Example: a trigger expression (in internal representation) is already close to maximum length (255 bytes in version 2.0 or 2048 bytes in ZBXNEXT-1186). A database conversion to Distributed Monitoring replaces short IDs with long IDs. The expression does not fit into maximum length anymore. It gets truncated to acceptable length and conversion is reported as successful. The truncated expression is not equivalent to original - it may stop working as syntactically incorrect or produce wrong result.