I believe that subscriber lists are only available to mailing list administrators.
I know that Pranav is not subscribed because, as a moderator, I receive an email each time he posts. You can find out about (and manage) your own subscription status by emailing dev-h...@calcite.apache.org. Julian > On Aug 5, 2022, at 9:06 PM, Benchao Li <libenc...@apache.org> wrote: > > Julian, > > Could you teach me how to know whether someone has subscribed to the ML or > not quickly? > I searched this question and found[1], but this way is not very handy. > > [1] > https://wiki.openoffice.org/wiki/Documentation/FAQ/General/How_to_know_if_a_user_is_subscribed_to_a_mailing_list > > Benchao Li <libenc...@apache.org> 于2022年8月6日周六 11:56写道： > >> Pranav, >> >> You can reference Calcite adaptors implementation, such as JDBC >> Adaptor[1], MongoDB Adaptor[2]. >> Their implementation allows pushing down operations (RelNode) to the >> adapter as much as possible, and the left RelNodes will be implemented >> using Enumerable Convention. >> >> We have a Converter[3] concept which makes this possible. The converter >> node allows multiple Conventions in a single query. This also answers your >> second question. >> There is a talk[4] about this, it's very helpful for understanding this >> concept. >> >> [1] >> https://github.com/apache/calcite/blob/main/core/src/main/java/org/apache/calcite/adapter/jdbc/JdbcToEnumerableConverter.java >> [2] >> https://github.com/apache/calcite/blob/main/mongodb/src/main/java/org/apache/calcite/adapter/mongodb/MongoToEnumerableConverter.java >> [3] >> https://github.com/apache/calcite/blob/main/core/src/main/java/org/apache/calcite/rel/convert/Converter.java >> [4] >> https://calcite.apache.org/community/#fast-federated-sql-with-apache-calcite >> >> Julian Hyde <jhyde.apa...@gmail.com> 于2022年8月6日周六 02:06写道： >> >>> Pranav, >>> >>> Please subscribe to this list. You have asked several questions, received >>> replies, not acknowledged those replies, and asked further questions. Also, >>> since you are not subscribed, each email you post has to go through manual >>> moderation. >>> >>> Julian >>> >>>> On Aug 5, 2022, at 9:38 AM, Pranav Deshpande < >>> deshpande.v.pra...@gmail.com> wrote: >>>> >>>> Dear Apache Calcite Team, >>>> I have 2 questions. >>>> >>>> --------------------------------- >>>> 1. >>>> >>>> There are plenty of examples on how to push down projects and filters >>> into >>>> the leaf nodes (tablescans). >>>> >>>> However, I could not find any examples to push down joins to TableScans >>> (or >>>> joins+filters+projects etc.) [this is helpful for data federation I >>> think]. >>>> >>>> On the mailing list, many folks are suggesting that I use Drill. >>> However, >>>> the purpose of my exercise is to gain knowledge about DBMS and Query >>>> processing etc. >>>> >>>> I tried debugging open source engines that use Calcite (Drill, Druid, >>> Trino >>>> etc.) but was completely lost. >>>> >>>> Any examples/pointers/guidance around the same would be appreciated. >>>> Example, pushing down a join with a filter to a DBMS(consider jdbc >>>> msql etc.) >>>> >>>> ------------------------------------- >>>> 2. >>>> >>>> The 2nd question I have is regarding conventions and different DBMS. The >>>> cluster has a method to replace the trait convention(Bindable,JDBC >>> etc.), >>>> and then we optimize and get the physical plan. >>>> >>>> But imagine I have both the MYSQL JDBC convnction and a cassandra >>>> convention and some user is trying to query both tables. >>>> >>>> Something like "SELECT users.username, specialdata.country from >>>> cassandraDB.user join mysqlDB.specialdata ON users.id >>> =specialdata.userid" >>>> >>>> Now, how will calcite do the optimization here? The planner is not >>>> accepting 2 different conventions. >>>> >>>> Thanks & Regards, >>>> Pranav >>> >>> >> >> -- >> >> Best, >> Benchao Li >> > > > -- > > Best, > Benchao Li
