Whenever I try to try to create a GIST index on text[] , I get the above error.

CREATE TABLE bar(f) AS VALUES (ARRAY['foo','bar','baz']); CREATE INDEX ON bar USING gist(f); ERROR: data type text[] has no default operator class for access method "gist" HINT: You must specify an operator class for the index or define a default operator class for the data type.

I'm trying to create an Exclusion Constraint on bar, so I need a GIST index.