Provide an async implementation

[ggreg]

The current interface returns a generator of result rows and is mostly used synchronously. Leveraging async in Python 3 would allow to better utilize resources when managing parallel and concurrent queries.

One challenge is to keep compatibility with Python 2.7.

[jaredvacanti]

Is current best practice to use an asyncio executor when using presto-python-client in existing asynchronous applications? Are there alternative methods?

[ggreg]

We usually rely on a plain concurrent.futures.Executor to execute concurrent Presto queries.

Are you talking about using https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.loop.run_in_executor with a concurrent.futures.Executor to do Presto queries along async code?

We'd like to move to actually use async to support higher concurrent with a lower CPU and memory footprint for some application such as shadowing queries where we run the service with hundred of processes (which has a cost in memory usage as copy-on-write when forking processes tend to still copy a lot of pages with typical Python processes). There's also context switching between threads or processes and everything else that would be better with coroutines.

[dchimeno]

Is something planned related to support async execution?