I store data for one year ,
the data is time and account based, while every possible query always referred to one account only.
what will better for query performance , separate all data to time based (month) index , or create multi index based on account number (for example modulo 100 on account number)
the data is
400M docs per month
about 100,000 accounts.
not all account equals by number of documents.
query can be done only on one account but on every possible date of the year.