Database System Concepts
7th Edition
ISBN: 9780078022159
Author: Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher: McGraw-Hill Education
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A
supplies. Price is a relation over products
1…30, which models the association between prices and
stock items. In_stock is a relation over products
N, which models the association between stock items
and the current number in stock of product. Supplies is a relation over suppliers
products which
models the relation between a supplier and the product that is delivered by that supplier. If the current
value of these relations are following:
price = {(nut, 5), (bolt, 13), (screw, 3), (board, 25), (fastener, 23)},
in_stock = {(nut, 700), (bolt, 2200), (screw, 55), (board, 0), (fastener, 600)},
supplies = {(Thomas, nut), (Thomas, bolt), (Wilks, bolt), (Wilks, screw), (Wilks, board), (Wilks,
fastener), (Rogers, board), (Rogers, fastener)},
then what is the value of the following expressions?
i. {nut, bolt} price
ii. dom(price 1…15).
iii. rng(price 1…10).
iv. dom(supplies; (in_stock {0})).
v. price
{(hanger,
5
)
, (screw,
7
)
}
vi. dom(supplies;(price
5
…
2
5)).
vii. supplies |{ | Rogers, Wilson} )(
.
viii. ((supplies; price)
1
…
1
5
)
| | Robinson, Rogers )(
.
ix.
{Thomas
} supplies.
x. (in_stock {0}
)
( | |nut, bolt
) .
![Question 1:
[Marks: =20]
A database of application of wholesaler can be modelled by means of the relations price, in_stock and
supplies. Price is a relation over products ×1...30, which models the association between prices and
stock items. In_stock is a relation over products ×N, which models the association between stock items
and the current number in stock of product. Supplies is a relation over suppliers xproducts which
models the relation between a supplier and the product that is delivered by that supplier. If the current
value of these relations are following:
price = {(nut, 5), (bolt, 13), (screw, 3), (board, 25), (fastener, 23)},
in_stock = {(nut, 700), (bolt, 2200), (screw, 55), (board, 0), (fastener, 600)},
supplies = {(Thomas, nut), (Thomas, bolt), (Wilks, bolt), (Wilks, screw), (Wilks, board), (Wilks,
fastener), (Rogers, board), (Rogers, fastener)},
then what is the value of the following expressions?
{nut, bolt} 4 price
ii. dom(price > 1...15).
iii. ng(price > 1...10).
i.
iv. dom(supplies; (in_stock > {0})).
price e {(hanger,5), (screw, 7)}
vi. dom(supplies:(price> 5...25)).
vii. supplies (| {Rogers, Wilson} |).
V.
viii.
((supplies; price) > 1..15) ({Robinson, Rogers} |).
ix.
{Thomas} < supplies.
(in_stock> {0}) ({nut, bolt} |) .
х.](https://content.bartleby.com/qna-images/question/cc191746-8a0e-40d3-8810-7ee0644a2947/7e855e65-710c-4b35-a7df-691d170fba19/whyc7qc_processed.png)
Transcribed Image Text:Question 1:
[Marks: =20]
A database of application of wholesaler can be modelled by means of the relations price, in_stock and
supplies. Price is a relation over products ×1...30, which models the association between prices and
stock items. In_stock is a relation over products ×N, which models the association between stock items
and the current number in stock of product. Supplies is a relation over suppliers xproducts which
models the relation between a supplier and the product that is delivered by that supplier. If the current
value of these relations are following:
price = {(nut, 5), (bolt, 13), (screw, 3), (board, 25), (fastener, 23)},
in_stock = {(nut, 700), (bolt, 2200), (screw, 55), (board, 0), (fastener, 600)},
supplies = {(Thomas, nut), (Thomas, bolt), (Wilks, bolt), (Wilks, screw), (Wilks, board), (Wilks,
fastener), (Rogers, board), (Rogers, fastener)},
then what is the value of the following expressions?
{nut, bolt} 4 price
ii. dom(price > 1...15).
iii. ng(price > 1...10).
i.
iv. dom(supplies; (in_stock > {0})).
price e {(hanger,5), (screw, 7)}
vi. dom(supplies:(price> 5...25)).
vii. supplies (| {Rogers, Wilson} |).
V.
viii.
((supplies; price) > 1..15) ({Robinson, Rogers} |).
ix.
{Thomas} < supplies.
(in_stock> {0}) ({nut, bolt} |) .
х.
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