Database Management Systems

SqlSessionFactory is created using SqlSessionFactoryBuilder in iBATIS/MyBatis. This builder pattern reads configuration and builds the factory. Other options like SqlBuilder or SqlSessionBuilder are incorrect or don't exist.

The statement claims iBATIS discourages SQL use, but this is false - iBATIS is designed to leverage SQL's power. It allows developers to write raw SQL queries while simplifying database access, preserving all SQL benefits. Therefore the correct answer is False.

In Oracle, when the listener is down but the instance is up, local connections using IPC/bequeath protocol still work. Remote connections require the listener to establish the initial connection.

The physical nature of an IMS database is defined by the DBD (Database Description). The DBD describes the physical structure of the database including segment layout, field definitions, and indexing information. IO-PCB and IO-AREA are runtime structures used during program execution, while SSA is a navigation parameter.

The Automatic Workload Repository (AWR) is the Oracle component that stores statistics collected by the MMON (Manageability Monitor) process. AWR serves as the foundation for performance diagnostics and contains detailed performance statistics. ADDM uses AWR data for its analysis but is the diagnostic tool itself, not the storage mechanism. Data dictionary views and dynamic performance views are different database structures.

When a SQL statement causes I/O issues, both SQL Tuning Advisor and SQL Access Advisor are relevant. SQL Tuning Advisor optimizes the SQL statement itself (indexes, statistics, SQL structure), while SQL Access Advisor focuses on access paths and materialized views. Using both provides comprehensive troubleshooting for I/O problems caused by SQL statements.

When submitting advisor analysis jobs, the 'Limited' scope adds the least overhead because it performs minimal analysis. 'Restricted' is not a valid job scope option in this context. 'Comprehensive' and 'Thorough' (though 'Thorough' is not standard Oracle terminology) would involve deeper analysis with more system overhead. Limited scope is the lightweight option for minimal system impact.

DBA_ADVISOR_RATIONALE is the view that contains the reasoning and justification behind ADDM recommendations. It explains WHY specific recommendations were made. DBA_ADVISOR_FINDINGS shows what problems were discovered, DBA_ADVISOR_OBJECTS lists affected objects, and DBA_ADVISOR_RECOMMENDATIONS contains the suggested solutions - but RATIONALE provides the explanatory reasoning.

The Memory Advisor in Oracle determines if allocated memory for Shared Pool, Large Pool, and Buffer Cache is adequate. It analyzes memory usage patterns and provides recommendations for SGA component sizing. SQL Tuning Advisor focuses on SQL optimization, not memory allocation. SGA Tuning Advisor and Pool Advisor are not standard Oracle advisor names.

The MTTR (Mean Time To Recover) Advisor evaluates if the estimated instance recovery duration meets service-level agreement requirements. It analyzes Redo log file sizing and configuration to optimize recovery time. Undo Management Advisor focuses on undo tablespace management, while SQL Access and Tuning Advisors deal with SQL optimization - not recovery time estimation.

The SQL Tuning Advisor is the appropriate first tool for analyzing and improving performance of a specific SQL statement showing high disk I/O. The SQL Access Advisor is for overall schema design (indexes/materialized views), not individual statement tuning. The main screen and alert log are for monitoring, not targeted SQL optimization.

The Performance screen in EM Database Control is the primary location to investigate sudden performance degradation, as it provides detailed metrics on wait events, throughput, and resource utilization. The Administration and Maintenance screens are for configuration and maintenance tasks, not performance diagnostics. The main screen only shows high-level alerts.

By default, AWR (Automatic Workload Repository) retains database statistics for 7 days. This is the standard retention period for automatic workload repository snapshots. 30 days is not the default, and 7 hours is too short. Statistics are not retained indefinitely by default.

The three primary sources of performance metrics in the EM Performance screen are Host (operating system metrics), Session (user session activity), and Instance (database instance statistics). Network metrics are not one of the three primary sources - they may be available but are not fundamental to the Performance screen's three-tier view.

Only databases created using the Database Configuration Assistant (DBCA) automatically have the statistics collection job configured. When you create databases manually with scripts, the automatic statistics collection procedure is not set up by default. This is a documented behavior, not a parameter or login issue.