Unicode conversion default behaviour. Not changeable when using string interpolated queries.

It is not possible to change the default string conversion (nvarchar2) in an interpolated string.

e.g.

 db.Model.FromSqlInterpolated("select ... from ... where key in (... field = {val} ...)")

What I already considered:

• https://docs.oracle.com/en/database/oracle/oracle-database/21/odpnt/EFCorePerformanceConsiderations.html#GUID-E12B036C-A8B7-4891-9713-B079AC4815DD

Note that field is not accessible in Model.

It would be really nice to globaly change the behaviour of using varchar2 instead of nvarchar2.
Something like:

builder.Services.AddDbContext<DataContext>(
    options => options.UseOracle(builder.Configuration.GetConnectionString("DB"),
    oraOptionsBuilder => oraOptionsBuilder.UserVarchar2()));

This would also allow to be a little more lazy on the column type definition with HasColumnType.

Start by reproducing the issue with the FromSqlInterpolated example and review the linked Oracle EF Core performance considerations. The requested outcome is a global configuration option like UserVarchar2() that changes interpolated-query string conversion without requiring field access or repeated HasColumnType configuration.