单项选择题
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?（）
单项选择题 If a unique constraint is defined on column COL1 of table TAB1, what are the characteristics of COL1?（）
单项选择题 A DBA has been asked to create a table which will contain a substantial amount of detailed sales information for each calendar month and maintain it to contain only the last 12 months. Which of the following methods will facilitate the online removal of the oldest month’s data?（）