if JDBC is blocking, what is the benefit of using ...

# ktor

[waltermcq]

if JDBC is blocking, what is the benefit of using coroutines for async database calls through exposed w/ postgres?

[Dominaezzz]

Multithreaded database calls?

[napperley]

If the blocking DB stuff is done in a coroutine then only the coroutine is blocked, and any other coroutines that are running will remain unaffected (not blocked).

[mp]

blocking i/o blocks the thread, which will also block any coroutines that might be waiting to run on that thread.

[mp]

That's why you should wrap your blocking IO calls with withContext(<http://Dispatchers.IO|Dispatchers.IO>) (or other coroutine builders as needed)

[waltermcq]

@mp how does this compare with using newSuspendedTransaction(<http://Dispatchers.IO|Dispatchers.IO>) as seen here: https://github.com/JetBrains/Exposed/wiki/Transactions#working-with-coroutines

[mp]

Probably does just that under the hood.

[waltermcq]

thx