This repo contains the definition of the OMOP Common Data Model. It supports the 4 SQL technologies: Impala, Oracle, Postgres and SQL Server. For each, the DDL, constraints and indexes (if appropirate) are defined.
Versions are defined using tagging and versioning. Full versions (V6, 7 etc.) are released irregularly after a major strategy change or use case coverage. It will be issued during an OHDSI Symposium. Major version (V5.1, 5.2 etc.) are released half yearly (1-Jul and 1-Jan). Those versions are not guaranteed to be backward compatible. Minor versions (V5.1.1, V5.1.2 etc.) are released irregularly and often, and contain small hot fixes or backward compatible changes to the last Major Version.
See full CDM specification file on our Wiki.