Hi i am new,

I have a problem in understanding the query decomposition in D-DB. 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 < ...

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 ?


Thanks in advance