Info dir
OpenCitations Meta assigns unique identifiers (OMIDs) to each entity. The numbering is tracked in Redis, where counters store the last assigned number for each entity type and supplier prefix.
When processing data, the system reads the current counter value, increments it, and uses that number for the new entity URI. For example, if the counter for br (bibliographic resource) with prefix 0610 is at 1000, the next entity will be https://w3id.org/oc/meta/br/06101001.
The info dir also tracks provenance snapshot counters. Each time an entity is modified, a new provenance snapshot is created with an incremental number.
Structure
Section titled “Structure”Redis keys follow this pattern:
- Entity counters:
{short_name}:{supplier_prefix}→ last assigned number - Provenance counters:
{short_name}:{supplier_prefix}:{entity_number}:se→ last snapshot number
Where short_name is one of: br, ra, ar, re, id.
When to use these scripts
Section titled “When to use these scripts”- After importing existing data: if you load RDF files from another source, you need to generate the info dir so that new entities don’t overlap with existing ones
- After a system failure: if Redis data is lost, you can rebuild it from the RDF files
- To verify consistency: check that Redis counters match the actual data in the RDF files