I'm trying to run multiple simultaneous jobs in order to load around 700K record to a single BigQuery table. My code (Java) creates the schema from the records of is job, and updates the BigQuery schema, if needed.
Workflow is as follows:
- A single job creates the table and sets the (initial) schema.
- For each load job we create the schema from the records of the job. Then we pull the existing table schema from BigQuery, and if it's not a superset of the schema associated with the job, we update the schema with the new merged schema. The last part (starting from pulling the existing schema) is synced (using a lock) - only one job performs it at a time. The update of the schema is using the UPDATE method, and the lock is released only after the client update method returns.
I was expecting to avoid encountering schema update errors using this workflow. I'm assuming that once the client returns from the update job, then the table is updated, and that jobs that are in process can't be hurt from the schema update.
Nevertheless, I still get schema update errors from time to time. Is the update method atomic? How do I know when a schema was actually updated?
