I believe PubSubIO already exposes the publish timestamp if no timestamp attribute is set.
On Thu, May 3, 2018 at 12:52 PM Anton Kedin <ke...@google.com> wrote: > A SQL-specific wrapper+custom transforms for PubsubIO should suffice. We > will probably need to a way to expose a message publish timestamp if we > want to use it as an event timestamp, but that will be consumed by the same > wrapper/transform without adding anything schema or SQL-specific to > PubsubIO itself. > > On Thu, May 3, 2018 at 11:44 AM Reuven Lax <re...@google.com> wrote: > >> Are you planning on integrating this directly into PubSubIO, or add a >> follow-on transform? >> >> On Wed, May 2, 2018 at 10:30 AM Anton Kedin <ke...@google.com> wrote: >> >>> Hi >>> >>> I am working on adding functionality to support querying Pubsub messages >>> directly from Beam SQL. >>> >>> *Goal* >>> Provide Beam users a pure SQL solution to create the pipelines with >>> Pubsub as a data source, without the need to set up the pipelines in >>> Java before applying the query. >>> >>> *High level approach* >>> >>> - >>> - Build on top of PubsubIO; >>> - Pubsub source will be declared using CREATE TABLE DDL statement: >>> - Beam SQL already supports declaring sources like Kafka and Text >>> using CREATE TABLE DDL; >>> - it supports additional configuration using TBLPROPERTIES >>> clause. Currently it takes a text blob, where we can put a JSON >>> configuration; >>> - wrapping PubsubIO into a similar source looks feasible; >>> - The plan is to initially support messages only with JSON payload: >>> - >>> - more payload formats can be added later; >>> - Messages will be fully described in the CREATE TABLE statements: >>> - event timestamps. Source of the timestamp is configurable. It >>> is required by Beam SQL to have an explicit timestamp column for >>> windowing >>> support; >>> - messages attributes map; >>> - JSON payload schema; >>> - Event timestamps will be taken either from publish time or >>> user-specified message attribute (configurable); >>> >>> Thoughts, ideas, comments? >>> >>> More details are in the doc here: >>> https://docs.google.com/document/d/1wIXTxh-nQ3u694XbF0iEZX_7-b3yi4ad0ML2pcAxYfE >>> >>> >>> Thank you, >>> Anton >>> >>
