Reserved words

Informix®

With Informix, it is possible to create database objects with reserved words.

For example:
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.