Regarding creation of gin index on column that has varchar datatype

Hi

Respected to PGDG GLOBAL TEAM

I am getting this error( ERROR: data type character varying has no default
operator class for access method "gin"
HINT: You must specify an operator class for the index or define a default
operator class for the data type ) while i try to create gin index on
vch_message column of slp01 table (CREATE INDEX ON slp01 using
gin(vch_message);)

vch_message column has lot of this info like
{"requestBody":{"firstName":"SALVATORE","lastName":"NAPOLITANO","email":"
remuda135(at)hotmail(dot)com","personID":"C48268","ClientSSN":"153520698","advisorPersonID":["10214","15270","15271","15272"]},"header":{"cache-control":"no-cache","content-type":"application/json","authorization":"Basic
Y3JlYXRlVXNlcnM6ZGFrdm5laXdvbjRpOWZqb3duY3VpMzRmdW4zOTQ4aGY=","accept":"application/json,
text/json, text/x-json, text/javascript, application/xml, text/xml"

NOTE:i have created pg_trgm based ginindex on this vch_message of slp01
table but it occupied more disk space hence i deleted trgm based gin index

please help in creating gin index on vch_message column of slp01 table

Regards
Durgamahesh Manne