Have a view query connection Zhang Dabiao but itself query speed not slow
There is a such
Select
.
From A, B,...
Where a. id=B.i d
.
And A.u pdatetime & gt; Sysdate - 30;

Now view need to join table data including citigroup C ame=B.n ame
The view into

Select
.
From A, B, C...
Where a. id=B.i d
And B.n ame=C.n ame
.
And A.u pdatetime & gt; Sysdate - 30;

Then the query time present nearly one hundred times of growth,

A table is very big, but A.u pdatetime is indexed, 30 days because of the time limit, the original view query speed in fact as long as A few seconds;
B and C table data table is only more than one hundred, I was puzzled why connection after C table query speed become so slow?