多项选择题
A. The optimizer automatically changes a plan during subsequent execution of a SQL statement if there is a huge difference in optimizer estimates and execution statistics.
B. The optimizer can re optimize a query only once using cardinality feedback.
C. The optimizer enables monitoring for cardinality feedback after the first execution of a query.
D. The optimizer does not monitor cardinality feedback if dynamic sampling and multicolumn statistics are enabled.
E. After the optimizer identifies a query as a re-optimization candidate, statistics collected by the collectors are submitted to the optimizer.
多项选择题 Which two statements are true about the Oracle Direct Network File system (DNFS)?（）
单项选择题 In your multitenant container database (CDB) with two pluggable database (PDBs). You want to create a new PDB by using SQL Developer. Which statement is true?（）
单项选择题 You are required to migrate your 11.2.0.3 database as a pluggable database (PDB) to a multitenant container database (CDB). The following are the possible steps to accomplish this task: 1. Place all the user-defined tablespace in read-only mode on the source database. 2. Upgrade the source database to a 12c version. 3. Create a new PDB in the target container database. 4. Perform a full transportable export on the source database with the VERSION parameter set to 12 using the expdp utility. 5. Copy the associated data files and export the dump file to the desired location in the target database. 6. Invoke the Data Pump import utility on the new PDB database as a user with the DATAPUMP_IMP_FULL_DATABASE role and specify the full transportable import options. 7. Synchronize the PDB on the target container database by using the DBMS_PDS.SYNC_ODB function. Identify the correct order of the required steps.（）