Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations Mike Lewis on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Query decomposition and sub-queries

Status
Not open for further replies.

eustathi

Technical User
May 9, 2007
9
GR
Hello

Can anyone can help me to understand the first question of the exercise 25,21 of Elmasri-Navath 4th edition?

We have a distributed database system:
3 bookstores S1,S2,S3 and the books are distributed in this way
S1: B1 B4
S2: B1 B2
S3: B1 B2 B3 B4

where BOOKS
B1 : 0<price <20
B2 : 20<=price <50
B3 : 50<=price<100
B4 : 100<price < ...

Code:
And we execute the query in the S1
SELECT book_code
FROM BOOKS
WHERE price >15 and price <55

What will be the new sub-queries? It will execute the above select in each store S1,S2,S3 ?
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top