SQLAlchemy, Serializable transactions isolation and retries in idiomatic Python way

Question

PostgreSQL and SQL defines a Serializable transaction isolation level. If you isolate transactions to this level, conflicting concurrent transactions abort and need retrying.

Answer 1

Postgres and Oracle conflict errors are marked as retryable by zope.sqlalchemy. Set your isolation level in the engine configuration and the transaction retry logic in pyramid_tm or Zope will work.