You notice a high number of waits for the db file scattered read and db file sequential read events in the recent Automatic Database Diagnostic Monitor (ADDM) report. After further investigation, you find that queries are performing too many full table scans and indexes are not being used even though the filter columns are indexed. Identify three possible reasons for this.（） Missing or stale histogram statistics。 Undersized shared pool。 High clustering factor for the indexes。 High value for the DB_FILE_MULTIBLOCK_READ_COUNT parameter。 Oversized buffer cache。
两台变压器并列运行时，如果其他条件相同，只有短路电压不同，则（）。 短路电压大的变压器带负荷多。 短路电压小的变压器带负荷多。 两台负荷一样多。
A PL/SQL procedure queries only those columns of a redefined table that were unchanged by the online table redefinition. What happens to the PL/SQL procedure after the online table redefinition？（） It remains valid.。 It becomes invalid for all options of online table redefinition but automatically gets revalidated the next time it is used.。 It becomes invalid for all options of online table redefinition and is automatically recompiled during online redefinition of the table.。 It becomes invalid only if the storage parameters have been modified and it automatically gets revalidated the next time it is used.。
In your test database， you find that a user’s session is executing a lot of SQL statements， resulting in the generation of a large number of trace files. While investigating the reason， you find that SQL trace has been enabled at the instance level. You want to disable SQL trace， remotely， only for that user session to reduce the volume of trace data being generated.How do you achieve this objective？（） by setting the SQL_TRACE parameter to FALSE in the parameter file。 by using DBMS_MONITOR.SESSION_TRACE_DISABLE to disable the tracing for the user session。 by setting the SQL_TRACE parameter to FALSE by using the ALTER SYSTEM command in the user session。 by setting the SQL_TRACE parameter to FALSE by using the ALTER SESSION command in the user sessio。
在使用断管设备时要保证（） 切割车刀的锋利。 设备运行的平稳。 切割铣刀的锋利。 链条的节数随被且切管变化。
Which two Oracle products come pre-packaged with Oracle’s JRockit JDK ？（）
