Discussion: https://postgr.es/m/CAMkU%3D1zxfA8_MGBW6sJMj54p8nPoe4bMb5LoG-rMYZVPq4j08Q%40mail.gmail.com
Author: Jeff Janes
trigram-based index searches for LIKE, ILIKE,
~ and ~* queries. Beginning in
PostgreSQL 14, these indexes also support
- the equality operator (simple comparison operators are not supported).
+ the equality operator (inequality operators are not supported).
Note that those indexes may not be as efficient as regular B-tree indexes
for equality operator.