`pgvector` support

[holmofy]

https://github.com/pgvector/pgvector-java

pgvector for nearest neighbor search of high-dimensional vectors.

[vladmihalcea]

@holmofy Looking forward to your Pull Request that adds support for this.

[holmofy]

I took a look at the code of this repository today. In the next few days, I will try to implement this feature.

Because I am not particularly clear about the underlying implementation of hibernate. So I have to look at some of the code of hibernate first to verify some of my ideas.

After that, I will submit a pull request, and please correct me if there are any problems.

In addition, I think the pgvector type of registration may not be suitable for implementation in hibernate.

PGvector.addVectorType(conn);

This needs to be registered when creating a connection. It may not be appropriate to implement this in this library? Looking forward to your reply.

[vladmihalcea]

The Hibernate Type cannot interact with the DB connection directly. You will see in the existing Types how you need to implement this one.

Note that you need to do that for all modules prior to sending the Pull Request.