Chapter 7. Practical Full-text Parsers

In the previous chapter we covered the basics of what a full-text parser plugin can do, how it works, and what is required to create one. In this chapter we will expand on this by going deeper into Boolean mode queries and creating full-text parsers that can be used in real-world applications.

Boolean parsers

The default, natural language, full-text search mode works well for inexperienced users who can simply describe what they want to find using plain English (or any other language) and let the system figure out, with complex statistical and probabilistic analysis, what rows are relevant to them. Other users want more control over what will be found. This is where Boolean search mode is used. It allows users to specify exactly which words must be present in all found rows and which words must not be present. It can search for "phrases"—sequences of words—for prefixes of words, and fine tune the importance of individual words for the result of a query...