Oracle DBA

Oracle 19c introduced several new features and enhancements over Oracle 12c for database administrators. Here are some key features:

1. Multitenant Architecture: Oracle 19c extends the multitenant architecture introduced in Oracle 12c, allowing administrators to manage multiple pluggable databases as a single container database. This architecture provides improved resource utilization, simplified database consolidation, and easier management.
2. Automatic Indexing: Oracle 19c introduces the Automatic Indexing feature, which automates the creation, monitoring, and dropping of indexes based on the database workload. This feature helps optimize query performance without manual intervention.
3. Real Application Clusters (RAC) Improvements: Oracle 19c enhances the RAC feature with several improvements, including faster cluster node recovery, enhanced workload management, and improved diagnostics for troubleshooting cluster issues.
4. Online Partition Merge and Move: In Oracle 19c, you can perform online partition merge and move operations, allowing you to reorganize and manage partitions without interrupting database availability. This feature simplifies maintenance tasks and reduces downtime.
5. Memory Management: Oracle 19c introduces several enhancements to memory management, including support for automatic memory management for In-Memory Column Store, Dynamic Statistics, and Adaptive Features. These improvements optimize memory allocation and utilization for better performance.
6. SQL Quarantine: This feature helps protect the database from SQL statements that consume excessive system resources or cause performance issues. Oracle 19c can automatically quarantine problematic SQL statements, preventing them from impacting the overall system performance.
7. Enhanced Real-Time Statistics: Oracle 19c improves real-time statistics gathering, allowing the optimizer to make more accurate decisions based on up-to-date statistics. This feature enhances query performance and overall database efficiency.
8. Security Enhancements: Oracle 19c includes several security enhancements, such as the ability to encrypt sensitive data across different databases using the same encryption key, enhanced password security, and improved security for application development.

These are just some of the new features and enhancements introduced in Oracle 19c over Oracle 12c. It’s important to note that Oracle regularly releases patch sets and updates, so there may be additional features and improvements beyond the initial 19c release.

Multitenant Architecture enhancement

In Oracle 19c, the Multitenant Architecture, which was introduced in Oracle 12c, has been enhanced with several improvements. Here are some of the key enhancements:

1. Hot Clone PDB: In Oracle 19c, you can create a hot clone of a pluggable database (PDB) without shutting down the source PDB. This enables faster provisioning and cloning of PDBs for testing, development, or backup purposes
2. PDB Archive Files: Oracle 19c allows you to move a PDB along with its data files to a different file system using PDB archive files. This feature simplifies PDB relocation and reduces downtime during PDB migration
3. PDB Refresh: With the PDB refresh feature, you can quickly and easily refresh the data in a PDB from a snapshot copy of the source PDB. This simplifies the process of creating and maintaining consistent development and testing environments.
4. PDB Snapshot Carousel: Oracle 19c introduces the PDB snapshot carousel feature, which enables you to retain and manage a history of PDB snapshots. This allows you to easily roll back to a previous point-in-time snapshot of a PDB if needed
5. PDB Stateless Mode: In Oracle 19c, you can run a PDB in a stateless mode, where the PDB does not store any persistent data. This mode is useful for scenarios where you need to create temporary or transient databases, such as for parallel processing or temporary data storage
6. Cross-Container Queries: Oracle 19c enhances the cross-container queries feature, allowing you to execute queries that span multiple PDBs within the same container database (CDB). This enables efficient data analysis and reporting across multiple PDBs
7. Resource Manager for PDBs: The Resource Manager feature in Oracle 19c now provides finer-grained control and allocation of resources for PDBs. You can allocate CPU, memory, and other resources to individual PDBs based on their specific workload requirements.

These enhancements in Oracle 19c’s Multitenant Architecture provide improved flexibility, manageability, and efficiency when working with pluggable databases. They offer more options for provisioning, cloning, managing resources, and controlling data movement within a multitenant environment.

