Add SQL Support for MERGE INTO In Presto

[agrawalreetika]

Currently, the Presto engine doesn't have SQL syntax support for MERGE INTO.

Once MERGE INTO is added then we can add MERGE INTO query support for Presto Iceberg Connector -
https://iceberg.apache.org/docs/latest/spark-writes/#merge-into

[bearownage]

Can I take a shot at implementing this?

[tdcmeehan]

@bearownage yes, please go for it.

[carpente]

Hi @bearownage,

I'm considering adding support for MERGE INTO in the Presto Iceberg Connector. I noticed that you are working on adding SQL syntax support for MERGE INTO in Presto. How is the development progressing? Will you also add support for MERGE INTO in the Presto Iceberg Connector, or can I work on that part?

[tdcmeehan]

@acarpente-denodo to my knowledge no one is working on it. Please feel free to get started on the syntax changes as well, and let me know if you need any help.

[bearownage]

Hello @acarpente-denodo

I added some syntax support here: master...bearownage:presto:adam3 amongst other things but I think most of the code outside of just parsing the command is wrong and I probably will have to rewrite most of it. Feel free to take a look and take what you need. I was not planning on adding support for the Presto Iceberg Connector when I took on this task.

[carpente]

Thank you, @tdcmeehan and @bearownage, for letting me know the current state of this feature. My plan is to add support for UPDATE and MERGE to the Presto Iceberg connector.