Hi Lin and Jark, Thanks for sharing those details. Can you please consider summarizing your DDL design into a google doc. We can still continue the discussions on Shuyi's proposal. But having a separate google doc will be easy for the DEV to understand/comment/discuss on your proposed DDL implementation.
Regards, Shaoxuan On Wed, Nov 28, 2018 at 7:39 PM Jark Wu <imj...@gmail.com> wrote: > Hi Shuyi, > > Thanks for bringing up this discussion and the awesome work! I have left > some comments in the doc. > > I want to share something more about the watermark definition learned from > Alibaba. > > 1. > > Table should be able to accept multiple watermark definition. > > Because a table may have more than one rowtime field. For example, one > rowtime field is from existing field but missing in some records, > another > is the ingestion timestamp in Kafka but not very accurate. In this case, > user may define two rowtime fields with watermarks in the Table and > choose > one in different situation. > 2. > > Watermark stragety always work with rowtime field together. > > Based on the two points metioned above, I think we should combine the > watermark strategy and rowtime field selection (i.e. which existing field > used to generate watermark) in one clause, so that we can define multiple > watermarks in one Table. > > Here I will share the watermark syntax used in Alibaba (simply modified): > > watermarkDefinition: > WATERMARK [watermarkName] FOR <rowtime_field> AS wm_strategy > > wm_strategy: > BOUNDED WITH OFFSET 'string' timeUnit > | > ASCENDING > > The “WATERMARK” keyword starts a watermark definition. The “FOR” keyword > defines which existing field used to generate watermark, this field should > already exist in the schema (we can use computed-column to derive from > other fields). The “AS” keyword defines watermark strategy, such as BOUNDED > WITH OFFSET (covers almost all the requirements) and ASCENDING. > > When the expected rowtime field does not exist in the schema, we can use > computed-column syntax to derive it from other existing fields using > built-in functions or user defined functions. So the rowtime/watermark > definition doesn’t need to care about “field-change” strategy > (replace/add/from-field). And the proctime field definition can also be > defined using computed-column. Such as pt as PROCTIME() which defines a > proctime field named “pt” in the schema. > > Looking forward to working with you guys! > > Best, > Jark Wu > > > Lin Li <lincoln.8...@gmail.com> 于2018年11月28日周三 下午6:33写道: > > > @Shuyi > > Thanks for the proposal! We have a simple DDL implementation (extends > > Calcite's parser) which been running for almost two years on production > and > > works well. > > I think the most valued things we'd learned is keeping simplicity and > > standard compliance. > > Here's the approximate grammar, FYI > > CREATE TABLE > > > > CREATE TABLE tableName( > > columnDefinition [, columnDefinition]* > > [ computedColumnDefinition [, computedColumnDefinition]* ] > > [ tableConstraint [, tableConstraint]* ] > > [ tableIndex [, tableIndex]* ] > > [ PERIOD FOR SYSTEM_TIME ] > > [ WATERMARK watermarkName FOR rowTimeColumn AS > > withOffset(rowTimeColumn, offset) ] ) [ WITH ( tableOption [ , > > tableOption]* ) ] [ ; ] > > > > columnDefinition ::= > > columnName dataType [ NOT NULL ] > > > > dataType ::= > > { > > [ VARCHAR ] > > | [ BOOLEAN ] > > | [ TINYINT ] > > | [ SMALLINT ] > > | [ INT ] > > | [ BIGINT ] > > | [ FLOAT ] > > | [ DECIMAL ] > > | [ DOUBLE ] > > | [ DATE ] > > | [ TIME ] > > | [ TIMESTAMP ] > > | [ VARBINARY ] > > } > > > > computedColumnDefinition ::= > > columnName AS computedColumnExpression > > > > tableConstraint ::= > > { PRIMARY KEY | UNIQUE } > > (columnName [, columnName]* ) > > > > tableIndex ::= > > [ UNIQUE ] INDEX indexName > > (columnName [, columnName]* ) > > > > rowTimeColumn ::= > > columnName > > > > tableOption ::= > > property=value > > offset ::= > > positive integer (unit: ms) > > > > CREATE VIEW > > > > CREATE VIEW viewName > > [ > > ( columnName [, columnName]* ) > > ] > > AS queryStatement; > > > > CREATE FUNCTION > > > > CREATE FUNCTION functionName > > AS 'className'; > > > > className ::= > > fully qualified name > > > > > > Shuyi Chen <suez1...