Postgresql ILIKE与TSEARCH [英] Postgresql ILIKE versus TSEARCH

问题描述

  SELECT * FROM some-table 
 WHERE field1 ILIKE％thing％
 OR field2 ILIKE％thing
 OR field3 ILIKE％thing; 
  

列几乎都是varchar（50）或其附近。现在我明白为了提高性能，我应该为搜索所在的领域编制索引。我应该考虑用TSEARCH完全取代ILIKE吗？

解决方案全文搜索设置与包含 。它阻止了单词等，所以你可以匹配汽车与汽车。

如果你真的想要一个快速ILIKE，那么没有标准数据库索引或FTS会有帮助。幸运的是，pg_trgm模块可以做到这一点。

• 
  
• http://www.depesz.com/2011/02/ 19 /等待9-1 - 更快 - likeilike /

I have a query with a number of test fields something like this:

SELECT * FROM some-table
  WHERE field1 ILIKE "%thing%"
     OR field2 ILIKE "%thing"
     OR field3 ILIKE "%thing";

The columns are pretty much all varchar(50) or thereabouts. Now I understand to improve performance I should index the fields upon which the search operates. Should I be considering replacing ILIKE with TSEARCH completely?

解决方案

A full text search setup is not identical to a "contains" like query. It stems words etc so you can match "cars" against "car".

If you really want a fast ILIKE then no standard database index or FTS will help. Fortunately, the pg_trgm module can do that.

• http://www.postgresql.org/docs/9.1/static/pgtrgm.html
• http://www.depesz.com/2011/02/19/waiting-for-9-1-faster-likeilike/

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