Automatic indexing enhancement

Automatic Indexing is a significant feature that was introduced in Oracle 19c to automate the creation, management, and optimization of indexes in a database. While the core functionality of Automatic Indexing was introduced in Oracle 12c, Oracle 19c brought several enhancements to this feature. Here are some key enhancements in Automatic Indexing in Oracle 19c:

1. Auto Indexing Enabled by Default: In Oracle 19c, Automatic Indexing is enabled by default, making it easier to leverage the benefits of this feature without manual intervention. The system automatically identifies and creates indexes to improve query performance.
2. Auto Indexing Advisor: Oracle 19c introduces the Auto Indexing Advisor, which provides recommendations for indexes that can be created to improve query performance. This advisor analyzes the database workload and suggests potential indexes based on the query patterns and execution plans.
3. Priority-Based Auto Indexing: In Oracle 19c, you can assign priority levels to different workloads, allowing you to prioritize the automatic indexing process based on critical applications or high-priority queries. This helps ensure that resources are allocated appropriately for index creation and maintenance.
4. Auto Indexing Report: Oracle 19c includes an Auto Indexing report that provides insights into the automatic indexing activities. The report includes information on newly created indexes, dropped indexes, and their impact on query performance. It helps administrators understand the effectiveness of automatic indexing and make informed decisions.
5. Auto Indexing Exclusion: Oracle 19c allows you to exclude specific tables or indexes from the automatic indexing process. This is useful when you want to avoid automatic index creation for certain objects or if you prefer to manually manage indexing for specific tables.
6. Auto Indexing DML Monitoring: In Oracle 19c, Automatic Indexing can monitor the data modification activities (DML) on the indexed tables and adjust the indexes accordingly. This ensures that the indexes remain optimized even when there are frequent changes to the underlying data.
7. Maintenance Window Flexibility: Oracle 19c provides more flexibility in defining the maintenance window for automatic index tasks. You can specify the window during which the system can perform index maintenance operations, minimizing the impact on database availability during peak hours.

These enhancements in Oracle 19c’s Automatic Indexing feature help streamline the index management process, improve query performance, and provide better control and visibility into the automatic indexing activities in the database.

Real Application Clusters(RAC) enhancement

Oracle 19c introduced several enhancements to the Real Application Clusters (RAC) feature, which enables high availability and scalability for Oracle databases. Here are some key enhancements in RAC for Oracle 19c:

1. Faster Cluster Node Recovery: Oracle 19c improves the cluster node recovery process, reducing the downtime required for node failures and restarts. The fast cluster node recovery ensures that the affected instances can quickly rejoin the cluster and resume normal database operations.
2. Enhanced Workload Management: Oracle 19c enhances workload management in RAC by introducing workload-specific resource plans. This allows you to allocate resources more effectively based on different workloads, ensuring that critical applications receive the necessary resources while maintaining overall system performance.
3. Improved Clusterware Diagnostics: Oracle 19c provides enhanced diagnostics and troubleshooting capabilities for RAC environments. The Cluster Health Advisor (CHA) in Oracle 19c offers improved diagnostics and automated health checks for the clusterware, helping administrators identify and resolve potential issues more efficiently.
4. Flex ASM: Oracle Flex ASM, introduced in Oracle 12c, allows for more flexible ASM deployment options within a RAC environment. In Oracle 19c, Flex ASM is further enhanced to provide better flexibility, scalability, and performance by allowing ASM instances to run on different nodes, independent of the database instances.
5. RAC Rolling Upgrades: Oracle 19c introduces enhancements to the rolling upgrade process for RAC environments. Rolling upgrades allow you to perform upgrades to Oracle Database software and apply patches without interrupting database availability. Oracle 19c simplifies the process and provides better support for rolling upgrades in RAC environments.
6. Application Continuity Improvements: Oracle 19c enhances Application Continuity, a feature that masks outages from end-users during planned or unplanned database outages. Oracle 19c improves the accuracy of replaying client requests, providing better continuity and reducing the impact of interruptions on application users.
7. Cluster Health Monitor (CHM): The Cluster Health Monitor (CHM) in Oracle 19c is enhanced with additional metrics and diagnostic information, allowing for better monitoring and troubleshooting of RAC environments. The CHM provides comprehensive visibility into cluster health, performance, and resource utilization.

These enhancements in Oracle 19c’s Real Application Clusters feature improve the availability, performance, and manageability of RAC environments. They provide faster recovery, more effective workload management, better diagnostics, and improved compatibility for rolling upgrades, enabling smoother operations in highly available and scalable Oracle database clusters.

