Add support for PGroonga.EntityFrameworkCore EF.Functions

[kinosang]

Unfortunately, it seems a filter is still required to run DbFunctions on ef core 3.0.

[roji]

@kinosang you're right that evaluatable filter is still needed in 3.0 - I've reopened dotnet/efcore#13454 to discuss.

However, just to be sure, this should only be needed if we have function calls which don't reference any columns, and which should still be evaluated at the server. Good examples are DateTime.Now, random number/guid generation and the like. Can you confirm you have cases like this with PGroonga (and out of curiosity, which one(s))?

[kinosang]

@roji PGroonga has two types of functions, they are:

1.functions without parameter such as PgroongaIsWritable, PgroongaScore, PgroongaWalApply, and PgroongaWalTruncate,
2. others accept constant or variable (maybe a column, but majorly not).

All the functions should be translated and evaluated at the server.

[roji]

1.functions without parameter such as PgroongaIsWritable, PgroongaScore, PgroongaWalApply, and PgroongaWalTruncate,

These are global checks on the database, right? i.e. whether the database is writable, or to make pgroonga do something at the global level?

[roji]

Merged and backported for 3.0.1.

[kinosang]

1.functions without parameter such as PgroongaIsWritable, PgroongaScore, PgroongaWalApply, and PgroongaWalTruncate,

These are global checks on the database, right? i.e. whether the database is writable, or to make pgroonga do something at the global level?

Yes, the PgroongaIsWritable, PgroongaWalApply, and PgroongaWalTruncate are.

But no, the PgroongaScore isn't.

The pgroonga_score accepts two arguments, they are tableoid and ctid (in raw SQL, fragment, not a constant, without any quotation), it only works in a SELECT query with pgroonga matching or searching.

https://github.com/JoyMoe/PGroonga.EntityFrameworkCore/blob/b9d3702a1a01cac8b1fe0e54598112c92a84fc6c/src/PGroonga.EntityFrameworkCore/Query/ExpressionTranslators/Internal/PGroongaMethodCallTranslatorPlugin.cs#L78-L83

[roji]

Thanks for the added details @kinosang!

I need to put together a page with links to interesting/relevant external plugins, where yours could be listed (npgsql/doc#13).

[roji]

I'll also try to publish 2.2.6 soon so that the PGroonga support there is unblocked as well.