Vedis C/C++ API Reference - Transaction Manager.
Manually begin a write-transaction on the specified vedis handle.
Begin a write-transaction on the specified database handle. If a write-transaction has already been opened, this function is a no-op.
Tip: For maximum concurrency, it is preferable to let vedis start the transaction for you automatically. An automatic transaction is started each time upper-layers or client code request a store, delete or an append operation.
Vedis datastore handle.
VEDIS_READ_ONLY: Read-only database.
VEDIS_BUSY: Another thread or process have an exclusive lock on the database. In this case, the caller should wait until the lock holder relinquish it.
VEDIS_IOERR: OS specific error.
VEDIS_NOMEM: Out of memory (Unlikely scenario).
VEDIS_ABORT: Another thread have released the database handle.
For a human-readable error message, you can extract the database error log via vedis_config() with a configuration verb set to VEDIS_CONFIG_ERR_LOG.