The UNIQUE constraint does not permit a null value for the column.
A UNIQUE index gets created for columns with PRIMARY KEY and UNIQUE constraints.
The PRIMARY KEY and FOREIGN KEY constraints create a UNIQUE index.
The NOT NULL constraint ensures that null values are not permitted for the column.
第1题:
A. 1 is the default precedence.
B. A lower number is preferred.
C. A higher number is preferred.
D. 100 is the default precedence.
第2题:
Which two statements are true about L2TP tunnels?() (Choose two.)
第3题:
A. PAT is not supported.
B. PAT is enabled by default.
C. It supports the address-persistent configuration option.
D. It supports the junos-global configuration option.
第4题:
Which two statements about VPLS are true? ()
第5题:
Which two statements about the Cisco Nexus 1000V VSM are true?()
第6题:
Which two statements about VACLs on Cisco Nexus 7000 Series Switches are true? ()
第7题:
Which two statements are true about traffic shaping?()
第8题:
A. AH provides data integrity.
B. AH is identified by IP protocol 50.
C. AH is identified by IP protocol 51.
D. AH cannot work in conjunction with ESP
第9题:
Which two statements about OSPF IPv6 routing are true?()
第10题:
Which two statements are true about pool-based source NAT? ()(Choose two.)