单项选择题
Consider the following:
Which statement best describes the meaning of the value for the key_len column?（）
A.It shows the total size of the index row
B.It shows how many columns in the index are examined
C.It shows the number of characters indexed in the key
D.It shows how many bytes will be used from each index row
相关考题
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单项选择题
An employee cannot access the company database. You check the connection variables: What is a valid explanation for why one of the users is unable to connect to the database?（）
A.Bob has max_user_connections set to zero, which blocks all his connections
B.Joe has exceeded the max_user_connections global limit
C.All users are blocked because max_user_connections is accumulated over the host account information
D.Kay is already connected elsewhere and attempting to log in again
E.Connect_timeout is too small to allow a connection to occur -
单项选择题
Your developers have created table to store some of their programs data. After examining the slow Query Log, you see that they are using the LIKE operator and SUBSTER () functions against a VARCHAR (10000) column quite often. An example of the start of one row of data: GREEN01020495888331993-12-10/2… What should you do to improve the overall performance?（）
A.Convert the column to TEXT and add a fulltext index to the table
B.Create multiple prefix indexes of differing lengths
C.Convert their column to BINARY
D.Redesign the table so that the most commonly searched for string patterns are in their own columns -
多项选择题
Which three are properties of the MyISAM storage engine?（）
A.Transaction support
B.FULLTEXT indexing for text matching
C.Table and page level locking support
D.Foreign key support
E.Geospatial indexing
F.HASH index support
G.Table level locking only
