interfaces:

AggregateFunctionRule<JdbcExpression,ParameterizedExpression>

public abstract class BaseImplementAvgBigint
extends Object
implements AggregateFunctionRule<JdbcExpression,ParameterizedExpression>

Implements avg(x) for bigint columns while preserving Trino semantics. Trino semantics say the output should be a double but pushing down the aggregation to some databases can result in rounding of the output to a bigint.

Nested Class Summary

Nested classes/interfaces inherited from interface io.trino.plugin.base.aggregation.AggregateFunctionRule

AggregateFunctionRule.RewriteContext<ExpressionResult extends Object>

Constructor Summary

Constructors

Constructor	Description
BaseImplementAvgBigint()

Method Summary

Modifier and Type	Method	Description
Pattern<AggregateFunction>	getPattern()
protected abstract String	getRewriteFormatExpression()	Implement this method for each connector supporting avg(bigint) pushdown
Optional<JdbcExpression>	rewrite(AggregateFunction aggregateFunction, Captures captures, AggregateFunctionRule.RewriteContext<ParameterizedExpression> context)

Methods inherited from class java.lang.Object

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

Constructor Details

BaseImplementAvgBigint

public BaseImplementAvgBigint()

Method Details

getPattern

public Pattern<AggregateFunction> getPattern()

Specified by:

getPattern in interface AggregateFunctionRule<JdbcExpression,ParameterizedExpression>

rewrite

public Optional<JdbcExpression> rewrite(AggregateFunction aggregateFunction,
 Captures captures,
 AggregateFunctionRule.RewriteContext<ParameterizedExpression> context)

Specified by:

rewrite in interface AggregateFunctionRule<JdbcExpression,ParameterizedExpression>

getRewriteFormatExpression

protected abstract String getRewriteFormatExpression()

Implement this method for each connector supporting avg(bigint) pushdown

Returns:

A format string expression with a single placeholder for the column name; The string expression pushes down avg to the remote database