While it is certainly true that OP's "sequences" are kind of a database¹, it might be problematic to put them into a database². Of course, once this task is accomplished, it mainly depends on the database³ whether or not threading would help.

database

1. (general) A collection of (usually) organized information in a regular structure, usually but not necessarily in a machine-readable format accessible by a computer.
2. (computing) A set of tables in a database(1).
3. (computing) A software program for storing, retrieving and manipulating a database(1).