The biggest misconception with solar covers or rings is that they are meant to heat the pool. While these products may raise the pool temperature, they do so by reducing heat loss (mainly at night). Solar blankets should not be left on a pool during daylight hours, and at the very least, they should be removed for a 4-8 hours during the day for the pool to breathe.
ALTER DATABASE ... SET autocommit = 1 causes an implicit commit if the value was 0. All these statements cause an implicit commit before execution. This means that, even if the statement fails with an error, the transaction is committed. Some of them, like CREATE TABLE ... SELECT, also cause a commit immediatly after execution.
A dummy argument of a statement function must not be redefined or become undefined through a function subprogram reference in the expression of a statement function. The symbolic name of a statement function cannot be an actual argument and must not appear in an EXTERNAL statement.