Which of the following can be used to ensure that once a row has been inserted in table TABLEX, the column MAINID in that row cannot be updated?（）

单项选择题Given the following requirements:Create a table named TESTTAB, which has an identity column named ACTIVITYNO. Define the identity column to generate the values for the column by default. Start the values at 10 and increment by 10. Make the identity column unique. Which of the following CREATE statements will successfully create this table?（）

A.CREATE TABLE TESTTAB (ACTIVITYNO SMALLINT NOT NULL GENERATED ALWAYS AS IDENTITY (START WITH 10 INCREMENT BY 10), ACTKWD CHAR(6) NOT NULL, ACTDESC VARCHAR(20) NOT NULL, UNIQUE(ACTIVITYNO))
B.CREATE TABLE TESTTAB (ACTIVITYNO SMALLINT NOT NULL GENERATED ALWAYS AS IDENTITY (START WITH 1 INCREMENT BY 10), ACTKWD CHAR(6) NOT NULL, ACTDESC VARCHAR(20) NOT NULL, UNIQUE(ACTNO))
C.CREATE TABLE TESTTAB (ACTIVITYNO SMALLINT NOT NULL GENERATED BY DEFAULT AS IDENTITY (START WITH 10 INCREMENT BY 1), ACTKWD CHAR(6) NOT NULL, ACTDESC VARCHAR(20) NOT NULL, UNIQUE(ACTIVITYNO))
D.CREATE TABLE TESTTAB (ACTIVITYNO SMALLINT NOT NULL GENERATED BY DEFAULT AS IDENTITY (START WITH 10 INCREMENT BY 10), ACTKWD CHAR(6) NOT NULL, ACTDESC VARCHAR(20) NOT NULL, UNIQUE(ACTIVITYNO))

单项选择题The following triggers were defined for table TAB1 in the order shown:CREATE TRIGGER trig_a AFTER UPDATE ON tab1 FOR EACH ROW UPDATE sale_tab SET sale_date = CURRENT DATE; CREATE TRIGGER trig_b AFTER UPDATE ON tab1 FOR EACH STATEMENT UPDATE invoice_tab SET invoice_date = CURRENT DATE; CREATE TRIGGER trig_c AFTER UPDATE ON tab1 FOR EACH ROW UPDATE shipping_tab SET ship_date = CURRENT DATE; CREATE TRIGGER trig_d AFTER UPDATE ON tab1 FOR EACH STATEMENT UPDATE billing_tab SETbilling_date = CURRENT DATE;If an event occurs that causes all of them to activate, which trigger will be activated first?（）

A.TRIG_A
B.TRIG_B
C.TRIG_C
D.TRIG_D

单项选择题Which of the following strings can be inserted into an XML column using XMLPARSE?（）

A."<employee/>"
B."<?xml version='1.0' encoding='UTF-8' ?>"
C."<!DOCTYPE hello SYSTEM 'hello_world.dtd'>"
D."<x xmlns:ibmcert='http://www.ibm.com/certify'>"

单项选择题What is the maximum size that can be specified when creating an XML column in a DB2 table?（）

A.No size is specified
B.The buffer pool size
C.The page size for the table space
D.The extent size for the table space

单项选择题If a unique constraint is defined on column COL1 of table TAB1, what are the characteristics of COL1?（）

A.COL1 will accept NULL values and can be referenced in another table's foreign key specification.
B.COL1 will not accept NULL values and cannot be referenced in another tables foreign key specification.
C.COL1 will not accept NULL values and can be referenced in another tables foreign key specification.
D.COL1 will accept NULL values and cannot be referenced in another tables foreign key specification.