垄断的基本类型有哪些？
What are three methods to reduce Mysql server exposure to remote connections?（） Setting — skip-networking when remote connections are not required。 Using the sql_mode=STRICT_SECURE after connections are established for encrypted communications。 Setting specific GRANT privilege to limit remote authentication。 Setting – mysql_secure_configuration to enable paranoid mode。 Using SSL when transporting data over remote network。
You have joined a new organization as a Database Administrator. The Security Administrator in your organization has kept human errors， such as erroneously dropping users， tables， and important data， to a minimum by carefully granting only the necessary privileges to each user. As a result of several ongoing transactions within your database， you discover that the flashback logs are rapidly increasing in the flash recovery area. To avoid out-of-space errors， you decide to delete the flashback logs from the flash recovery area. How can you delete the flashback logs from the database if your database is up and running？（） Shut down the database using the SHUTDOWN command. Mount the database using the STARTUP MOUNT EXCLUSIVE command and disable Flashback Database using the ALTER DATABASE FLASHBACK OFF statement.。 Change the parameter setting in the SPFILE for the DB_RECOVERY_FILE_DEST parameter using the ALTER SYSTEM SET DB_RECOVERY_FILE_DEST=’’ SCOPE=BOTH statement while the database is up and running.。 Shut down the database using the SHUTDOWN command. Mount the database using the STARTUP MOUNT EXCLUSIVE command. Change the parameter setting in the SPFILE for the DB_RECOVERY_FILE_DEST parameter using the ALTER SYSTEM SET DB_RECOVERY_FILE_DEST=’’ SCOPE=BOTH statement. Disable Flashback Database using the ALTER DATABASE FLASHBACK OFF statement.。 Change the parameter setting in the SPFILE for the DB_RECOVERY_FILE_DEST parameter using the ALTER SYSTEM SET DB_RECOVERY_FILE_DEST=’’ SCOPE=BOTH statement. Shut down the database using the SHUTDOWN command. Mount the database using the STARTUP MOUNT EXCLUSIVE command and disable Flashback Database using the ALTER DATABASE FLASHBACK OFF statement.。
《水电站大坝安全管理规定》有关大坝工程建设的主要规定中对于坝高（）m以上的高坝或者监测系统复杂的中坝、低坝，项目法人应当按照国家有关规定，组织有关单位对水电站大坝监测系统进行专项设计、专项审查。 40。 60。 70。 80。
Which statements are true regarding system-partitioned tables？（） Only a single partitioning key column can be specified.。 All DML statements must use partition-extended syntax.。 The same physical attributes must be specified for each partition.。 Unique local indexes cannot be created on a system-partitioned table.。 Traditional partition pruning and partitionwise joins are not supported on these tables.。
三相异步电动机的转差率是转差与（）的比值。
