what's the step to reorganize a table by using
CTAS(create table as select)?


let's say we have table parent and child.
we can
create table parent_new as select * from parent.
rename parent to parent_old;
rename parent_new to parent.
but do we need to lock table parent during the CTAS?
if not, what happen if somebody insert some new record to
parent while we copy it over to parent_new?
some record may lost.

give me a hint