I apologize that I had a wrong impression on the meeting time (I thought it should be on Thursday but it is Wednesday). I can follow up your meeting records if you have any.
-Rui On Tue, May 11, 2021 at 8:17 PM Botong Huang <[email protected]> wrote: > Hi all, > > This is a reminder that we are going to have our second discussion meeting > tomorrow at 10-11pm PST. Please find the link below, everyone is welcome to > join! > > Join Zoom Meeting > https://uci.zoom.us/j/91986206610 > < > https://www.google.com/url?q=https%3A%2F%2Fuci.zoom.us%2Fj%2F91986206610&sa=D&source=calendar&usd=2&usg=AOvVaw24sxPtI6hbukCSo3nlQsbn > > > > Meeting ID: 919 8620 6610 > One tap mobile > +16699006833 <(669)%20900-6833>,,91986206610# US (San Jose) > +12532158782 <(253)%20215-8782>,,91986206610# US (Tacoma) > > Dial by your location > +1 669 900 6833 <(669)%20900-6833> US (San Jose) > +1 253 215 8782 <(253)%20215-8782> US (Tacoma) > +1 346 248 7799 <(346)%20248-7799> US (Houston) > +1 301 715 8592 <(301)%20715-8592> US (Washington DC) > +1 312 626 6799 <(312)%20626-6799> US (Chicago) > +1 646 558 8656 <(646)%20558-8656> US (New York) > Meeting ID: 919 8620 6610 > Find your local number: https://uci.zoom.us/u/acyXcc43Cd > < > https://www.google.com/url?q=https%3A%2F%2Fuci.zoom.us%2Fu%2FacyXcc43Cd&sa=D&source=calendar&usd=2&usg=AOvVaw2W08kj_8hEx44dryeZlXb6 > > > > Join by Skype for Business > https://uci.zoom.us/skype/91986206610 > < > https://www.google.com/url?q=https%3A%2F%2Fuci.zoom.us%2Fskype%2F91986206610&sa=D&source=calendar&usd=2&usg=AOvVaw3w0M0YYbcjPyBXzNpyyk0Z > > > > Thanks, > Botong > > On Wed, May 5, 2021 at 9:55 AM Botong Huang <[email protected]> wrote: > > > Hi Stamatis and all, > > > > Thanks for the interest! Let's tentatively schedule the next meeting next > > Wednesday at May 12, 10pm-11pm PST then. Please let us know if there's > new > > needs showing up. > > > > Best, > > Botong > > > > On Sun, May 2, 2021 at 2:59 PM Stamatis Zampetakis <[email protected]> > > wrote: > > > >> Hello, > >> > >> I really regret missing the first meeting, sorry about that. I added my > >> preferences in the document. > >> I will make sure to attend the next one and help as much as I can. > >> > >> I didn't have the chance yet to go over the paper but will try to do it > >> before the next meeting. > >> > >> For me the following dates are more convenient than others so it would > be > >> nice if we could arrange it then. > >> > >> Thu, May 6, 10pm PST > >> Tue, May 12, 10pm PST > >> > >> Best, > >> Stamatis > >> > >> On Sat, May 1, 2021 at 9:42 PM Julian Hyde <[email protected]> wrote: > >> > >> > I have added my time preferences to the doc [1]. I am generally > >> > available any evening Mon - Thu. How about we meet Monday 10th May? > >> > > >> > Stamatis, Jesus, Given the complexity of this work, I would very much > >> > appreciate your insight, as experts in optimizer theory. Could one of > >> > you join the next meeting? Of course we should choose a time that > >> > works for everyone's schedule. > >> > > >> > Julian > >> > > >> > [1] > >> > > >> > https://docs.google.com/document/d/1wyNjB94uSGwHtVvGYDwaLlCghUJE-7aDLnCdKKXJN1o/edit?usp=sharing > >> > > >> > On Wed, Apr 28, 2021 at 9:32 AM Botong Huang <[email protected]> > wrote: > >> > > > >> > > We didn't record it, we will try to record the following meetings. > >> Please > >> > > add your time preference in the docs, so that we can find a meeting > >> time > >> > > that works for more people. > >> > > > >> > > Thanks, > >> > > Botong > >> > > > >> > > On Wed, Apr 28, 2021 at 12:23 AM Viliam Durina < > [email protected]> > >> > wrote: > >> > > > >> > > > Is there a recording available? > >> > > > Viliam > >> > > > > >> > > > On Wed, 28 Apr 2021 at 00:15, Botong Huang <[email protected]> > >> wrote: > >> > > > > >> > > > > Hi all, > >> > > > > > >> > > > > The meeting yesterday was fun and productive. As discussed, this > >> is > >> > the > >> > > > > call to schedule our second meeting. > >> > > > > > >> > > > > We encourage everyone to add their time preferences during > 05/01 - > >> > 05/15 > >> > > > > here: > >> > > > > > >> > > > > > >> > > > > >> > > >> > https://docs.google.com/document/d/1wyNjB94uSGwHtVvGYDwaLlCghUJE-7aDLnCdKKXJN1o/edit?usp=sharing > >> > > > > > >> > > > > Thanks, > >> > > > > Botong > >> > > > > > >> > > > > On Wed, Apr 21, 2021 at 5:19 PM Botong Huang <[email protected]> > >> > wrote: > >> > > > > > >> > > > > > Hi all, > >> > > > > > We've created a zoom meeting below for our meeting next Monday > >> > > > > > (9pm-10:30pm PST on 04/26). > >> > > > > > Talk to you all soon! > >> > > > > > > >> > > > > > Join Zoom Meeting > >> > > > > > https://uci.zoom.us/j/91279732686 > >> > > > > > < > >> > > > > > >> > > > > >> > > >> > https://www.google.com/url?q=https%3A%2F%2Fuci.zoom.us%2Fj%2F91279732686&sa=D&source=calendar&usd=2&usg=AOvVaw2C5LoOmCaSLWSi-YvMmsOE > >> > > > > > > >> > > > > > > >> > > > > > Meeting ID: 912 7973 2686 > >> > > > > > One tap mobile > >> > > > > > +16699006833 <(669)%20900-6833>,,91279732686# US (San Jose) > >> > > > > > +12532158782 <(253)%20215-8782>,,91279732686# US (Tacoma) > >> > > > > > > >> > > > > > Dial by your location > >> > > > > > +1 669 900 6833 <(669)%20900-6833> US (San Jose) > >> > > > > > +1 253 215 8782 <(253)%20215-8782> US (Tacoma) > >> > > > > > +1 346 248 7799 <(346)%20248-7799> US (Houston) > >> > > > > > +1 301 715 8592 <(301)%20715-8592> US (Washington DC) > >> > > > > > +1 312 626 6799 <(312)%20626-6799> US (Chicago) > >> > > > > > +1 646 558 8656 <(646)%20558-8656> US (New York) > >> > > > > > Meeting ID: 912 7973 2686 > >> > > > > > Find your local number: https://uci.zoom.us/u/aykHTkJBh > >> > > > > > < > >> > > > > > >> > > > > >> > > >> > https://www.google.com/url?q=https%3A%2F%2Fuci.zoom.us%2Fu%2FaykHTkJBh&sa=D&source=calendar&usd=2&usg=AOvVaw0y_V5CisCHRyt9wsXLa9UM > >> > > > > > > >> > > > > > > >> > > > > > Join by Skype for Business > >> > > > > > https://uci.zoom.us/skype/91279732686 > >> > > > > > < > >> > > > > > >> > > > > >> > > >> > https://www.google.com/url?q=https%3A%2F%2Fuci.zoom.us%2Fskype%2F91279732686&sa=D&source=calendar&usd=2&usg=AOvVaw3iQwsDViu3K7-Rb_Iy6Zsy > >> > > > > > > >> > > > > > > >> > > > > > > >> > > > > > Thanks, > >> > > > > > Botong > >> > > > > > > >> > > > > > On Tue, Apr 13, 2021 at 10:16 PM Botong Huang < > [email protected] > >> > > >> > > > wrote: > >> > > > > > > >> > > > > >> Hi all, > >> > > > > >> > >> > > > > >> According to the preferences collected, we are tentatively > >> > scheduling > >> > > > > our > >> > > > > >> meeting at 9pm-10:30pm PST on 04/26 Monday. > >> > > > > >> > >> > > > > >> We will give a presentation about Tempura, followed by a free > >> > > > > discussion. > >> > > > > >> > >> > > > > >> Please let us know if there are new other requests. Few days > >> > before > >> > > > > >> the meeting, I will send out a zoom meeting link. > >> > > > > >> > >> > > > > >> Thanks, > >> > > > > >> Botong > >> > > > > >> > >> > > > > >> On Wed, Apr 7, 2021 at 2:46 PM Botong Huang < > [email protected]> > >> > wrote: > >> > > > > >> > >> > > > > >>> Hi Julian and all, > >> > > > > >>> > >> > > > > >>> We've posted the Tempura code base below. Feel free to take > a > >> > quick > >> > > > > peek > >> > > > > >>> at the last five commits. > >> > > > > >>> > >> > > > > > >> > > >> > https://github.com/alibaba/cost-based-incremental-optimizer/commits/main > >> > > > > >>> > >> > > > > >>> I've also opened a Jira (CALCITE-4568 > >> > > > > >>> <https://issues.apache.org/jira/browse/CALCITE-4568>), > which > >> > will > >> > > > > serve > >> > > > > >>> as the umbrella Jira for the feature. > >> > > > > >>> > >> > > > > >>> In the meantime, we encourage everyone to enter the time > >> > preferences > >> > > > > for > >> > > > > >>> our first meeting here: > >> > > > > >>> > >> > > > > >>> > >> > > > > > >> > > > > >> > > >> > https://docs.google.com/document/d/1wyNjB94uSGwHtVvGYDwaLlCghUJE-7aDLnCdKKXJN1o/edit?usp=sharing > >> > > > > >>> > >> > > > > >>> Thanks, > >> > > > > >>> Botong > >> > > > > >>> > >> > > > > >>> On Mon, Apr 5, 2021 at 3:59 PM Julian Hyde < > >> > [email protected]> > >> > > > > >>> wrote: > >> > > > > >>> > >> > > > > >>>> I have added my time preferences to the doc. > >> > > > > >>>> > >> > > > > >>>> Before we meet, could you publish a PR for us to review? > >> > > > > >>>> > >> > > > > >>>> Initial discussions will need to be about architecture and > >> > > > high-level > >> > > > > >>>> design. So I would ask Calcite reviewers not to review the > PR > >> > > > > line-by-line > >> > > > > >>>> (or to leave comments in GitHub) but try to understand the > >> > design > >> > > > > >>>> holistically, and prepare questions/comments before the > >> meeting. > >> > > > > >>>> > >> > > > > >>>> Botong, Can you please create a Calcite JIRA case for this > >> task? > >> > > > JIRA > >> > > > > >>>> how we track long-running tasks such as this. > >> > > > > >>>> > >> > > > > >>>> Julian > >> > > > > >>>> > >> > > > > >>>> > >> > > > > >>>> > On Apr 3, 2021, at 5:15 PM, Botong Huang < > [email protected] > >> > > >> > > > wrote: > >> > > > > >>>> > > >> > > > > >>>> > Hi all, > >> > > > > >>>> > > >> > > > > >>>> > Apology for the delay. It took us some time to clean up > our > >> > code > >> > > > > base > >> > > > > >>>> and > >> > > > > >>>> > publicly release it (which will be out soon) for a quick > >> peek. > >> > > > > >>>> > > >> > > > > >>>> > We are ready to present our work. Let's schedule a time > >> for a > >> > Zoom > >> > > > > >>>> > meeting and discuss how to integrate Tempura into > Calcite. > >> > > > > >>>> > > >> > > > > >>>> > Since some of our team members are in China, we prefer > the > >> > time > >> > > > slot > >> > > > > >>>> of > >> > > > > >>>> > 7:00pm-11:30pm PST any day. I've added our time > preference > >> in > >> > the > >> > > > > >>>> shared > >> > > > > >>>> > doc