id int(11) not_null auto_increment
cache_key varchar(64) not_null comment(Unique MD5 key)
user_query varchar(500) not_null comment(User question)
sql_query text not_null comment(Generated SQL query)
query_results longtext default null comment(JSON Results)
created_at datetime not_null comment(Creation date)
expires_at datetime not_null comment(Expiry date)
hit_count int(11) not_null default 0 comment(Number of uses)
interpretation text default null comment(Natural language interpretation)
entity_id int(10) unsigned default null
entity_type varchar(50) default null

--
primary id
unique cache_key cache_key
unique idx_cache_key cache_key
idx_expires expires_at
idx_hits hit_count
idx_entity entity_type entity_id

##
engine innodb
character_set utf8mb4
collate utf8mb4_unicode_ci