Manageability and Performance
Advanced LOW IOT Compression
An index-organized table (IOT) is a table stored in a variation of a B-tree index structure where rows are ordered by primary key. IOTs are useful because they provide fast random access by primary key without duplicating primary key columns in two structures – a heap table and an index. In earlier releases, IOTs only supported Oracle's prefix compression (formerly called key compression), which required additional analysis and had the possibility of negative compression (where the overhead of compression outweighed the compression benefits).
Advanced LOW IOT Compression allows you to reduce the overall storage for Oracle Databases.
Automatic SecureFiles Shrink for Autonomous Database
Automatic SecureFiles Shrink for Autonomous Database automatically selects SecureFiles LOB segments based on a set of criteria and executes the free space shrink operation in the background for the selected segments. With Automatic SecureFiles Shrink and Autonomous Database, the shrink operation happens transparently in small and gradual steps over time while allowing DDL and DML statements to execute concurrently. In the manual method, you must decide on which LOB segments to shrink using tools like Segment Advisor and use a DDL statement to execute the shrink operation. The manual method may not be feasible for very large LOB segments because it is time-consuming.
Automatic SecureFiles Shrink for Autonomous Database simplifies administrator duties and saves time due to the automation of this process.
Automatic Storage Compression
Organizations use Hybrid Columnar Compression for space saving and fast analytics performance. However, the compression and decompression overhead of Hybrid Columnar Compression can affect direct load performance. To improve direct load performance, Automatic Storage Compression enables Oracle Database to direct load data into an uncompressed format initially, and then gradually move rows into Hybrid Columnar Compression format in the background.
Automatic Storage Compression improves direct load performance, while keeping the advantages of Hybrid Columnar Compression, including space savings and fast analytics performance.
DBCA Silent Options Changes
DBCA silent mode options changes in various functionality
DBCA silent command line options integrate smoothly with custom scripts and provide user-friendly errors.
Enhanced Query History Tracking and Reporting
Enhanced Query History Tracking and Reporting lets you track and report on a more complete history of user-issued queries than is available in previous releases. This feature provides you with greater capability to track user-initiated queries within a session. It includes non-parallel queries with less than five seconds of execution time, which are not tracked with Real-time SQL Monitoring unless tracking is forced by a hint. Each user can access and report on their own current session history. SYS users and DBAs can view and get query history reports for all current user sessions and can also turn this functionality on or off. Reporting is configurable, with options for selecting the reporting scope and detail level.
Enhanced Query History Tracking and Reporting allows application developers and development operations (DevOps) personas to get detailed insight into the queries that execute on your databases. This insight allows you to better manage and optimize your applications.
Fast Ingest (Memoptimize for Write) Enhancements
This feature adds enhancements to Memoptimize Rowstore Fast Ingest with support for partitioning, compressed tables, fast flush using direct writes, and direct In-Memory column store population support. These enhancements make the Fast Ingest feature easier to incorporate in more situations where fast data ingest is required.
This feature helps Oracle Database provide better support for applications requiring fast data ingest capabilities. Data can be ingested and then processed all in the same database. This reduces the need for special loading environments, and thus reduces complexity and data redundancy.
Improved Performance of LOB Writes
You can experience improved read and write performance for LOBs due to the following enhancements:
- Multiple LOBs in a single transaction are buffered simultaneously. This improves performance when you use switch between LOBs while writing within a single transaction.
- Various enhancements, such as acceleration of compressed LOB append and compression unit caching, improve the performance of reads and writes to compressed LOBs.
- The input-output buffer is resized based on the input data for large writes to LOBs with the NOCACHE option. This improves the performance for large direct writes, such as writes to file systems on DBFS and OFS.
This feature adds a host of improvements to accelerate SecureFiles writes for JSON document-based applications, for write calls issued by a database file system, and also for LOB workloads where the underlying data is compressed for storage savings.
Improved System Monitor (SMON) Process Scalability
Queries can require large amounts of temporary space and some temporary space operations run in critical background processes, like the System Monitor (SMON) process. SMON is responsible for cleaning up temporary segments that are no longer in use. SMON checks regularly to see whether it is needed, and other processes can call SMON. Temporary space management can affect SMON's scalability for other critical actions. This new enhancement instead uses the Space Management Coordinator (SMCO) process so that the responsibility of managing temporary space is offloaded from SMON, thereby improving its scalability.
This feature improves the overall scalability of the SMON process, particularly in a multitenant Oracle RAC cluster.
Migrate BasicFile LOBs Using the SecureFiles Migration Utility
You can use the SecureFiles Migration Utility to simplify the migration and compression of BasicFile LOB segments to SecureFiles LOB segments.
Earlier it was challenging to decide which BasicFile LOBs to migrate to SecureFile LOBs, and whether or not to compress the LOBs, especially considering that organizations often have many databases, with a large numbers of schemas, tables, and segments. SecureFiles Migration Utility automates several steps that were earlier performed manually. It also generates several reports that help you decide which BasicFile LOBs you want to migrate and compress.
Ordered Sequence Optimizations in Oracle RAC
The processing of ordered sequences in Oracle Real Application Clusters (Oracle RAC) has been optimized to provide better performance without requiring manual changes, ensuring a strict sequence order.
Applications using ordered sequences in Oracle RAC environments will benefit from improved performance and scalability.
Pluggable Database Support in Oracle Data Guard Environments
There is now a pluggable database configuration in a Data Guard environment using Database Configuration Assistant (DBCA).
A command line based silent mode option is available for configuring pluggable databases (PDBs) in Data Guard environments.
Refreshable PDBs in DBCA
Database Configuration Assistant (DBCA) allows you to clone a remote Pluggable database (PDB) as a refreshable PDB. When a PDB is created as refreshable, the changes of the source PDB will periodically propagate to the refreshable PDB. The refreshable PDB can be configured to refresh manually or automatically during creation.
A DBCA-based graphical user interface or scripted silent mode for cloning a remote refreshable PDB reduces many commands needed to create a remote refreshable PDB clone ensuring a faster and more reliable cloning of PDBs.