Online Partition Merge and Move enhancement

Oracle 19c introduced an important enhancement to the partitioning feature called Online Partition Merge and Move. This enhancement allows for the online reorganization and management of partitions without interrupting database availability. Here’s an overview of the Online Partition Merge and Move feature in Oracle 19c:

1. Partition Merge: In Oracle 19c, you can merge adjacent partitions of a table into a single partition without requiring any downtime or blocking user access to the table. The partition merge operation consolidates data and improves query performance by reducing the number of partitions. This feature is particularly useful when you have historical partitions that are no longer needed, and you want to consolidate them for better management and performance.
2. Partition Move: With the Partition Move feature in Oracle 19c, you can move a partition from one table to another or from one partitioned table to another partitioned table online. The move operation can be performed without any disruption to user access or database availability. This feature is helpful when you need to reorganize data across tables or partitioned tables for better organization, data archiving, or maintenance purposes.
3. Fine-Grained Data Movement: The Online Partition Merge and Move feature in Oracle 19c allows you to specify fine-grained criteria for the data movement. You can define filters or conditions to move or merge specific subsets of data, providing more flexibility and control over the reorganization process.
4. Data Compression and Index Maintenance: When performing partition merge or move operations, Oracle 19c automatically maintains the compression settings and index structures associated with the affected partitions. This ensures that the merged or moved partitions retain the appropriate compression and indexing characteristics, preserving the performance benefits and reducing the administrative effort.
5. Reduced Downtime and Administration: By enabling online partition merge and move, Oracle 19c minimizes the need for database downtime and eliminates the administrative complexity typically associated with partition reorganization. This enhancement simplifies the management of partitioned tables and allows for more efficient maintenance operations while ensuring continuous access to the data.

The Online Partition Merge and Move enhancement in Oracle 19c provides database administrators with a powerful tool for reorganizing and managing partitions without interrupting database availability. It offers flexibility, fine-grained control, and efficient data movement capabilities, enabling administrators to optimize the performance and organization of their partitioned tables.

Memory Management enhancement

Oracle 19c introduces several enhancements to memory management, offering improved efficiency and performance for database administrators. Here are some key memory management enhancements in Oracle 19c:

1. Automatic Memory Management for In-Memory Column Store (IMCS): In Oracle 19c, the In-Memory Column Store, which is used for fast access to frequently accessed data, now supports automatic memory management. This means that you can configure the IMCS to dynamically allocate and manage memory based on the workload and usage patterns, optimizing memory usage for improved performance.
2. Dynamic Statistics: Oracle 19c enhances dynamic statistics, which are statistics automatically collected and maintained by the database. Dynamic statistics help the optimizer make accurate decisions for query optimization. In Oracle 19c, dynamic statistics are automatically enabled for tables that have no or stale statistics, ensuring more accurate and up-to-date statistics for query optimization.
3. Adaptive Features: Oracle 19c introduces adaptive features that dynamically adjust database behavior based on runtime conditions and workload characteristics. One such feature is Adaptive Execution Plans, which allows the optimizer to adapt and change execution plans during query execution to improve performance based on the actual data and runtime conditions.
4. Memory Guard: In Oracle 19c, the Memory Guard feature helps prevent the database from running out of memory by protecting critical components and ensuring that they have sufficient memory resources. Memory Guard helps maintain database stability and prevents performance degradation due to memory constraints.
5. Shared Pool Size Advisor: Oracle 19c includes the Shared Pool Size Advisor, a tool that helps administrators determine the optimal size for the shared pool, which stores shared SQL and PL/SQL code. The advisor analyzes the workload and provides recommendations for the shared pool size, helping administrators allocate memory resources effectively.
6. Memory Resource Management for PDBs: In a multitenant environment, Oracle 19c enhances memory resource management by providing better control and allocation of memory resources to individual pluggable databases (PDBs). Administrators can allocate memory based on the specific workload requirements of each PDB, ensuring optimal performance and resource utilization.

These memory management enhancements in Oracle 19c enable better utilization of memory resources, improved query optimization, and dynamic adaptation to changing workload conditions. They contribute to enhanced performance, stability, and efficient resource allocation in Oracle database environments.