Dynamically setting __tablename__ for sharding in SQLAlchemy?

Question

In order to handle a growing database table, we are sharding on table name. So we could have database tables that are named like this:

table_md5one
table_md5         


        

Answer 1

In Augmenting the Base you find a way of using a custom Base class that can, for example, calculate the __tablename__ attribure dynamically:

class Base(object):
    @declared_attr
    def __tablename__(cls):
        return cls.__name__.lower()

The only problem here is that I don't know where your hash comes from, but this should give a good starting point.

If you require this algorithm not for all your tables but only for one you could just use the declared_attr on the table you are interested in sharding.