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 are 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.
For variables, “@” counts as 1 byte, and names can be up to 254 bytes long.
