DbString, IsFixedLength and IsAnsi for varchar

Question

I am new to Dapper, want to know why below is suggested, when my code runs without it?

Ansi Strings and varchar

Dapper supports varchar params, if

Answer 1

The purpose of the example is that it is describing a scenario where the data type is char(10). If we just used "abcde", Dapper might think that nvarchar(5) was appropriate. This would be very inefficient in some cases - especially in a where clause, since the RDBMS can decide that it can't use the index, and instead needs to table scan doing a string conversion for every row in the table from char(10) to the nvarchar version. It is for this reason that DbString exists - to help you control exactly how Dapper configures the parameter for text data.

I think this answers your 1 and 2.

3: are you using ANSI (non-unicode text) or fixed-width text? Note that the ANSI default can also be set globally if you always avoid unicode

4: yes

5: yes

4+5 combined: if you're using nvarchar: just use string