Correlated Sub-queries: Normal CSQ

QUERY:

update orders set ship_charge = 0

where exists (

select "X" from customer c

where c.customer_num = orders.customer_num

and c.state = "MD” )

1) informix.orders: SEQUENTIAL SCAN

Filters: EXISTS <subquery>

Subquery:

---------

Estimated Cost: 1

Estimated # of Rows Returned: 1

1) informix.c: INDEX PATH

Filters: informix.c.state = 'MD'

(1) Index Keys: customer_num

Lower Index Filter:

c.customer_num = orders.customer_num

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