@gmail.com> 于2018年11月28日周三 上午3:28写道: > > > > > Thanks a lot, Timo and Xuefu. Yes, I think we can finalize the design > doc > > > first and start implementation w/o the unified connector API ready by > > > skipping some featue. > > > > > > Xuefu, I like the idea of making Flink specific properties into generic > > > key-value pairs, so that it will make integration with Hive DDL (or > > others, > > > e.g. Beam DDL) easier. > > > > > > I'll run a final pass over the design doc and finalize the design in > the > > > next few days. And we can start creating tasks and collaborate on the > > > implementation. Thanks a lot for all the comments and inputs. > > > > > > Cheers! > > > Shuyi > > > > > > On Tue, Nov 27, 2018 at 7:02 AM Zhang, Xuefu <xuef...@alibaba-inc.com> > > > wrote: > > > > > > > Yeah! I agree with Timo that DDL can actually proceed w/o being > blocked > > > by > > > > connector API. We can leave the unknown out while defining the basic > > > syntax. > > > > > > > > @Shuyi > > > > > > > > As commented in the doc, I think we can probably stick with simple > > syntax > > > > with general properties, without extending the syntax too much that > it > > > > mimics the descriptor API. > > > > > > > > Part of our effort on Flink-Hive integration is also to make DDL > syntax > > > > compatible with Hive's. The one in the current proposal seems making > > our > > > > effort more challenging. > > > > > > > > We can help and collaborate. At this moment, I think we can finalize > on > > > > the proposal and then we can divide the tasks for better > collaboration. > > > > > > > > Please let me know if there are any questions or suggestions. > > > > > > > > Thanks, > > > > Xuefu > > > > > > > > > > > > > > > > > > > > ------------------------------------------------------------------ > > > > Sender:Timo Walther <twal...@apache.org> > > > > Sent at:2018 Nov 27 (Tue) 16:21 > > > > Recipient:dev <dev@flink.apache.org> > > > > Subject:Re: [DISCUSS] Flink SQL DDL Design > > > > > > > > Thanks for offering your help here, Xuefu. It would be great to move > > > > these efforts forward. I agree that the DDL is somehow releated to > the > > > > unified connector API design but we can also start with the basic > > > > functionality now and evolve the DDL during this release and next > > > releases. > > > > > > > > For example, we could identify the MVP DDL syntax that skips defining > > > > key constraints and maybe even time attributes. This DDL could be > used > > > > for batch usecases, ETL, and materializing SQL queries (no time > > > > operations like windows). > > > > > > > > The unified connector API is high on our priority list for the 1.8 > > > > release. I will try to update the document until mid of next week. > > > > > > > > > > > > Regards, > > > > > > > > Timo > > > > > > > > > > > > Am 27.11.18 um 08:08 schrieb Shuyi Chen: > > > > > Thanks a lot, Xuefu. I was busy for some other stuff for the last 2 > > > > weeks, > > > > > but we are definitely interested in moving this forward. I think > once > > > the > > > > > unified connector API design [1] is done, we can finalize the DDL > > > design > > > > as > > > > > well and start creating concrete subtasks to collaborate on the > > > > > implementation with the community. > > > > > > > > > > Shuyi > > > > > > > > > > [1] > > > > > > > > > > > > > > > https://docs.google.com/document/d/1Yaxp1UJUFW-peGLt8EIidwKIZEWrrA-pznWLuvaH39Y/edit?usp=sharing > > > > > > > > > > On Mon, Nov 26, 2018 at 7:01 PM Zhang, Xuefu < > > xuef...