Unlike Btree-based LIKE optimization, this works for non-left-anchored
search patterns. The effectiveness of the search depends on how many
trigrams can be extracted from the pattern. (The worst case, with no
trigrams, degrades to a full-table scan, so this isn't a panacea. But
it can be very useful.)
Alexander Korotkov, reviewed by Jan Urbanski
about best practice for including the module creation scripts: to wit
that you should suppress NOTICE messages. This avoids creating
regression failures by adding or removing comment lines in the module
scripts.
--------------------------------------
The pg_trgm contrib module provides functions and index classes
for determining the similarity of text based on trigram
matching.
