Add convention plugin to configure vector properties as not auto-loaded

[roji]

When loading entities, EF currently always loads all their properties; in the case of vector properties, this isn't needed in the vast majority of cases (as embeddings are used for similarity search in the database but rarely need to be fetched back), and the non-trivial size of embeddings make this a performance problem. For EF 11, we are mitigating this in dotnet/efcore#37277.

We should apply this for pgvector as well. This means introducing an IConventionSetPlugin that would add a convention to mark pgvector properties as non-auto-loaded, similar to the SQL Server convention. I'm happy to submit a PR for this.

@ankane in general regarding versioning... I see that the latest version of Pgvector.EntityFrameworkCore depends on EF 9.0. With 10.0 out and 9.0 going out of support this year, we should probably (a) release a version that targets EF 10.0, and then (b) prepare (and possibly release) another prelease version (incrementing the major or minor version) to target EF 11 (which should be out in November). We should also probably take a look at the lower-level pgvector/Npgsql versions as well.

Let me know what you think, am happy to work on all this as needed.

[ankane]

Hi @roji, happy to review a PR for this.

For versioning, the latest version should work with both EF 9 and 10 (the version constraint is >= 9.0.1), but let me know if there are benefits to doing things differently.

[roji]

Great.

For versioning, the latest version should work with both EF 9 and 10 (the version constraint is >= 9.0.1), but let me know if there are benefits to doing things differently.

It's definitely fine for now (as long as the extension works well against both, which I think it does), but in November 9.0 goes out of support, and at that point the EF 9.0.x brought in by your package will start generating warnings etc. So it's a good idea to publish a version until then that targets 10.0.x as its minimum. The same is true of the lower-level non-EF package (since Npgsql itself has the same lifecycle).

And since 11.0 is bringing the new "don't load by default" improvement, we'll need to publish another version at the same time that targets 11.0.0 as its minimum.

I'm very happy to do the work here, but just let me know this all makes sense to you, and how you want to version your own packages in light of all of this. You may want to consider simply aligning with the .NET/EF/Npgsql versions, i.e. publish https://www.nuget.org/packages/Pgvector.EntityFrameworkCore 10.0.0 and 11.0.0 which depend on the corresponding Npgsql and EF versions.