Hello. Let me share what I know. Indexing is always done and read in units called segments. When the IndexWriter writes new indexes, it is creating new segments. The important point here is that it does not touch the existing segments. This ensures that the consistency for searchers using the existing segments can be maintained. For reference, even when merging, it is done by combining the segments in a separate segment file and then removing the old segments. This is what I know. If there are any mistakes, I would appreciate it if someone could correct me.
Thank you. 2024년 5월 17일 (금) 오후 11:30, Alexander Panchenko <ird...@gmail.com>님이 작성: > Hello! > > I was examining the Lucene source code with the desire to figure out how > an IndexSearcher could be safely used while IndexWriter is open on the same > directory. My concern is that when an IndexWriter is open, it could remove > existing files in the directory (for example: during the merge procedure), > meanwhile these files are being used by IndexSearcher. I'm asking because I > want to implement my own directory and I'm not sure if it's safe to keep an > IndexWriter open while I'm using IndexSearch to execute search queries. I > see that once an IndexSearcher is open, it opens several segments files and > keeps them open. > > Is it safe to use IndexWriter and IdnexSearcher at the same time? And if > so, how does IndexWriter not break the active IndexSearcher? > > Thank you. >
