Database Architecture
Lock-Free Reservation
The Lock-Free Reservation feature enables concurrent transactions to proceed without being blocked on updates of heavily updated rows. A Lock-Free Reservation is held on the row, instead of locking the row. The Lock-Free Reservation verifies if the updates can succeed and defers the updates until the transaction commit time.
Lock-Free Reservation improves the end user experience, and concurrency, in transactions.
Wide Tables
The maximum number of columns allowed in a database table or view has been increased to 4096. This feature allows you to build applications that can store attributes in a single table with more than the previous 1000-column limit. Some applications, such as Machine Learning and streaming IoT application workloads, may require the use of de-normalized tables with more than 1000 columns.
You now have the ability to store a larger number of attributes in a single row which for some applications may simplify application design and implementation.
Consolidated Service Backgrounds for Oracle Instance
We are introducing a new set of service processes which execute database service actions.
Service actions are responsible for maintenance tasks, parallel tasks and brokered tasks, consolidated tasks and many more. These were performed by dedicated processes in the database before. The new background scheduler group processes can execute any of these service actions, thus providing consolidation of background service actions.
Improve Performance and Disk Utilization for Hybrid Columnar Compression
Enhancements to the compression algorithms for Hybrid Columnar Compression (HCC) include improvements for faster compression and decompression speeds, as well as better compression ratios for newly created HCC compressed tables or for existing HCC compressed tables that are rebuilt. The exact benefits can vary based on the data and the chosen compression level.
This feature improves an application's workload performance while reducing database storage utilization.
Migrating LOBs Made Easier
The number of steps required to migrate and compress BasicFile LOB segments to SecureFiles LOB segments, using SecureFiles Migration Utility, have been reduced.
This enhancement simplifies the process to migrate LOB segments.
Optimized Oracle Native Access to NVMe Devices Over Fabric
Starting with Oracle AI Database 26ai, you can use TCP/IP network connections to access the remote NVMe storage devices using NVMe over Fabrics (NVMe-oF). The Oracle Grid Infrastructure server works as an initiator that connects to an NVMe-oF storage target created using Linux Kernel nvmet_tcp module, providing optimized user mode access to remote NVMe devices.
NVMe-oF provides a low-latency and secure way to access remote NVMe devices exported using NVMe Over Fabrics target. Oracle provides an optimized way to access these NVMe-oF devices directly from an Oracle process. This Oracle-native method of accessing NVMe-oF devices reduces latency while Oracle ASM makes storage manageability easier.
Oracle DBCA Support for PMEM Storage
Oracle Database Configuration Assistant (Oracle DBCA) enables you to select persistent memory database (PMEM) as your storage option when creating a single-instance database.
This feature automates the process of assigning a PMEM device for your database storage enabling you to place database files in a PMEM storage device.
Partition by Expression
Partition by expression allows you to define a partition key using an expression directly in the partitioning clause. This eliminates the need for creating a separate virtual column solely to serve as the partition key, streamlining schema design.
This feature simplifies DDL and maintenance by removing the overhead of managing virtual columns, while making partitioning definitions more intuitive and expressive. It gives developers more flexibility to partition on derived values (dates, substrings, JSON fields, etc.) with less schema clutter.
Simplifying Data Integrity Using Assertions
An assertion allows the user to define business rules on one or more tables so that DMLs on the table(s) will always honor those rules. Current solutions, such as check constraints and triggers, have limits. Check constraints only work at the column or row level. Triggers, while table-level, need complex PL/SQL and careful management for multi-table cases. With assertions, developers use a clear, declarative syntax to embed business logic directly in the database.
This feature reduces the risk of inconsistent data and eliminates redundant validation code across applications. Assertions also resolve concurrency and serialization issues by default. When business rules change, updating a single assertion is faster and less error-prone than editing many codebases.
System Timezone Autonomy for Pluggable Databases
Oracle Multitenant enables Oracle AI Database to consolidate multiple pluggable databases as self-contained databases, improving resource utilization and database management. In addition to providing a fully centrally managed database environment with identical, global time zone settings for all pluggable databases (impacting SYSDATE and SYSTIMESTAMP), pluggable databases can now control their time zone settings independently. You can control the time zone setting, including internal processes and operations, or only on a user-visible level.
The ability to control the time zone behavior for SYSDATE and SYSTIMESTAMP on a pluggable database level increases to self-containment of individual databases in a multitenant environment and enhances your consolidation capabilities of independent databases.
Unrestricted Direct Loads
Prior to this feature, after a direct load and prior to a commit, queries and additional DMLs were not allowed on the same table for the same session or for other database sessions. This enhancement allows the loading session to query and perform DML on the same table that was loaded. Rollback to a savepoint is also supported.
This feature removes the restrictions that you may have encountered when loading and querying data. Potentially improving the performance of your applications in areas such as Data Warehousing and complex batch processing.