多项选择题
A.A primary key must exist for creation of a clustered index
B.A clustered index allows fulltext searching within InnoDB
C.The first unique index is always used as a clustered index and not a primary key
D.A clustered index provides direct access to a page containing row data
E.If no indexes exist, a hidden clustered index is generated based on row IDs
F.A primary key is used as a clustered index
G.A clustered index is a grouping of indexes from different tables into a global index for faster searching
多项选择题 Which two events will cause a slave server to create a new relay log file?（）
单项选择题 You want to start monitoring statistics on the distribution of storage engines that are being used and the average sizes of tables in the various databases. Some details are as follows: The Mysql instance has 400 databases. Each database on an average consists of 25-50 tables. You use the query: SELECT TABLE_SCHEMA, ENGINE, COUNT (*), SUM(data_length) total_size FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE= BASE TABLE GROUP BY TABLE_SCHEMA, ENGINE ; Why is this query slow to execute?（）
多项选择题 Which two are correct steps in taking a binary backup of MyISAM tables?（）