below. > >> > > > > >>>> > > >> > > > > >>>> > >> > > > > > >> > > > > >> > > >> > https://docs.google.com/document/d/1wyNjB94uSGwHtVvGYDwaLlCghUJE-7aDLnCdKKXJN1o/edit?usp=sharing > >> > > > > >>>> > > >> > > > > >>>> > We encourage everyone to add their time preferences > (during > >> > > > > >>>> 04/15-04/30) in > >> > > > > >>>> > this doc. In a week or so, we will try to settle a time > >> that > >> > works > >> > > > > for > >> > > > > >>>> > most. > >> > > > > >>>> > > >> > > > > >>>> > Thanks, > >> > > > > >>>> > Botong > >> > > > > >>>> > > >> > > > > >>>> > On Sat, Jan 30, 2021 at 9:19 PM Botong Huang < > >> > [email protected]> > >> > > > > >>>> wrote: > >> > > > > >>>> > > >> > > > > >>>> >> Hi Julian and Rui, > >> > > > > >>>> >> > >> > > > > >>>> >> Sounds good to us. Please give us some time to prepare > >> some > >> > > > slides > >> > > > > >>>> for the > >> > > > > >>>> >> meeting. > >> > > > > >>>> >> > >> > > > > >>>> >> I've created a doc below for discussion. Please feel > free > >> to > >> > add > >> > > > > >>>> more in > >> > > > > >>>> >> here: > >> > > > > >>>> >> > >> > > > > >>>> >> > >> > > > > >>>> > >> > > > > > >> > > > > >> > > >> > https://docs.google.com/document/d/1wyNjB94uSGwHtVvGYDwaLlCghUJE-7aDLnCdKKXJN1o/edit?usp=sharing > >> > > > > >>>> >> > >> > > > > >>>> >> Thanks, > >> > > > > >>>> >> Botong > >> > > > > >>>> >> > >> > > > > >>>> >> On Thu, Jan 28, 2021 at 11:18 AM Julian Hyde < > >> > > > > [email protected] > >> > > > > >>>> > > >> > > > > >>>> >> wrote: > >> > > > > >>>> >> > >> > > > > >>>> >>> PS The “editable doc” that Rui refers to is also a good > >> > idea. I > >> > > > > >>>> think we > >> > > > > >>>> >>> should create it to continue discussion after the first > >> > meeting. > >> > > > > >>>> >>> > >> > > > > >>>> >>> Julian > >> > > > > >>>> >>> > >> > > > > >>>> >>>> On Jan 28, 2021, at 11:16 AM, Julian Hyde < > >> > > > > [email protected]> > >> > > > > >>>> >>> wrote: > >> > > > > >>>> >>>> > >> > > > > >>>> >>>> I think good next steps would be a PR and a meeting. > >> The > >> > PR > >> > > > will > >> > > > > >>>> allow > >> > > > > >>>> >>> us to read the code, but I think we should do the first > >> > round of > >> > > > > >>>> questions > >> > > > > >>>> >>> at the meeting. The meeting could perhaps start with a > >> > > > > >>>> presentation of the > >> > > > > >>>> >>> paper (do you have some slides you are planning to > >> present > >> > at > >> > > > > VLDB, > >> > > > > >>>> >>> Botong?) and then move on to questions about the > >> concepts, > >> > which > >> > > > > >>>> >>> alternatives were considered, and how the concepts map > >> onto > >> > > > other > >> > > > > >>>> current > >> > > > > >>>> >>> and future concepts in calcite. > >> > > > > >>>> >>>> > >> > > > > >>>> >>>> I don’t think we should start “reviewing” the PR > >> > line-by-line > >> > > > at > >> > > > > >>>> this > >> > > > > >>>> >>> point. We need to understand the high-level concepts > and > >> > design > >> > > > > >>>> choices. If > >> > > > > >>>> >>> we start reviewing the PR we will get lost in the > >> details. > >> > > > > >>>> >>>> > >> > > > > >>>> >>>> I know that integrating a major change is hard; I > doubt > >> > that we > >> > > > > >>>> will be > >> > > > > >>>> >>> able to integrate everything, but we can build > >> understanding > >> > > > about > >> > > > > >>>> where > >> > > > > >>>> >>> calcite needs to go, and I hope integrate a good amount > >> of > >> > code > >> > > > to > >> > > > > >>>> help us > >> > > > > >>>> >>> get there. > >> > > > > >>>> >>>> > >> > > > > >>>> >>>> As I said before, after the integration I would like > >> > people to > >> > > > be > >> > > > > >>>> able > >> > > > > >>>> >>> to experiment with it and use it in their production > >> > systems. > >> > > > > That > >> > > > > >>>> way, it > >> > > > > >>>> >>> will not be an experiment that withers, but a feature > set > >> > > > > >>>> integrates with > >> > > > > >>>> >>> other calcite features and gets stronger over time. > >> > > > > >>>> >>>> > >> > > > > >>>> >>>> Julian > >> > > > > >>>> >>>> > >> > > > > >>>> >>>>> On Jan 28, 2021, at 10:54 AM, Rui Wang < > >> > [email protected]> > >> > > > > >>>> wrote: > >> > > > > >>>> >>>>> > >> > > > > >>>> >>>>> For me to participate in the discussion for the > above > >> > > > > questions, > >> > > > > >>>> I > >> > > > > >>>> >>> will > >> > > > > >>>> >>>>> need to read a lot more to know relevant context and > >> > likely > >> > > > ask > >> > > > > >>>> lots of > >> > > > > >>>> >>>>> questions :-). A editable doc is probably good for > >> > questions > >> > > > > and > >> > > > > >>>> back > >> > > > > >>>> >>> and > >> > > > > >>>> >>>>> forward discussion. > >> > > > > >>>> >>>>> > >> > > > > >>>> >>>>> > >> > > > > >>>> >>>>> -Rui > >> > > > > >>>> >>>>> > >> > > > > >>>> >>>>>>> On Thu, Jan 28, 2021 at 10:50 AM Rui Wang < > >> > > > > [email protected] > >> > > > > >>>> > > >> > > > > >>>> >>> wrote: > >> > > > > >>>> >>>>>> > >> > > > > >>>> >>>>>> I am also happy