Are transactions in SQLAlchemy thread safe?

Question

I am developing a web app using SQLAlchemy\'s expression language, not its orm. I want to use multiple threads in my app, but I\'m not sure about thread safety. I am using

Answer 1

I think you are confusing atomicity with isolation.

Atomicity is usually handled through transactions and concerns integrity.

Isolation is about concurrent read/write to a database table (thus thread safety). For example: if you want to increment an int field of a table's record, you will have to select the record's field, increment the value and update it. If multiple threads are doing this concurrently the result will depend on the order of the reads/writes.

http://docs.sqlalchemy.org/en/latest/core/engines.html?highlight=isolation#engine-creation-api