@alibaba-inc.com> > > > > > wrote: > > > > > > > > > >> Hi Shuyi, > > > > >> > > > > >> I'm wondering if you folks still have the bandwidth working on > this. > > > > >> > > > > >> We have some dedicated resource and like to move this forward. We > > can > > > > >> collaborate. > > > > >> > > > > >> Thanks, > > > > >> > > > > >> Xuefu > > > > >> > > > > >> > > > > >> ------------------------------------------------------------------ > > > > >> 发件人:wenlong.lwl<wenlong88....@gmail.com> > > > > >> 日 期:2018年11月05日 11:15:35 > > > > >> 收件人:<dev@flink.apache.org> > > > > >> 主 题:Re: [DISCUSS] Flink SQL DDL Design > > > > >> > > > > >> Hi, Shuyi, thanks for the proposal. > > > > >> > > > > >> I have two concerns about the table ddl: > > > > >> > > > > >> 1. how about remove the source/sink mark from the ddl, because it > is > > > not > > > > >> necessary, the framework determine the table referred is a source > > or a > > > > sink > > > > >> according to the context of the query using the table. it will be > > more > > > > >> convenient for use defining a table which can be both a source and > > > sink, > > > > >> and more convenient for catalog to persistent and manage the meta > > > infos. > > > > >> > > > > >> 2. how about just keeping one pure string map as parameters for > > table, > > > > like > > > > >> create tabe Kafka10SourceTable ( > > > > >> intField INTEGER, > > > > >> stringField VARCHAR(128), > > > > >> longField BIGINT, > > > > >> rowTimeField TIMESTAMP > > > > >> ) with ( > > > > >> connector.type = ’kafka’, > > > > >> connector.property-version = ’1’, > > > > >> connector.version = ’0.10’, > > > > >> connector.properties.topic = ‘test-kafka-topic’, > > > > >> connector.properties.startup-mode = ‘latest-offset’, > > > > >> connector.properties.specific-offset = ‘offset’, > > > > >> format.type = 'json' > > > > >> format.prperties.version=’1’, > > > > >> format.derive-schema = 'true' > > > > >> ); > > > > >> Because: > > > > >> 1. in TableFactory, what user use is a string map properties, > > defining > > > > >> parameters by string-map can be the closest way to mapping how > user > > > use > > > > the > > > > >> parameters. > > > > >> 2. The table descriptor can be extended by user, like what is done > > in > > > > Kafka > > > > >> and Json, it means that the parameter keys in connector or format > > can > > > be > > > > >> different in different implementation, we can not restrict the key > > in > > > a > > > > >> specified set, so we need a map in connector scope and a map in > > > > >> connector.properties scope. why not just give user a single map, > let > > > > them > > > > >> put parameters in a format they like, which is also the simplest > way > > > to > > > > >> implement DDL parser. > > > > >> 3. whether we can define a format clause or not, depends on the > > > > >> implementation of the connector, using different clause in DDL may > > > make > > > > a > > > > >> misunderstanding that we can combine the connectors with arbitrary > > > > formats, > > > > >> which may not work actually. > > > > >> > > > > >> On Sun, 4 Nov 2018 at 18:25, Dominik Wosiński <wos...@gmail.com> > > > wrote: > > > > >> > > > > >>> +1, Thanks for the proposal. > > > > >>> > > > > >>> I guess this is a long-awaited change. This can vastly increase > the > > > > >>> functionalities of the SQL Client as it will be possible to use > > > complex > > > > >>> extensions like for example those provided by Apache Bahir[1]. > > > > >>> > > > > >>> Best Regards, > > > > >>> Dom. > > > > >>> > > > > >>> [1] > > > > >>> https://github.com/apache/bahir-flink > > > > >>> > > > > >>> sob., 3 lis 2018 o 17:17 Rong Rong <walter...