wangqi wrote:
> An SQL execution is very slow.
> What can I do to makes it faster。
Without knowing more about the version of PostgreSQL, your PostgreSQL
configuration, your schema (including indexes), and your hardware,
it's hard to give advice.
http://wiki.postgresql.org/wiki/SlowQueryQuestions
A wild guess on the evidence we have is that you might benefit from
an index on MCL.ctid if you don't already have one.
-Kevin