Re: Request to help on GIS Query improvement suggestion.

Your indexes and operators are not compatible. You have added a btree index
on md5 function result and are not using md5 in your query, and also using
LIKE operator not one of the supported ones. I believe it might use a btree
operator (plain value, not md5 result) if you are always searching for
"string starts with ____ but I don't know what it ends with" but you can't
possibly use a btree index where you are putting a wild card at the front.

https://www.postgresql.org/docs/9.5/indexes-types.html

a gist index operators supported-
https://www.postgresql.org/docs/9.5/gist-builtin-opclasses.html

Here's a whole page on full text search, it would be worth a read-
https://www.postgresql.org/docs/9.5/textsearch-tables.html#TEXTSEARCH-TABLES-INDEX