Postgres wire protocol for the cache

[abcpro1]

Many databases implement the Postgres wire protocol for their SQL interface. Postgres wire protocol automatically gives access to JDBC, ODBC, the psql command line client, in addition to all other existing Postgres clients.

If we put a SQL interface on the cache, what SQL features will we support? Currently, in gRPC and REST we have limit, offset and filter.

Postgres wire protocol also supports streaming. Will we also support this?

[chubei]

We just had a call and the conclusion is that implementing the sql engine using datafusion is the way to go.

For datafusion, we just have to see if we can implement the TableProvider trait to use cache as a table.

And then we support whatever sql features that datafusion gives us.

[abcpro1]

Datafusion has no JSON support (no JSON data type and no JSON functions).
@chubei @v3g42

[chubei]

Yes, and we convert json to string when exporting to arrow. Let's skip that then.