Are db quesries asynchronous?

[Kesanov]

If I call ctx.run from multiple threads, will the database queries block each other ? For example:

class Main {
  import scala.concurrent.ExecutionContext.Implicits.global
  val ctx: Context = new PostgresJdbcContext[SnakeCase]( ... )

  def main(args: Array[String]): Unit = {
    // will a & b insert into database at the same time?
    val a = Future {ctx.run { .. insert into db .. }}
    val b = Future {ctx.run { .. insert into db .. }}
  }
}

What context should I use? PostgresJdbcContext or PostgresAsyncContext? Documentation does not really explain how do they differ and what is their purpose.

Is the maximum number of parallel queries equal to the size of connection pool?

What about the choice of ExecutionContext and usage of blocking { .. }.

[jilen]

PostgresAsyncContext use nio-based driver
While PostgresJdbcContext just use the blocking jdbc driver.
You'd better first do some research with postgresql-async, and if you decide to use it, be careful about this bug

[Kesanov]

Yes, jdbc is blocking, but is that an issue if quill uses pool of jdbc connections? So that when you wrap every call to database into future, you effectively can run `size of connection pool` parallel queries at the same time, no? 23. 2. 2018 2:19 AM, 2:19 AM, jilen <[email protected]> napsal/a:

…

`PostgresAsyncContext` use [nio-based driver](https://github.com/mauricio/postgresql-async/) While `PostgresJdbcContext` just use the blocking jdbc driver. You'd better first do some research with postgresql-async, and if you decide to use it, be careful about this [bug](mauricio/postgresql-async#241) -- You are receiving this because you authored the thread. Reply to this email directly or view it on GitHub: #1034 (comment)

[mosyp]

@Josef-Vonasek Yes, you can wrap scala execution context with fixed thread pool with number of threads equals to connection pool. The only restriction is to be careful with transactions since they need to be run in a single thread.
We have gitter channel for general-purpose questions https://gitter.im/getquill/quill