For each of the following SQL statement refer to the above D

For each of the following SQL statement, refer to the above DDBMS scenario and specify the type of operation it is (remote request, remote transaction, distributed transaction, or distributed request).

At site C:

g. BEGIN WORK;

INSERT INTO INVOICE(INV_NUM, CUS_NUM, INV_DATE, INV_TOTAL)

VALUES (\'986434\', \'24352\', ‘22-AUG-2013’, 2.00);

COMMIT WORK;

h. SELECT * FROM INVOICE WHERE INV_TOTAL < 2000;

i. SELECT * FROM PRODUCT WHERE PROD_QOH < 25;

j. BEGIN WORK;

UPDATE CUSTOMER

SET CUS_BALANCE = CUS_BALANCE + 200

WHERE CUS_NUM=\'12934\';

INSERT INTO INVOICE(INV_NUM, CUS_NUM, INV_DATE, INV_TOTAL)

VALUES (\'867541\', \'14678\', ‘15-DEC-2013’, 200);

UPDATE PRODUCT SET PROD_QOH = PROD_QOH – 3

WHERE PROD_CODE = \'1265\';

COMMIT WORK;

k. BEGIN WORK;

INSERT CUSTOMER(CUS_NUM, CUS_NAME, CUS_ADDRESS, CUS_BAL)

VALUES (\'24352\',\'John Brow\', \'1500 Main St\', 0.00);

COMMIT WORK;

TABLES FRAGMENTS CUSTOMER NA PRODUCT PROD A PROD B NA INVOICE INV LINE NIA CUSTOMER LOCATION Site C PROD B

Solution

g) This SQL sequence represents a remote request. cause its directly inserting into invoice table.

h)This SQL sequence represents a remote request.cause its requesting only one from one table.

i)This SQL sequence represents a distributed request. Note that the distributed request is required when a single request must access two sites. The PRODUCT table is composed of two fragments, PRO_A and PROD_B, which are located in sites A and B, respectively.

j)This SQL sequence represents a distributed request.

Note that UPDATE CUSTOMER and the two INSERT statements only require remote request capabilities. However, the entire transaction must access more than one remote site, so we also need distributed transaction capability. The last UPDATE PRODUCT statement accesses two remote sites because the PRODUCT table is divided into two fragments located at two remote sites. Therefore, the transaction as a whole requires distributed request capability.

k) This SQL sequence represents a remote request.ause its directly inserting into invoice table.

Thank You.