Better support for uncommon and/or vendor-specific data types

[bluerogue251]

I'm opening this issue to see how much demand there is for support for uncommon and/or vendor-specific data types.

Right now certain data types cause the program to error out. There is a workaround available for this by using the --excludeColumns option to exclude the problematic columns from subsetting, then handle them manually outside of the DBSubsetter program. However, this is not a great user experience, so the fewer users that have to resort to this kind of workaround, the better.

Examples of data types which are known not to be supported at this time are Postgres money, Postgres user-defined enums, and Postgres arrays of user-defined enums. We would likely find even more problematic data types if we tested custom data types in MySQL and SQL Server more thoroughly.

Related Automated Tests:

• https://github.com/bluerogue251/DBSubsetter/blob/master/src/test/scala/e2e/mysqldatatypes/MySqlDataTypesMySqlTest.scala
• https://github.com/bluerogue251/DBSubsetter/blob/master/src/test/scala/e2e/pgdatatypes/PgDataTypesPostgresqlTest.scala

If you would like such a feature please add a 👍 to this issue, and feel free to leave any specific notes about your use case in this thread.