出口中间继电器的起动电压（）。 无特殊要求。 必须不大于50%额定电压。 不得低于50%额定电压。
You have a large amount of historical data in an operating system file. Some analysts in your organization need to query this data. The file is too large to load into your current database. Which is the most effective method to accomplish the task？（） Upgrade the hardware/memory to accommodate the data.。 Load the data into your database by using the PARALLEL clause.。 Give analysts DBA privilege， so that they can query DBA_EXTERNAL_TABLES.。 Use an external table so you can have the metadata available in your database， but leave the data in the operating system files.。
农村土地承包法的基本原则？
You have recovered your Oracle Database 10g by using the control file backup because all copies of the current control file have been lost due to a media failure. You open your database by using the following statement： SQL>ALTER DATABASE OPEN RESETLOGS； Which of the following options is true about using the RESETLOGS option？（） The log sequence is reset to 0.。 All the online redo logs are deleted.。 All the archived redo logs from a previous incarnation become useless.。 The full database backup taken from a previous incarnation can be used in future.。 Only the control file and online redo log files are updated with a new RESETLOGS SCN and time stamp.。
Examine the following scenario: - Database is running in ARCHIVELOG mode. - Complete consistent backup is taken every Sunday. - On Tuesday the instance terminates abnormally because the disk on which control files are located gets corrupted - The disk having active online redo log files is also corrupted. - The hardware is repaired and the paths for online redo log files and control files are still valid. Which option would you use to perform the recovery of database till the point of failure?（） Restore the latest whole backup, perform complete recovery, and open the database normally。 Restore the latest whole backup, perform incomplete recovery, and open the database with the RESETLOGS option.。 Restore the latest backups control file, perform complete recovery, and open the database with the RESETLOGS option.。 Restore the latest backup control file, perform incomplete recovery using backup control file, and open the database with the RESETLOG option.。
Full Atomicity, Consistency, Isolation, Durability (ACID) compliance is a necessity for a new application, which heavily reads and writes data.
This requires the following config file options: Sync_binlog=1 Innodb_flush_log_at_trx_commit=1 Innodb_doublewrite=1 However, this configuration is expected to introduce disk I/O overhead.
What three changes will reduce disk I/O overheads?（）
