I was surprised to find that psql -f file.sql with a file such as this
select 1; select 2
executes both commands even though the second one is not terminated.
I realize that this is inconsistently handled throughout the system, for example libpq APIs don't care about the missing semicolon, but interactive psql does.
Furthermore, if the query string looks like ";;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;" the backend will return EmptyQueryResponse. But according to http://www.postgresql.org/docs/9.2/static/protocol-flow.html EmptyQueryResponse means "An empty query string was recognized." But this is debatable what is meant by "empty query string" -- when strlen(query_string) == 0 or when the query_string does not contains any SQL command?
But what bothered me about this is that if a file gets truncated by accident, there could be an unqualified DELETE or something similar at the end.