Question: Does tds_fdw lock tables?

[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 product I develop looks to a PostgreSQL database, but needs data from a SQL Server database, so, we use tds_fdw to help us with that.

In the company scenario, we have other products that are only in SQL Server that uses that same SQL Server database that I use to query some informations. The thing is that we've seen a massive performance problem happening, and we don't know if it's just a coincidence or if tds_fdw has something to do with it, because it started a little after we deployed the code with tds.

My question is if tds_fdw locks tables while querying the foreign server. That is one of the causes of the performance issue, and in our product we do some 2s long queries in an database that can have concurrent queries from sql server connections from other products. As I see, the behaviour should be the same as if we were querying from SQL Server itself. Is that the case?

I should say that we created the foreign server and imported the full dbo schema as foreign tables.

I appreciate your help in advance!

Thank you!