Sql-server – Can you separate schemas and objects with spaces and line feeds in T-SQL

There may be an impact on the performance of the query optimizer, albeit a small one, depending on your coding style. If you reference a table without a schema, the optimiser has to try to identify the table first by checking tables within the users default schema (if there is one), then using dbo., and then everything else. If you explicitly reference the tables as schema.table, which is probably good practice anyway, then even this minor overhead will be avoided.

A tablespace creates a layer of abstraction between physical and logical data

By using tablespaces, an administrator can control the disk layout of an installation. A common use of tablespaces is to optimize performance. For example, a heavily used index can be placed on a fast disk. On the other hand, a database table which contains archived data that is rarely accessed could be stored on a less expensive but slower disk.