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2021SC@SDUSC catalogue Hash index In addition to using B-Tree index, postgreSQL can also use hash index. Hash index has faster query speed. This article mainly explains the principle of hash index, compares it with B-Tree, and analyzes the relevant data structure of hash index in the source code. Hash indexing principle Hash table The ...

Reference: https://eco.dameng.com Guidelines for managing indexes Index: provides a faster path to access table data DM8 common types typedescribeClustered indexEach ordinary table has and has only one clustered indexunique indexThe index data is unique according to the index keyFunctional indexContains the precomputed value of the ...

1. General I talked about the installation of Elasticsearch before. Today, let's talk about the basic use of Elasticsearch. two   Use of Elasticsearch index The index is equivalent to a table in mysql. 2.1 index creation 1) Head plug-in mode Select the index tab, click [new index], enter the index name, number of slices and num ...