Here’s a nice table of reserved words in PostgreSQL:
http://www.postgresql.org/docs/current/static/sql-keywords-appendix.html
It is probably best to simply avoid using those words as table- or column-names.
An alternative, however, is to enclose the identifier in double-quotes, e.g.:
CREATE TABLE IF NOT EXISTS apiss (
skey TEXT,
time INTEGER,
"user" TEXT,
ip TEXT);
Additionally, Postgres reserves system column names for internal use in every table:
“Every table has several system columns that are implicitly defined by the system. Therefore, these names cannot be used as names of user-defined columns.”
https://www.postgresql.org/docs/current/ddl-system-columns.html