JOIN pushdown availability

[RodolfoFerreira-FitCard]

Version of tds_fdw

2.0.3

Version of PostgreSQL

PostgreSQL 15.3 on aarch64-unknown-linux-gnu, compiled by aarch64-unknown-linux-gnu-gcc (GCC) 9.5.0, 64-bit

Hello everyone!

Currently, I have a scenario where the company is migrating from a MSSQL database to a PostgreSQL one. The thing is that the applications are very coupled in database level, and not every app will be migrated yet. This causes a need for some refactoring involving another teams providing APIs so I can use it inside my project. For now, they are working on it, but it will take a bit longer.

So, we are using tds_fdw to keep access to data in MSSQL. However, plenty of our queries join data from both sides, or even joins data from two tables on MSSQL, but executing in a postgreSQL server.

As far as i know, tds_fdw do not pushdown join filters, causing all data from tables to be fetch and joined locally. In some queries this is causing millions of rows being fetched because the joins are not going to the remote, affecting the application's performance.

With this in mind, I would like to know if there are plans to implement join pushdowns, or am I missing some configuration that I couldn't found for any reason?

I appreciate any help on the matter, and apologize in advance if I did something wrong with the description of the issue.

Thank you very much!