com.bigdata.relation.accesspath

Interface IAbstractAccessPath<R>

Type Parameters:

R - The generic type of the [R]elation elements of the IRelation.

All Known Subinterfaces:

IAccessPath<R>, IBindingSetAccessPath<R>

All Known Implementing Classes:

AccessPath, AccessPathFusedView, ArrayAccessPath, BackchainAccessPath, EmptyAccessPath, SPOAccessPath

public interface IAbstractAccessPath<R>

A common interface for all access paths.

Version:

$Id$

Author:

Bryan Thompson

Method Summary

Methods

Modifier and Type	Method and Description
IPredicate<R>	getPredicate() The constraints on the IAccessPath.
boolean	isEmpty() True iff the access path is empty (there are no matches for the IPredicate) This is more conclusive than #rangeCount() since you MAY have a non-zero range count when the key range is in fact empty (there may be "deleted" index entries within the key range).
long	rangeCount(boolean exact) Return the maximum #of elements spanned by the IPredicate.
long	removeAll() Remove all elements selected by the IPredicate (optional operation).

Method Detail

getPredicate

IPredicate<R> getPredicate()

The constraints on the IAccessPath.

isEmpty

boolean isEmpty()

True iff the access path is empty (there are no matches for the IPredicate) This is more conclusive than #rangeCount() since you MAY have a non-zero range count when the key range is in fact empty (there may be "deleted" index entries within the key range).

rangeCount

long rangeCount(boolean exact)

Return the maximum #of elements spanned by the IPredicate.

Note: When there is an IFilter on the IPredicate the exact range count MUST apply that IFilter, which means that it will be required to traverse the index counting tuples which pass the IFilter. However, IFilters are ignored for the fast range count.

Parameters:

exact - When true, the result will be an exact count and may require a key-range scan. When false, the result will be an upper bound IFF delete markers are provisioned for the backing index (delete markers are required for transactions and for scale-out indices).

See Also:

IRangeQuery

removeAll

long removeAll()

Remove all elements selected by the IPredicate (optional operation).

Returns:

The #of elements that were removed.