Ensuring HNSW Indexes Exist

[techieAgnostic]

Hello.

Is there an idiomatic way to ensure tables and indexes exist?
:replace table { ... } can be used with an empty relation, however I cannot find an equivilent for ::hnsw.
My use case is with persistent storage, I would like to create indexes and tables if they do not already exist.

Thank you

[zh217]

We will work out a way. Note that :replace may not be what you want: it removes everything from the old relation if it exists!

Meanwhile you can try ... catch ... in the host language. If you use Python:

try:
    for s in schema:
        db.run(s)
except QueryException as e:
    if e.code == 'eval::stored_relation_conflict':
        logger.warning('Database already initialized.')
    else:
        raise

For indices (every kind of indices), look for e.code == 'tx::index_already_exists' instead.

[andrewbaxter]

I was looking for an equivalent for create if not exists for schema handling and I think this is the answer. Could this be added to the docs (for :create maybe?) and (Rust) is there an exported constant for "eval::stored_relation_conflict"?