There is a thirty character limit on names of tables, columns, and foreign key references in Oracle.

What is more, foreign key references by convention have names which include the names of the two tables they associate together plus a few other characters. This means that table names really need to be kept terse. If a column is indexed, then the number of the index, such as a two for the second index, will be, by convention, bolted onto the column name like so: mycolumn_2 ...so here too there is, to some extent, reason to be wary of pushing how long a column name may be up to the thirty character cap.