Re: JIT compiling with LLVM v12

Hi,

On 2018-08-22 16:36:00 +0200, Peter Eisentraut wrote:
> I'm suspicious that we haven't had much feedback about this.  We've
> heard of one or two cases where LLVM broke a query outright, and that
> was fixed and that was a good result.  But we haven't heard anything
> about performance regressions.  Surely there must be some.  There hasn't
> been any discussion or further analysis of the default cost settings
> either.  I feel that we don't have enough information.

Yea. I don't think we'll get really good feedback before production
unfortunately :(


> I would like, however, that we make a decision one way or the other
> before the next beta.  I've been handwaving a bit to users not to rely
> on the current betas for performance testing because the defaults might
> change later.  That's bad either way.

I don't see particularly much benefit in deciding before beta,
personally.  What's making you think it'd be important to decide before?
Pretty fundamentally, it'll be a setting you don't know is effectively
on, for the forseeable future anyway?

Greetings,

Andres Freund