com.orientechnologies.orient.core.sql.functions

Interface OIndexableSQLFunction

All Superinterfaces:

OSQLFunction

All Known Implementing Classes:

OLuceneSearchFunctionTemplate, OLuceneSearchMoreLikeThisFunction, OLuceneSearchOnClassFunction, OLuceneSearchOnFieldsFunction, OLuceneSearchOnIndexFunction, OSpatialFunctionAbstractIndexable, OSTContainsFunction, OSTDistanceSphereFunction, OSTDWithinFunction, OSTIntersectsFunction, OSTWithinFunction

public interface OIndexableSQLFunction
extends OSQLFunction

This interface represents SQL functions whose implementation can rely on an index. If used in a WHERE condition, this kind of function can be invoked to retrieve target records from an underlying structure, like an index

Author:

Luigi Dell'Aquila (l.dellaquila-(at)-orientdb.com)

Method Summary

Modifier and Type	Method and Description
boolean	allowsIndexedExecution(OFromClause target, OBinaryCompareOperator operator, Object rightValue, OCommandContext ctx, OExpression... args) Checks if this function can be used to fetch data from this target and with these arguments (eg.
boolean	canExecuteInline(OFromClause target, OBinaryCompareOperator operator, Object rightValue, OCommandContext ctx, OExpression... args) checks if the function can be used even on single records, not as an indexed function (even if the index does not exist at all)
long	estimate(OFromClause target, OBinaryCompareOperator operator, Object rightValue, OCommandContext ctx, OExpression... args) estimates the number of entries returned by searchFromTarget() with these parameters
Iterable<OIdentifiable>	searchFromTarget(OFromClause target, OBinaryCompareOperator operator, Object rightValue, OCommandContext ctx, OExpression... args) returns all the entries belonging to the target that match the binary condition where this function appears
boolean	shouldExecuteAfterSearch(OFromClause target, OBinaryCompareOperator operator, Object rightValue, OCommandContext ctx, OExpression... args) Checks if this function should be called even if the method searchFromTarget(com.orientechnologies.orient.core.sql.parser.OFromClause, com.orientechnologies.orient.core.sql.parser.OBinaryCompareOperator, java.lang.Object, com.orientechnologies.orient.core.command.OCommandContext, com.orientechnologies.orient.core.sql.parser.OExpression...) is executed.

Methods inherited from interface com.orientechnologies.orient.core.sql.functions.OSQLFunction

aggregateResults, config, execute, filterResult, getMaxParams, getMinParams, getName, getResult, getSyntax, mergeDistributedResult, setResult, shouldMergeDistributedResult

Method Detail

searchFromTarget

Iterable<OIdentifiable> searchFromTarget(OFromClause target,
                                         OBinaryCompareOperator operator,
                                         Object rightValue,
                                         OCommandContext ctx,
                                         OExpression... args)

returns all the entries belonging to the target that match the binary condition where this function appears

Parameters:

target - the query target

operator - the operator after the function, eg. in select from Foo where myFunction(name) > 4 the operator is >

rightValue - the value that has to be compared to the function result, eg. in select from Foo where myFunction(name) > 4 the right value is 4

ctx - the command context for this query

args - the function arguments, eg. in select from Foo where myFunction(name) > 4 the arguments are [name]

Returns:

an iterable of records that match the condition; null means that the execution could not be performed for some reason.

estimate

long estimate(OFromClause target,
              OBinaryCompareOperator operator,
              Object rightValue,
              OCommandContext ctx,
              OExpression... args)

estimates the number of entries returned by searchFromTarget() with these parameters

Parameters:

target - the query target

operator - the operator after the function, eg. in select from Foo where myFunction(name) > 4 the operator is >

rightValue - the value that has to be compared to the function result, eg. in select from Foo where myFunction(name) > 4 the right value is 4

ctx - the command context for this query

args - the function arguments, eg. in select from Foo where myFunction(name) > 4 the arguments are [name]

Returns:

an estimantion of how many entries will be returned by searchFromTarget() with these parameters, -1 if the estimation cannot be done

canExecuteInline

boolean canExecuteInline(OFromClause target,
                         OBinaryCompareOperator operator,
                         Object rightValue,
                         OCommandContext ctx,
                         OExpression... args)

checks if the function can be used even on single records, not as an indexed function (even if the index does not exist at all)

Parameters:

target - the query target

operator - the operator after the function, eg. in select from Foo where myFunction(name) > 4 the operator is >

rightValue - the value that has to be compared to the function result, eg. in select from Foo where myFunction(name) > 4 the right value is 4

ctx - the command context for this query

args - the function arguments, eg. in select from Foo where myFunction(name) > 4 the arguments are [name]

Returns:

true if the funciton can be calculated without the index. False otherwise

allowsIndexedExecution

boolean allowsIndexedExecution(OFromClause target,
                               OBinaryCompareOperator operator,
                               Object rightValue,
                               OCommandContext ctx,
                               OExpression... args)

Checks if this function can be used to fetch data from this target and with these arguments (eg. if the index exists on this target and it's defined on these fields)

Parameters:

target - the query target

operator - the operator after the function, eg. in select from Foo where myFunction(name) > 4 the operator is >

rightValue - the value that has to be compared to the function result, eg. in select from Foo where myFunction(name) > 4 the right value is 4

ctx - the command context for this query

args - the function arguments, eg. in select from Foo where myFunction(name) > 4 the arguments are [name]

Returns:

True if the funciton can be used to fetch from an index. False otherwise

shouldExecuteAfterSearch

boolean shouldExecuteAfterSearch(OFromClause target,
                                 OBinaryCompareOperator operator,
                                 Object rightValue,
                                 OCommandContext ctx,
                                 OExpression... args)

Checks if this function should be called even if the method searchFromTarget(com.orientechnologies.orient.core.sql.parser.OFromClause, com.orientechnologies.orient.core.sql.parser.OBinaryCompareOperator, java.lang.Object, com.orientechnologies.orient.core.command.OCommandContext, com.orientechnologies.orient.core.sql.parser.OExpression...) is executed.

Parameters:

target - the query target

operator - the operator after the function, eg. in select from Foo where myFunction(name) > 4 the operator is >

rightValue - the value that has to be compared to the function result, eg. in select from Foo where myFunction(name) > 4 the right value is 4

ctx - the command context for this query

args - the function arguments, eg. in select from Foo where myFunction(name) > 4 the arguments are [name]

Returns:

True if this function should be called even if the method searchFromTarget(com.orientechnologies.orient.core.sql.parser.OFromClause, com.orientechnologies.orient.core.sql.parser.OBinaryCompareOperator, java.lang.Object, com.orientechnologies.orient.core.command.OCommandContext, com.orientechnologies.orient.core.sql.parser.OExpression...) is executed. False otherwise