@gmail.com> > > napisał(a): > > > > >>> > > > > >>>> +1. Thanks for putting the proposal together Shuyi. > > > > >>>> > > > > >>>> DDL has been brought up in a couple of times previously [1,2]. > > > > >> Utilizing > > > > >>>> DDL will definitely be a great extension to the current Flink > SQL > > to > > > > >>>> systematically support some of the previously brought up > features > > > such > > > > >> as > > > > >>>> [3]. And it will also be beneficial to see the document closely > > > > aligned > > > > >>>> with the previous discussion for unified SQL connector API [4]. > > > > >>>> > > > > >>>> I also left a few comments on the doc. Looking forward to the > > > > alignment > > > > >>>> with the other couple of efforts and contributing to them! > > > > >>>> > > > > >>>> Best, > > > > >>>> Rong > > > > >>>> > > > > >>>> [1] > > > > >>>> > > > > >>>> > > > > >> > > > > > > > > > > http://mail-archives.apache.org/mod_mbox/flink-dev/201805.mbox/%3CCAMZk55ZTJA7MkCK1Qu4gLPu1P9neqCfHZtTcgLfrFjfO4Xv5YQ%40mail.gmail.com%3E > > > > >>>> [2] > > > > >>>> > > > > >>>> > > > > >> > > > > > > > > > > http://mail-archives.apache.org/mod_mbox/flink-dev/201810.mbox/%3CDC070534-0782-4AFD-8A85-8A82B384B8F7%40gmail.com%3E > > > > >>>> [3] https://issues.apache.org/jira/browse/FLINK-8003 > > > > >>>> [4] > > > > >>>> > > > > >>>> > > > > >> > > > > > > > > > > http://mail-archives.apache.org/mod_mbox/flink-dev/201810.mbox/%3c6676cb66-6f31-23e1-eff5-2e9c19f88...@apache.org%3E > > > > >>>> > > > > >>>> On Fri, Nov 2, 2018 at 10:22 AM Bowen Li <bowenl...@gmail.com> > > > wrote: > > > > >>>> > > > > >>>>> Thanks Shuyi! > > > > >>>>> > > > > >>>>> I left some comments there. I think the design of SQL DDL and > > > > >>> Flink-Hive > > > > >>>>> integration/External catalog enhancements will work closely > with > > > each > > > > >>>>> other. Hope we are well aligned on the directions of the two > > > designs, > > > > >>>> and I > > > > >>>>> look forward to working with you guys on both! > > > > >>>>> > > > > >>>>> Bowen > > > > >>>>> > > > > >>>>> > > > > >>>>> On Thu, Nov 1, 2018 at 10:57 PM Shuyi Chen <suez1...@gmail.com > > > > > > >> wrote: > > > > >>>>>> Hi everyone, > > > > >>>>>> > > > > >>>>>> SQL DDL support has been a long-time ask from the community. > > > > >> Current > > > > >>>>> Flink > > > > >>>>>> SQL support only DML (e.g. SELECT and INSERT statements). In > its > > > > >>>> current > > > > >>>>>> form, Flink SQL users still need to define/create table > sources > > > and > > > > >>>> sinks > > > > >>>>>> programmatically in Java/Scala. Also, in SQL Client, without > DDL > > > > >>>> support, > > > > >>>>>> the current implementation does not allow dynamical creation > of > > > > >>> table, > > > > >>>>> type > > > > >>>>>> or functions with SQL, this adds friction for its adoption. > > > > >>>>>> > > > > >>>>>> I drafted a design doc [1] with a few other community members > > that > > > > >>>>> proposes > > > > >>>>>> the design and implementation for adding DDL support in Flink. > > The > > > > >>>>> initial > > > > >>>>>> design considers DDL for table, view, type, library and > > function. > > > > >> It > > > > >>>> will > > > > >>>>>> be great to get feedback on the design from the community, and > > > > >> align > > > > >>>> with > > > > >>>>>> latest effort in unified SQL connector API [2] and Flink Hive > > > > >>>>> integration > > > > >>>>>> [3]. > > > > >>>>>> > > > > >>>>>> Any feedback is highly appreciated. > > > > >>>>>> > > > > >>>>>> Thanks > > > > >>>>>> Shuyi Chen > > > > >>>>>> > > > > >>>>>> [1] > > > > >>>>>> > > > > >>>>>> > > > > >> > > > > > > > > > > https://docs.google.com/document/d/1TTP-GCC8wSsibJaSUyFZ_5NBAHYEB1FVmPpP7RgDGBA/edit?usp=sharing > > > > >>>>>> [2] > > > > >>>>>> > > > > >>>>>> > > > > >> > > > > > > > > > > https://docs.google.com/document/d/1Yaxp1UJUFW-peGLt8EIidwKIZEWrrA-pznWLuvaH39Y/edit?usp=sharing > > > > >>>>>> [3] > > > > >>>>>> > > > > >>>>>> > > > > >> > > > > > > > > > > https://docs.google.com/document/d/1SkppRD_rE3uOKSN-LuZCqn4f7dz0zW5aa6T_hBZq5_o/edit?usp=sharing > > > > >>>>>> -- > > > > >>>>>> "So you have to trust that the dots will somehow connect in > your > > > > >>>> future." > > > > >> > > > > > > > > > > > > -- > > > "So you have to trust that the dots will somehow connect in your > future." > > > > > >