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This article mainly explains "Lucene's file structure is what", interested friends may wish to take a look. The method introduced in this paper is simple, fast and practical. Let's let Xiaobian take you to learn "what is the file structure of Lucene"!

Lucene's file structure is a hierarchy.

Lucene file hierarchy contains:

If I had to make an analogy:

The index here is equivalent to the table in the database. When the number of records in the table reaches a certain amount, we have to partition the table.

The table is divided into two parts.

That is, an index can be broken down into multiple segments.

The records in the database table are stored in different partitions, where the documents are equivalent to the records in the database table. Different documents are stored in different segments.

A slight difference from table partitioning is that the segments here can be merged into a new segment.

An index contains multiple segments, each segment contains one or more documents, and documents contain multiple domains, which can be segmented into one or more terms.

Lucene index holds forward and backward information.

Forward information: holds the index-to-word inclusion relationships hierarchically.

index-segment-document-domain-word

An index contains which segments, which documents each segment contains, which domains are contained in documents, and which terms the domains are divided into.

Reverse information: word-to-document mapping.

In the previous article (1) in this series, we defined this mapping from words to documents as an inverted list. Through the inverted list, we can see in which documents each word appears.

At this point, I believe that everyone has a deeper understanding of "Lucene's file structure is what", may wish to actually operate it! Here is the website, more related content can enter the relevant channels for inquiry, pay attention to us, continue to learn!

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