Package org.apache.lucene.index

Class MultiPassIndexSplitter

java.lang.Object

org.apache.lucene.index.MultiPassIndexSplitter

public class MultiPassIndexSplitter
extends java.lang.Object

This tool splits input index into multiple equal parts. The method employed here uses IndexWriter.addIndexes(IndexReader[]) where the input data comes from the input index with artificially applied deletes to the document id-s that fall outside the selected partition.

Note 1: Deletes are only applied to a buffered list of deleted docs and don't affect the source index - this tool works also with read-only indexes.

Note 2: the disadvantage of this tool is that source index needs to be read as many times as there are parts to be created, hence the name of this tool.

NOTE: this tool is unaware of documents added atomically via IndexWriter.addDocuments(java.lang.Iterable<? extends java.lang.Iterable<? extends org.apache.lucene.index.IndexableField>>) or IndexWriter.updateDocuments(org.apache.lucene.index.Term, java.lang.Iterable<? extends java.lang.Iterable<? extends org.apache.lucene.index.IndexableField>>), which means it can easily break up such document groups.

Constructor Summary

Constructors

Constructor	Description
MultiPassIndexSplitter()

Method Summary

Modifier and Type	Method	Description
static void	main(java.lang.String[] args)
void	split(Version version, IndexReader in, Directory[] outputs, boolean seq)	Split source index into multiple parts.

Methods inherited from class java.lang.Object

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

Constructor Detail

MultiPassIndexSplitter

public MultiPassIndexSplitter()

Method Detail

split

public void split(Version version,
                  IndexReader in,
                  Directory[] outputs,
                  boolean seq)
           throws java.io.IOException

Split source index into multiple parts.

Parameters:

in - source index, can have deletions, can have multiple segments (or multiple readers).

outputs - list of directories where the output parts will be stored.

seq - if true, then the source index will be split into equal increasing ranges of document id-s. If false, source document id-s will be assigned in a deterministic round-robin fashion to one of the output splits.

Throws:

java.io.IOException - If there is a low-level I/O error

main

public static void main(java.lang.String[] args)
                 throws java.lang.Exception

Throws:

java.lang.Exception