POC - determine best approach for programatically cleaning UUIDs from internal oai-pmh database

Purpose/Overview:
During the first request to inventory the oai-pmh retrieves UUIDs of all instances and stores them in the local mod-oai-pmh database. In the second and all consequent requests, the UUIDs are processed and removed by batches for every request. But if there is no consequent requests with resumption token, these ids are retained in the table indefinitely. Libraries may run the whole collection harvest (which we often refer to as an initial harvest) more frequently than once. It might lead to the situation that the module internal storage is overflown with data and deteriorate the performance.

Requirements/Scope:
1. Determine best approach to identify stale records in the mod-oai-pmh table:

• expiring resumptionToken (please see the commentto MODOAPMH-258)
• pre-define time
• configuration value
• other ways of storing UUIDs (should this be done in batches so we don't enter millions of records over and over again?)
• other options

2. Document the approach and review with the team
3. Create required user stories

Acceptance criteria:

• Proposed approach documented and reviewed with the team
• Required user stories created