On 10/31/19 3:45 PM, Tom Lane wrote:
Andres Freund <and...@anarazel.de> writes:
On October 31, 2019 7:06:13 AM PDT, Andrzej Barszcz <abus...@gmail.com> wrote:
Any pros and cons ?
Depends on the actual way of implementing this proposal. Think we need more
details than what you idea here.
We've typically supposed that the cost of searching for duplicate
subexpressions would outweigh the benefits of sometimes finding them.
That is an important concern, but given how SQL does not make it
convenient to re-use partial results of calculations I think such
queries are quite common in real world workloads.
So if we can make it cheap enough I think that it is a worthwhile
optimization.
Andreas
