Searching method for relational data base and full text searching combination

Abstract

This invention discloses an index method with the combination of the relation data base and whole paper index, and it overcomes the disadvantage of the combination of SQL search in the relation data base and the whole paper search and the efficient is low. It includes the above data base, founds the index base of the data base to the needed property field in every data base, and founds the whole paper search base by the whole paper searching engine. It can divide the searching requirement into data base search and whole paper search on need during search, and it can separately form the corresponding inquire word. The index search condition is accord with the SQL criterion, the whole paper search condition is accord with the whole paper expression criterion. Then the first submits to the relation data base to do data base search, the latter submits to the whole paper searching engine to search. This can realize the parallel execution of two searches, improves the ability of the search greatly, and can provide the special whole paper search scheme.

Description

technical field [0001] The invention relates to a retrieval method, in particular to a method for improving retrieval efficiency based on the combination of a full-text retrieval mechanism and a relational data field retrieval. Background technique [0002] Relational databases and full-text search engines are two technologies that have been around for a long time and have developed quite maturely. Both of them can provide data storage and retrieval. [0003] Relational database has a longer history and more mature technology than full-text retrieval technology. It originated from the relational database theory created by Edgar Codd from the 1960s to the early 1970s. Later generations developed on the basis of his theory A series of RDBMS. The advantage of relational data lies in its support for SQL standards, standardized, flexible and powerful retrieval syntax, and its support for complex data models based on two-dimensional table-based relational theory. Through long-ter...

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Problems solved by technology

[0014] (1) When performing fuzzy matching retrieval on string-type fields, pre-containment (that is, fuzzy retrieval that starts with the search term) can use the index to achieve efficient retrieval, but for post-containment (that is, fuzzy retrieval that ends with the search term) ) and inclusion (that is, the fuzzy search in the middle of the search term) cannot make use of the index so that this type of search is usually inefficient, and the efficiency problem is particularly prominent in the case of long string fields

[0015] (2) For text fields, including: CLOB (Oracle, DB2), Text (SQL Server, Sybase), etc., because indexes cannot be created, indexes cannot be used for efficient retrieval of such fields

The third case is related to the specific application. In the database application system, the text (text files, such as: TXT, Doc, PDF, HTML, etc.) is usually placed in the file system, and only a path (or URI) is recorded in the database. , in this case, the database index mechanism is powerless

[0016] (3) The final problem comes from the flexibility of retrieval conditions. The retrieval syntax of database retrieval comes from the SQL standard, which can carry out logical conditions (=, , >, =, <=, like, between and) , Boolean search (And, Or, Not) and grouping search conditions to meet most of the search requirements, but for dictionary-based searches such as word search, phrase search, sentence search, paragraph search, synonyms, etc., it cannot be satisfied. And this is the advantage of full-text search

[0017] 2. As far as full-text retrieval is concerned, there is no international standard for retrieval syntax similar to SQL, and more retrieval services are provided through function calls from the interface level. This is its shortcoming

[0022] (3) Insufficient support for Chinese

[0023] (4) The query statement is not uniform and does not form a standard

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