When you create a table, you name its columns and supply a datatype for each column. You can also specify whether a particular column can hold null values or specify integrity constraints for columns in the table. There can be as many as 2,000,000,000 tables per database.
The limits for the length of object names or identifiers: 255 bytes for regular identifiers, and 253 bytes for delimited identifiers. This limit applies to most user-defined identifiers including table name, column name, index name and so on. Due to the expanded limits, some system tables (catalogs) and built-in functions have been expanded.
For variables, “@” count as 1 byte, and the allowed name for it is 254 bytes long.
