Reserved words
Informix®
With Informix, it is possible to create database objects with reserved words.
CREATE TABLE table ( char CHAR(10) );
Indeed this is not good practice, but Informix SQL allows this to be backward compatible when introducing a new keyword in the SQL syntax.
Most other database systems do not allow reserved words as database identifiers. If your legacy
code is using SQL reserved words of the target database SQL syntax, an error will be thrown at
CREATE TABLE
execution.
PostgreSQL
SQL object names like table and column names can be SQL reserved words in PostgreSQL.
However, this is not good practice and must be avoided.
Solution
Table or column names which are PostgreSQL reserved words must be renamed.
For a list of reserved PostgreSQL keywords, see https://www.postgresql.org/docs/current/sql-keywords-appendix.html.