SDU Tools: Extract trigrams from strings in T-SQL
Fellow MVP Paul White and others have discussed the indexing of small segments of strings, to make fast indexes that I think are somewhat like full-text indexes but potentially more efficient. Three character substrings are common, and are known as trigrams.
I’ve experimented with these at a number of site and seen really interesting (good) results.
In our free SDU Tools for developers and DBAs, we added a table-valued function ExtractTrigrams to help with this. You can pass it a string, and it will pull it apart for you, and return the set of trigrams. This would make it much easier for you to experiment with these types of indexes.
You can see ExtractTrigrams in action here:
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2018-08-22