...and if we decide before the 5.0 release that we have enough information to change the default (#1), we can change it in a matter of minutes.
On Fri, May 12, 2023 at 11:28 AM Caleb Rackliffe <calebrackli...@gmail.com> wrote: > We don't need to know everything about SAI's performance profile to plan > and execute some small, reasonable things now for 5.0. I'm going to try to > summarize the least controversial package of ideas from the discussion > above. I've left out creating any new syntax. For example, I think CREATE > LOCAL INDEX, while explicit, is just not necessary. We don't use CREATE > LOCAL TABLE, although it has the same locality as our indexes. > > Okay, so the proposal for 5.0... > > 1.) Add a YAML option that specifies a default implementation for CREATE > INDEX, and make this the legacy 2i for now. No existing DDL breaks. We > don't have to commit to the absolute superiority of SAI. > 2.) Add USING...WITH... support to CREATE INDEX, so we don't have to go > to market using CREATE CUSTOM INDEX, which feels...not so polished. (The > backend for this already exists w/ CREATE CUSTOM INDEX.) > 3.) Leave in place but deprecate (client warnings could work?) CREATE > CUSTOM INDEX. Support the syntax for the foreseeable future. > > Can we live w/ this? > > I don't think any information about SAI we could possibly acquire before a > 5.0 release would affect the reasonableness of this much. > > > On Fri, May 12, 2023 at 10:54 AM Benedict <bened...@apache.org> wrote: > >> if we didn't have copious amounts of (not all public, I know, working on >> it) evidence >> >> >> If that’s the assumption on which this proposal is based, let’s discuss >> the evidence base first, as given the fundamentally different way they work >> (almost diametrically opposite), I would want to see a very high quality of >> evidence to support the claim. >> >> I don’t think we can resolve this conversation effectively until this >> question is settled. >> >> On 12 May 2023, at 16:19, Caleb Rackliffe <calebrackli...@gmail.com> >> wrote: >> >> >> > This creates huge headaches for everyone successfully using 2i today >> though, and SAI *is not* guaranteed to perform as well or better - it has a >> very different performance profile. >> >> We wouldn't have even advanced it to this point if we didn't have copious >> amounts of (not all public, I know, working on it) evidence it did for the >> vast majority of workloads. Having said that, I don't strongly agree that >> we should make it the default in 5.0, because performance isn't the only >> concern. (correctness, DDL back-compat, which we've sort of touched w/ the >> YAML default option, etc.) >> >> This conversation is now going in like 3 different directions, or at >> least 3 different "packages" of ideas, so there isn't even a single thing >> to vote on. Let me read through again and try to distill into something >> that we might be able to do so with... >> >> On Fri, May 12, 2023 at 7:56 AM Aleksey Yeshchenko <alek...@apple.com> >> wrote: >> >>> This. >>> >>> I would also consider adding CREATE LEGACY INDEX syntax as an alias for >>> today’s CREATE INDEX, the latter to be deprecated and (in very distant >>> future) removed. >>> >>> On 12 May 2023, at 13:14, Benedict <bened...@apache.org> wrote: >>> >>> This creates huge headaches for everyone successfully using 2i today >>> though, and SAI *is not* guaranteed to perform as well or better - it has a >>> very different performance profile. >>> >>> I think we should deprecate CREATE INDEX, and introduce new syntax >>> CREATE LOCAL INDEX to make clear that this is not a global index, and that >>> this should require the USING syntax to avoid this problem in future. >>> >>> We should report warnings to the client when CREATE INDEX is used, >>> indicating it is deprecated. >>> >>> >>>
