Index Advisor continues to advise new indexes even after the recommended index is created

ADVISE will recommend a composite index with all the fields in the OR clause with a leading key. Then after you created the recommended index, and run ADVISE again, it will recommend another permutation of the same composite index.

ADVISE SELECT * FROM crm a
WHERE a.type='activity'
AND ( a.dept = 'iA88'
  OR a.region > '59416'
  OR a.priority = 'High'
  OR ( a.act_date BETWEEN '2018-01-01' AND '2018-08-31')
  OR a.event.location = 'Moscone Center'
  OR a.account.id = 'acc100')

{
"adviseResult": {
"current_indexes": [

{ "index_statement": "CREATE PRIMARY INDEX #primary ON `crm`", "keyspace_alias": "crm_a" }

],
"recommended_indexes": {
"indexes": [

{ "index_statement": "CREATE INDEX adv_type_event_location_dept_priority_account_id_act_date_region ON `crm`(`type`,`event`.`location`,`dept`,`priority`,`account`.`id`,`act_date`,`region`)", "index_statement_relative": "", "keyspace_alias": "crm_a", "query_context": "default:", "recommending_rule": "Index keys follow order of predicate types: 1. Common leading key for disjunction (2. equality/null/missing), 2. equality/null/missing, 4. not less than/between/not greater than, 5. less than/greater than." }

]
}
}
}