to help push this work into Calcite > >> > (review > >> > > > > code > >> > > > > >>>> and > >> > > > > >>>> >>> doc, > >> > > > > >>>> >>>>>> etc.). > >> > > > > >>>> >>>>>> > >> > > > > >>>> >>>>>> While you can share your code so people can have > more > >> > idea > >> > > > how > >> > > > > >>>> it is > >> > > > > >>>> >>>>>> implemented, I think it would be also nice to have a > >> doc > >> > to > >> > > > > >>>> discuss > >> > > > > >>>> >>> open > >> > > > > >>>> >>>>>> questions above. Some points that I copy those to > >> here: > >> > > > > >>>> >>>>>> > >> > > > > >>>> >>>>>> 1. Can this solution be compatible with existing > >> > solutions in > >> > > > > >>>> Calcite > >> > > > > >>>> >>>>>> Streaming, materialized view maintenance, and > >> multi-query > >> > > > > >>>> optimization > >> > > > > >>>> >>>>>> (Sigma and Delta relational operators, lattice, and > >> Spool > >> > > > > >>>> operator), > >> > > > > >>>> >>>>>> 2. Did you find that you needed two separate cost > >> models > >> > - > >> > > > one > >> > > > > >>>> for > >> > > > > >>>> >>> “view > >> > > > > >>>> >>>>>> maintenance” and another for “user queries” - since > >> the > >> > > > > >>>> objectives of > >> > > > > >>>> >>> each > >> > > > > >>>> >>>>>> activity are so different? > >> > > > > >>>> >>>>>> 3. whether this work will hasten the arrival of > >> > > > multi-objective > >> > > > > >>>> >>> parametric > >> > > > > >>>> >>>>>> query optimization [1] in Calcite. > >> > > > > >>>> >>>>>> 4. probably SQL shell support. > >> > > > > >>>> >>>>>> > >> > > > > >>>> >>>>>> > >> > > > > >>>> >>>>>> [1]: > >> > > > > >>>> >>>>>> > >> > > > > >>>> >>> > >> > > > > >>>> > >> > > > > > >> > > > > >> > > >> > https://cacm.acm.org/magazines/2017/10/221322-multi-objective-parametric-query-optimization/fulltext > >> > > > > >>>> >>>>>> > >> > > > > >>>> >>>>>> > >> > > > > >>>> >>>>>> -Rui > >> > > > > >>>> >>>>>> > >> > > > > >>>> >>>>>> > >> > > > > >>>> >>>>>> > >> > > > > >>>> >>>>>>> On Wed, Jan 27, 2021 at 6:52 PM Albert < > >> > [email protected]> > >> > > > > >>>> wrote: > >> > > > > >>>> >>>>>>> > >> > > > > >>>> >>>>>>> it would be very nice to see a POC of your work. > >> > > > > >>>> >>>>>>> > >> > > > > >>>> >>>>>>> > >> > > > > >>>> >>>>>>>> On Thu, Jan 28, 2021 at 10:21 AM Botong Huang < > >> > > > > >>>> [email protected]> > >> > > > > >>>> >>> wrote: > >> > > > > >>>> >>>>>>> > >> > > > > >>>> >>>>>>>> Hi Julian, > >> > > > > >>>> >>>>>>>> > >> > > > > >>>> >>>>>>>> Just wondering if there are any updates? We are > >> > wondering > >> > > > if > >> > > > > it > >> > > > > >>>> >>> would > >> > > > > >>>> >>>>>>> help > >> > > > > >>>> >>>>>>>> to post our code for a quick preview. > >> > > > > >>>> >>>>>>>> > >> > > > > >>>> >>>>>>>> Thanks, > >> > > > > >>>> >>>>>>>> Botong > >> > > > > >>>> >>>>>>>> > >> > > > > >>>> >>>>>>>> On Fri, Jan 1, 2021 at 11:04 AM Botong Huang < > >> > > > > [email protected] > >> > > > > >>>> > > >> > > > > >>>> >>> wrote: > >> > > > > >>>> >>>>>>>> > >> > > > > >>>> >>>>>>>>> Hi Julian, > >> > > > > >>>> >>>>>>>>> > >> > > > > >>>> >>>>>>>>> Thanks for your interest! Sure let's figure out a > >> plan > >> > > > that > >> > > > > >>>> best > >> > > > > >>>> >>>>>>> benefits > >> > > > > >>>> >>>>>>>>> the community. Here are some clarifications that > >> > hopefully > >> > > > > >>>> answer > >> > > > > >>>> >>> your > >> > > > > >>>> >>>>>>>>> questions. > >> > > > > >>>> >>>>>>>>> > >> > > > > >>>> >>>>>>>>> In our work (Tempura), users specify the set of > >> time > >> > > > points > >> > > > > to > >> > > > > >>>> >>>>>>> consider > >> > > > > >>>> >>>>>>>>> running and a cost function that expresses users' > >> > > > preference > >> > > > > >>>> over > >> > > > > >>>> >>>>>>> time, > >> > > > > >>>> >>>>>>>>> Tempura will generate the best incremental plan > >> that > >> > > > > >>>> minimizes the > >> > > > > >>>> >>>>>>>> overall > >> > > > > >>>> >>>>>>>>> cost function. > >> > > > > >>>> >>>>>>>>> > >> > > > > >>>> >>>>>>>>> In this incremental plan, the sub-plans at > >> different > >> > time > >> > > > > >>>> points > >> > > > > >>>> >>> can > >> > > > > >>>> >>>>>>> be > >> > > > > >>>> >>>>>>>>> different from each other, as opposed to > identical > >> > plans > >> > > > in > >> > > > > >>>> all > >> > > > > >>>> >>> delta > >> > > > > >>>> >>>>>>>> runs > >> > > > > >>>> >>>>>>>>> as in streaming or IVM. As mentioned in $2.1 of > the > >> > > > Tempura > >> > > > > >>>> paper, > >> > > > > >>>> >>> we > >> > > > > >>>> >>>>>>> can > >> > > > > >>>> >>>>>>>>> mimic the current streaming implementation by > >> > specifying > >> > > > two > >> > > > > >>>> >>> (logical) > >> > > > > >>>> >>>>>>>> time > >> > > > > >>>> >>>>>>>>> points in Tempura, representing the initial run > and > >> > later > >> > > > > >>>> delta > >> > > > > >>>> >>> runs > >> > > > > >>>> >>>>>>>>> respectively. In general, note that Tempura > >> supports > >> > > > various > >> > > > > >>>> form > >> > > > > >>>> >>> of > >> > > > > >>>> >>>>>>>>> incremental computing, not only the small-delta > >> > > > append-only > >> > > > > >>>> data > >> > > > > >>>> >>>>>>> model in > >> > > > > >>>> >>>>>>>>> streaming systems. That's why we believe Tempura > >> > subsumes > >> > > > > the > >> > > > > >>>> >>> current > >> > > > > >>>> >>>>>>>>> streaming support, as well as any IVM > >> implementations. > >> > > > > >>>> >>>>>>>>> > >> > > > > >>>> >>>>>>>>> About the cost model, we did not come up with a > >> > seperate > >> > > > > cost > >> > > > > >>>> >>> model, > >> > > > > >>>> >>>>>>> but > >> > > > > >>>> >>>>>>>>> rather extended the existing one. Similar to > >> > > > multi-objective > >> > > > > >>>> >>>>>>>> optimization, > >> > > > > >>>> >>>>>>>>> costs incurred at different time points are > >> considered > >> > > > > >>>> different > >> > > > > >>>> >>>>>>>>> dimensions. Tempura lets users supply a function > >> that > >> > > > > >>>> converts this > >> > > > > >>>> >>>>>>> cost > >> > > > > >>>> >>>>>>>>> vector into a final cost. So under this function, > >> any > >> > two > >> > > > > >>>> >>> incremental > >> > > > > >>>> >>>>>>>> plans > >> > > > > >>>> >>>>>>>>> are still comparable and there is an overall > >> optimum. > >> > I > >> > > > > guess > >> > > > > >>>> we > >> > > > > >>>> >>> can > >> > > > > >>>> >>>>>>> go > >> > > > > >>>> >>>>>>>>> down the route of multi-objective parametric > query > >> > > > > >>>> optimization > >> > > > > >>>> >>>>>>> instead > >> > > > > >>>> >>>>>>>> if > >> > > > > >>>> >>>>>>>>> there is a need. > >> > > > > >>>> >>>>>>>>> > >> > > > > >>>> >>>>>>>>> Next on materialized views and multi-query > >> > optimization, > >> > > > > >>>> since our > >> > > > > >>>> >>>>>>>>> multi-time-point plan naturally involves > >> materializing > >> > > > > >>>> intermediate > >> > > > > >>>> >>>>>>>> results > >> > > > > >>>> >>>>>>>>> for later time points, we need to solve the > >> problem of > >> > > > > >>>> choosing > >> > > > > >>>> >>>>>>>>> materializations and include the cost of saving > and > >> > > > reusing > >> > > > > >>>> the > >> > > > > >>>> >>>>>>>>> materializations when costing and comparing > plans. > >> We > >> > > > > >>>> borrowed the > >> > > > > >>>> >>>>>>>>> multi-query optimization techniques to solve this > >> > problem > >> > > > > even > >> > > > > >>>> >>> though > >> > > > > >>>> >>>>>>> we > >> > > > > >>>> >>>>>>>>> are looking at a single query. As a result, we > >> think > >> > our > >> > > > > work > >> > > > > >>>> is > >> > > > > >>>> >>>>>>>> orthogonal > >> > > > > >>>> >>>>>>>>> to Calcite's facilities around utilizing existing > >> > views, > >> > > > > >>>> lattice > >> > > > > >>>> >>> etc. > >> > > > > >>>> >>>>>>> We > >> > > > > >>>> >>>>>>>> do > >> > > > > >>>> >>>>>>>>> feel that the multi-query optimization component > >> can > >> > be > >> > > > > >>>> adopted to > >> > > > > >>>> >>>>>>> wider > >> > > > > >>>> >>>>>>>>> use, but probably need more suggestions from the > >> > > > community. > >> > > > > >>>> >>>>>>>>> > >> > > > > >>>> >>>>>>>>> Lastly, our current implementation is set up in > >> java > >> > code, > >> > > > > it > >> > > > > >>>> >>> should > >> > > > > >>>> >>>>>>> be > >> > > > > >>>> >>>>>>>>> straightforward to hook it up with SQL shell. > >> > > > > >>>> >>>>>>>>> > >> > > > > >>>> >>>>>>>>> Thanks, > >> > > > > >>>> >>>>>>>>> Botong > >> > > > > >>>> >>>>>>>>> > >> > > > > >>>> >>>>>>>>> On Mon, Dec 28, 2020 at 6:44 PM Julian Hyde < > >> > > > > >>>> >>> [email protected]> > >> > > > > >>>> >>>>>>>>> wrote: > >> > > > > >>>> >>>>>>>>> > >> > > > > >>>> >>>>>>>>>> Botong, > >> > > > > >>>> >>>>>>>>>> > >> > > > > >>>> >>>>>>>>>> This is very exciting; congratulations on this > >> > research, > >> > > > > and > >> > > > > >>>> thank > >> > > > > >>>> >>>>>>> you > >> > > > > >>>> >>>>>>>>>> for contributing it back to Calcite. > >> > > > > >>>> >>>>>>>>>> > >> > > > > >>>> >>>>>>>>>> The research touches several areas in Calcite: > >> > streaming, > >> > > > > >>>> >>>>>>> materialized > >> > > > > >>>> >>>>>>>>>> view maintenance, and multi-query optimization. > >> As we > >> > > > have > >> > > > > >>>> already > >> > > > > >>>> >>>>>>> some > >> > > > > >>>> >>>>>>>>>> solutions in those areas (Sigma and Delta > >> relational > >> > > > > >>>> operators, > >> > > > > >>>> >>>>>>> lattice, > >> > > > > >>>> >>>>>>>>>> and Spool operator), it will be interesting to > see > >> > > > whether > >> > > > > >>>> we can > >> > > > > >>>> >>>>>>> make > >> > > > > >>>> >>>>>>>> them > >> > > > > >>>> >>>>>>>>>> compatible, or whether one concept can subsume > >> > others. > >> > > > > >>>> >>>>>>>>>> > >> > > > > >>>> >>>>>>>>>> Your work differs from streaming queries in that > >> your > >> > > > > >>>> relations > >> > > > > >>>> >>> are > >> > > > > >>>> >>>>>>> used > >> > > > > >>>> >>>>>>>>>> by “external” user queries, whereas in pure > >> streaming > >> > > > > >>>> queries, the > >> > > > > >>>> >>>>>>> only > >> > > > > >>>> >>>>>>>>>> activity is the change propagation. Did you find > >> > that you > >> > > > > >>>> needed > >> > > > > >>>> >>> two > >> > > > > >>>> >>>>>>>>>> separate cost models - one for “view > maintenance” > >> and > >> > > > > >>>> another for > >> > > > > >>>> >>>>>>> “user > >> > > > > >>>> >>>>>>>>>> queries” - since the objectives of each activity > >> are > >> > so > >> > > > > >>>> different? > >> > > > > >>>> >>>>>>>>>> > >> > > > > >>>> >>>>>>>>>> I wonder whether this work will hasten the > >> arrival of > >> > > > > >>>> >>> multi-objective > >> > > > > >>>> >>>>>>>>>> parametric query optimization [1] in Calcite. > >> > > > > >>>> >>>>>>>>>> > >> > > > > >>>> >>>>>>>>>> I will make time over the next few days to read > >> and > >> > > > digest > >> > > > > >>>> your > >> > > > > >>>> >>>>>>> paper. > >> > > > > >>>> >>>>>>>>>> Then I expect that we will have a back-and-forth > >> > process > >> > > > to > >> > > > > >>>> create > >> > > > > >>>> >>>>>>>>>> something that will be useful for the broader > >> > community. > >> > > > > >>>> >>>>>>>>>> > >> > > > > >>>> >>>>>>>>>> One thing will be particularly useful: making > this > >> > > > > >>>> functionality > >> > > > > >>>> >>>>>>>>>> available from a SQL shell, so that people can > >> > experiment > >> > > > > >>>> with > >> > > > > >>>> >>> this > >> > > > > >>>> >>>>>>>>>> functionality without writing Java code or > >> setting up > >> > > > > complex > >> > > > > >>>> >>>>>>> databases > >> > > > > >>>> >>>>>>>> and > >> > > > > >>>> >>>>>>>>>> metadata. I have in mind something like the > simple > >> > DDL > >> > > > > >>>> operations > >> > > > > >>>> >>>>>>> that > >> > > > > >>>> >>>>>>>> are > >> > > > > >>>> >>>>>>>>>> available in Calcite’s ’server’ module. I wonder > >> > whether > >> > > > we > >> > > > > >>>> could > >> > > > > >>>> >>>>>>> devise > >> > > > > >>>> >>>>>>>>>> some kind of SQL syntax for a “multi-query”. > >> > > > > >>>> >>>>>>>>>> > >> > > > > >>>> >>>>>>>>>> Julian > >> > > > > >>>> >>>>>>>>>> > >> > > > > >>>> >>>>>>>>>> [1] > >> > > > > >>>> >>>>>>>>>> > >> > > > > >>>> >>>>>>>> > >> > > > > >>>> >>>>>>> > >> > > > > >>>> >>> > >> > > > > >>>> > >> > > > > > >> > > > > >> > > >> > https://cacm.acm.org/magazines/2017/10/221322-multi-objective-parametric-query-optimization/fulltext > >> > > > > >>>> >>>>>>>>>> > >> > > > > >>>> >>>>>>>>>> > >> > > > > >>>> >>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>> On Dec 23, 2020, at 8:55 PM, Botong Huang < > >> > > > > [email protected] > >> > > > > >>>> > > >> > > > > >>>> >>>>>>> wrote: > >> > > > > >>>> >>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>> Thanks Aron for pointing this out. To see the > >> > figure, > >> > > > > please > >> > > > > >>>> >>> refer > >> > > > > >>>> >>>>>>> to > >> > > > > >>>> >>>>>>>>>> Fig > >> > > > > >>>> >>>>>>>>>>> 3(a) in our paper: > >> > > > > >>>> >>>>>>>>>> > >> > https://kai-zeng.github.io/papers/tempura-vldb2021.pdf > >> > > > > >>>> >>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>> Best, > >> > > > > >>>> >>>>>>>>>>> Botong > >> > > > > >>>> >>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>> On Wed, Dec 23, 2020 at 7:20 PM JiaTao Tao < > >> > > > > >>>> [email protected]> > >> > > > > >>>> >>>>>>>> wrote: > >> > > > > >>>> >>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>> Seems interesting, the pic can not be seen in > >> the > >> > mail, > >> > > > > >>>> may you > >> > > > > >>>> >>>>>>> open > >> > > > > >>>> >>>>>>>> a > >> > > > > >>>> >>>>>>>>>> JIRA > >> > > > > >>>> >>>>>>>>>>>> for this, people who are interested in this > can > >> > > > subscribe > >> > > > > >>>> to the > >> > > > > >>>> >>>>>>>> JIRA? > >> > > > > >>>> >>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>> Regards! > >> > > > > >>>> >>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>> Aron Tao > >> > > > > >>>> >>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>> Botong Huang <[email protected]> > 于2020年12月24日周四 > >> > > > > 上午3:18写道： > >> > > > > >>>> >>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>>> Hi all, > >> > > > > >>>> >>>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>>> This is a proposal to extend the Calcite > >> optimizer > >> > > > into > >> > > > > a > >> > > > > >>>> >>> general > >> > > > > >>>> >>>>>>>>>>>>> incremental query optimizer, based on our > >> research > >> > > > paper > >> > > > > >>>> >>>>>>> published > >> > > > > >>>> >>>>>>>> in > >> > > > > >>>> >>>>>>>>>>>> VLDB > >> > > > > >>>> >>>>>>>>>>>>> 2021: > >> > > > > >>>> >>>>>>>>>>>>> Tempura: a general cost-based optimizer > >> framework > >> > for > >> > > > > >>>> >>> incremental > >> > > > > >>>> >>>>>>>> data > >> > > > > >>>> >>>>>>>>>>>>> processing > >> > > > > >>>> >>>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>>> We also have a demo in SIGMOD 2020 > illustrating > >> > how > >> > > > > >>>> Alibaba’s > >> > > > > >>>> >>>>>>> data > >> > > > > >>>> >>>>>>>>>>>>> warehouse is planning to use this incremental > >> > query > >> > > > > >>>> optimizer > >> > > > > >>>> >>> to > >> > > > > >>>> >>>>>>>>>>>> alleviate > >> > > > > >>>> >>>>>>>>>>>>> cluster-wise resource skewness: > >> > > > > >>>> >>>>>>>>>>>>> Grosbeak: A Data Warehouse Supporting > >> > Resource-Aware > >> > > > > >>>> >>> Incremental > >> > > > > >>>> >>>>>>>>>>>> Computing > >> > > > > >>>> >>>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>>> To our best knowledge, this is the first > >> general > >> > > > > >>>> cost-based > >> > > > > >>>> >>>>>>>>>> incremental > >> > > > > >>>> >>>>>>>>>>>>> optimizer that can find the best plan across > >> > multiple > >> > > > > >>>> families > >> > > > > >>>> >>> of > >> > > > > >>>> >>>>>>>>>>>>> incremental computing methods, including IVM, > >> > > > Streaming, > >> > > > > >>>> >>>>>>> DBToaster, > >> > > > > >>>> >>>>>>>>>> etc. > >> > > > > >>>> >>>>>>>>>>>>> Experiments (in the paper) shows that the > >> > generated > >> > > > best > >> > > > > >>>> plan > >> > > > > >>>> >>> is > >> > > > > >>>> >>>>>>>>>>>>> consistently much better than the plans from > >> each > >> > > > > >>>> individual > >> > > > > >>>> >>>>>>> method > >> > > > > >>>> >>>>>>>>>>>> alone. > >> > > > > >>>> >>>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>>> In general, incremental query planning is > >> central > >> > to > >> > > > > >>>> database > >> > > > > >>>> >>>>>>> view > >> > > > > >>>> >>>>>>>>>>>>> maintenance and stream processing systems, > and > >> are > >> > > > being > >> > > > > >>>> >>> adopted > >> > > > > >>>> >>>>>>> in > >> > > > > >>>> >>>>>>>>>>>> active > >> > > > > >>>> >>>>>>>>>>>>> databases, resumable query execution, > >> approximate > >> > > > query > >> > > > > >>>> >>>>>>> processing, > >> > > > > >>>> >>>>>>>>>> etc. > >> > > > > >>>> >>>>>>>>>>>> We > >> > > > > >>>> >>>>>>>>>>>>> are hoping that this feature can help > widening > >> the > >> > > > > >>>> spectrum of > >> > > > > >>>> >>>>>>>>>> Calcite, > >> > > > > >>>> >>>>>>>>>>>>> solicit more use cases and adoption of > Calcite. > >> > > > > >>>> >>>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>>> Below is a brief description of the technical > >> > details. > >> > > > > >>>> Please > >> > > > > >>>> >>>>>>> refer > >> > > > > >>>> >>>>>>>> to > >> > > > > >>>> >>>>>>>>>>>> the > >> > > > > >>>> >>>>>>>>>>>>> Tempura paper for more details. We are also > >> > working > >> > > > on a > >> > > > > >>>> >>> journal > >> > > > > >>>> >>>>>>>>>> version > >> > > > > >>>> >>>>>>>>>>>> of > >> > > > > >>>> >>>>>>>>>>>>> the paper with more implementation details. > >> > > > > >>>> >>>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>>> Currently the query plan generated by Calcite > >> is > >> > meant > >> > > > > to > >> > > > > >>>> be > >> > > > > >>>> >>>>>>>> executed > >> > > > > >>>> >>>>>>>>>>>>> altogether at once. In the proposal, > Calcite’s > >> > memo > >> > > > will > >> > > > > >>>> be > >> > > > > >>>> >>>>>>> extended > >> > > > > >>>> >>>>>>>>>> with > >> > > > > >>>> >>>>>>>>>>>>> temporal information so that it is capable of > >> > > > generating > >> > > > > >>>> >>>>>>> incremental > >> > > > > >>>> >>>>>>>>>>>> plans > >> > > > > >>>> >>>>>>>>>>>>> that include multiple sub-plans to execute at > >> > > > different > >> > > > > >>>> time > >> > > > > >>>> >>>>>>> points. > >> > > > > >>>> >>>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>>> The main idea is to view each table as one > that > >> > > > changes > >> > > > > >>>> over > >> > > > > >>>> >>> time > >> > > > > >>>> >>>>>>>>>> (Time > >> > > > > >>>> >>>>>>>>>>>>> Varying Relations (TVR)). To achieve that we > >> > > > introduced > >> > > > > >>>> >>>>>>> TvrMetaSet > >> > > > > >>>> >>>>>>>>>> into > >> > > > > >>>> >>>>>>>>>>>>> Calcite’s memo besides RelSet and RelSubset > to > >> > track > >> > > > > >>>> related > >> > > > > >>>> >>>>>>> RelSets > >> > > > > >>>> >>>>>>>>>> of a > >> > > > > >>>> >>>>>>>>>>>>> changing table (e.g. snapshot of the table at > >> > certain > >> > > > > >>>> time, > >> > > > > >>>> >>>>>>> delta of > >> > > > > >>>> >>>>>>>>>> the > >> > > > > >>>> >>>>>>>>>>>>> table between two time points, etc.). > >> > > > > >>>> >>>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>>> [image: image.png] > >> > > > > >>>> >>>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>>> For example in the above figure, each > vertical > >> > line > >> > > > is a > >> > > > > >>>> >>>>>>> TvrMetaSet > >> > > > > >>>> >>>>>>>>>>>>> representing a TVR (S, R, S left outer join > R, > >> > etc.). > >> > > > > >>>> >>> Horizontal > >> > > > > >>>> >>>>>>>> lines > >> > > > > >>>> >>>>>>>>>>>>> represent time. Each black dot in the grid > is a > >> > > > RelSet. > >> > > > > >>>> Users > >> > > > > >>>> >>> can > >> > > > > >>>> >>>>>>>>>> write > >> > > > > >>>> >>>>>>>>>>>> TVR > >> > > > > >>>> >>>>>>>>>>>>> Rewrite Rules to describe valid > transformations > >> > > > between > >> > > > > >>>> these > >> > > > > >>>> >>>>>>> dots. > >> > > > > >>>> >>>>>>>>>> For > >> > > > > >>>> >>>>>>>>>>>>> example, the blues lines are inter-TVR rules > >> that > >> > > > > >>>> describe how > >> > > > > >>>> >>> to > >> > > > > >>>> >>>>>>>>>> compute > >> > > > > >>>> >>>>>>>>>>>>> certain RelSet of a TVR from RelSets of other > >> > TVRs. > >> > > > The > >> > > > > >>>> red > >> > > > > >>>> >>> lines > >> > > > > >>>> >>>>>>>> are > >> > > > > >>>> >>>>>>>>>>>>> intra-TVR rules that describe transformations > >> > within a > >> > > > > >>>> TVR. All > >> > > > > >>>> >>>>>>> TVR > >> > > > > >>>> >>>>>>>>>>>> rewrite > >> > > > > >>>> >>>>>>>>>>>>> rules are logical rules. All existing Calcite > >> > rules > >> > > > > still > >> > > > > >>>> work > >> > > > > >>>> >>> in > >> > > > > >>>> >>>>>>>> the > >> > > > > >>>> >>>>>>>>>> new > >> > > > > >>>> >>>>>>>>>>>>> volcano system without modification. > >> > > > > >>>> >>>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>>> All changes in this feature will consist of > >> four > >> > > > parts: > >> > > > > >>>> >>>>>>>>>>>>> 1. Memo extension with TvrMetaSet > >> > > > > >>>> >>>>>>>>>>>>> 2. Rule engine upgrade, capable of matching > >> > TvrMetaSet > >> > > > > and > >> > > > > >>>> >>>>>>> RelNodes, > >> > > > > >>>> >>>>>>>>>> as > >> > > > > >>>> >>>>>>>>>>>>> well as links in between the nodes. > >> > > > > >>>> >>>>>>>>>>>>> 3. A basic set of TvrRules, written using the > >> > upgraded > >> > > > > >>>> rule > >> > > > > >>>> >>>>>>> engine > >> > > > > >>>> >>>>>>>>>> API. > >> > > > > >>>> >>>>>>>>>>>>> 4. Multi-query optimization, used to find the > >> best > >> > > > > >>>> incremental > >> > > > > >>>> >>>>>>> plan > >> > > > > >>>> >>>>>>>>>>>>> involving multiple time points. > >> > > > > >>>> >>>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>>> Note that this feature is an extension in > >> nature > >> > and > >> > > > > thus > >> > > > > >>>> when > >> > > > > >>>> >>>>>>>>>> disabled, > >> > > > > >>>> >>>>>>>>>>>>> does not change any existing Calcite > behavior. > >> > > > > >>>> >>>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>>> Other than scenarios in the paper, we also > >> applied > >> > > > this > >> > > > > >>>> >>>>>>>>>> Calcite-extended > >> > > > > >>>> >>>>>>>>>>>>> incremental query optimizer to a type of > >> periodic > >> > > > query > >> > > > > >>>> called > >> > > > > >>>> >>>>>>> the > >> > > > > >>>> >>>>>>>>>>>> ‘‘range > >> > > > > >>>> >>>>>>>>>>>>> query’’ in Alibaba’s data warehouse. It > >> achieved > >> > cost > >> > > > > >>>> savings > >> > > > > >>>> >>> of > >> > > > > >>>> >>>>>>> 80% > >> > > > > >>>> >>>>>>>>>> on > >> > > > > >>>> >>>>>>>>>>>>> total CPU and memory consumption, and 60% on > >> > > > end-to-end > >> > > > > >>>> >>> execution > >> > > > > >>>> >>>>>>>>>> time. > >> > > > > >>>> >>>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>>> All comments and suggestions are welcome. > >> Thanks > >> > and > >> > > > > happy > >> > > > > >>>> >>>>>>> holidays! > >> > > > > >>>> >>>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>>> Best, > >> > > > > >>>> >>>>>>>>>>>>> Botong > >> > > > > >>>> >>>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>>>> > >> > > > > >>>> >>>>>>>>>> > >> > > > > >>>> >>>>>>>>>> > >> > > > > >>>> >>>>>>>> > >> > > > > >>>> >>>>>>> > >> > > > > >>>> >>>>>>> > >> > > > > >>>> >>>>>>> -- > >> > > > > >>>> >>>>>>> ~~~~~~~~~~~~~~~ > >> > > > > >>>> >>>>>>> no mistakes > >> > > > > >>>> >>>>>>> ~~~~~~~~~~~~~~~~~~ > >> > > > > >>>> >>>>>>> > >> > > > > >>>> >>>>>> > >> > > > > >>>> >>> > >> > > > > >>>> >> > >> > > > > >>>> > >> > > > > >>>> > >> > > > > > >> > > > > >> > > > > >> > > > -- > >> > > > Viliam Durina > >> > > > Jet Developer > >> > > > hazelcast® > >> > > > > >> > > > <https://www.hazelcast.com> 2 W 5th Ave, Ste 300 | San Mateo, > CA > >> > 94402 | > >> > > > USA > >> > > > +1 (650) 521-5453 <(650)%20521-5453> | hazelcast.com < > https://www.hazelcast.com> > >> > > > > >> > > > -- > >> > > > This message contains confidential information and is intended > only > >> for > >> > > > the > >> > > > individuals named. If you are not the named addressee you should > not > >> > > > disseminate, distribute or copy this e-mail. Please notify the > >> sender > >> > > > immediately by e-mail if you have received this e-mail by mistake > >> and > >> > > > delete this e-mail from your system. E-mail transmission cannot be > >> > > > guaranteed to be secure or error-free as information could be > >> > intercepted, > >> > > > corrupted, lost, destroyed, arrive late or incomplete, or contain > >> > viruses. > >> > > > The sender therefore does not accept liability for any errors or > >> > omissions > >> > > > in the contents of this message, which arise as a result of e-mail > >> > > > transmission. If verification is required, please request a > >> hard-copy > >> > > > version. -Hazelcast > >> > > > > >> > > >> > > >
