Promises. This was meant to provide more flexibility and control to the application developer and at the same time decrease the chance of buffering data unnecessarily. However this wasn’t useful for 99% of the use-cases and made simple tasks a little bit cumbersome. Also, the fact that it required using two different asynchronous constructs made it a little bit harder to grasp.
To make matters worse, in order to consume operational metadata about the columns in the result set, you would have to provide an additional callback, making the whole thing spiral a bit out of control, particularly when there were multiple result sets involved. In that case, you needed to create a shared context between the two functions in order to map data and metadata for each column in each result set.Continue reading