1.Names must be from 1 to 30 bytes long with these exceptions:
◦Names of databases are limited to 8 bytes.
◦Names of database links can be as long as 128 bytes.
If an identifier includes multiple parts separated by periods, then each attribute can be up to 30 bytes long. Each period separator, as well as any surrounding double quotation marks, counts as one byte. For example, suppose you identify a column like this:
The schema name can be 30 bytes, the table name can by 30 bytes, and the column name can be 30 bytes. Each of the quotation marks and periods is a single-byte character, so the total length of the identifier in this example can be up to 98 bytes.