In MYSQL, what is the following description about the HASH index?
A. If a MYISAM table is changed to a MEMORY table with a HASH index, it will not affect the query execution efficiency.
B. Only for equality comparison using = or <=> operator
C. The optimizer cannot use HASH indexes to speed up Order By operations
D. Use only whole keywords to search one line
Answer:B
In MYSQL, what is the following description about the HASH index?
A. If a MYISAM table is changed to a MEMORY table with a HASH index, it will not affect the query execution efficiency. B. Only for equality comparison using = or <=> operator C. The optimizer cannot use HASH indexes to speed up Order By operations D. Use only whole keywords to search one line