oracle - ORA-00054: resource busy and acquire with NOWAIT specified or timeout expired

Question

Why am I getting this database error when I update a table?

ERROR at line 1: ORA-00054: resource busy and acquire with NOWAIT specified or timeout expired

Answer 1

Your table is already locked by some query. For example, you may have executed "select for update" and have not yet committed/rollbacked and fired another select query. Do a commit/rollback before executing your query.