5 New Features for Oracle Exadata System Software Release 21.x

This section describes the new features introduced in Oracle Exadata System Software release 21.x.

• What's New in Oracle Exadata System Software Release 21.2
  

5.1 What's New in Oracle Exadata System Software Release 21.2

• Oracle Exadata X9M Support
  
• Persistent Storage Index
  
• Persistent Columnar Cache
  
• IORM Cluster Plan
  
• Smart Scan Metadata Sharing
  
• Oracle ASR Support for Cisco RoCE Network Fabric Switches and Management Network Switch
  
• Patch Manager Support for the Management Network Switch
  
• Options to Preserve Redundancy while Dropping a Physical Disk
  
• Faster Upgrades with ILOM Pre-Staging
  
• Faster Recovery from Flash Cache Failure
  
• Automatic Recovery from Disk Controller Cache Failure
  
• Enhanced Database Server Alerting
  
• Oracle ACFS I/O Caching in Flash Cache
  
• Smart Scan Fast Decryption
  
• Caching Flashback Log Writes in Exadata Smart Flash Cache
  
• Deprecated Features in Oracle Exadata System Software Release 21.2
  

5.1.1 Oracle Exadata X9M Support

Oracle Exadata System Software release 21.2.0 introduces support for the Oracle Exadata X9M system family.

Exadata X9M is the second generation of system hardware based on RoCE Network Fabric, and offers performance and capacity improvements throughout.

See Hardware Components of Oracle Exadata Database Machine in the Oracle Exadata Database Machine System Overview for details.

Minimum requirements:

• Oracle Exadata System Software release 21.2.0
• Oracle Exadata X9M

5.1.2 Persistent Storage Index

Storage indexes help Oracle Exadata System Software to avoid unnecessary I/O operations. By avoiding unnecessary I/O, affected operations perform better. Also, overall system throughput increases because the saved I/O bandwidth can be used to perform other work.

Oracle Exadata System Software creates and maintains a storage index in shared memory on Exadata Storage Server. For each storage region, the storage index automatically tracks minimum and maximum column values and set membership. Storage index functionality works transparently with no user input. There is no need to create, drop, or tune the storage index.

Starting with Oracle Exadata System Software release 21.2.0, the storage index can persist across cell restarts and upgrades. When the feature is enabled, the storage index shared memory segments are written to the storage server system disks during a graceful shutdown, and these are automatically restored during restart. In the event of a cell server crash or offload server crash, the storage index shared memory segments are retained by the operating system and are immediately available when the software service restarts.

On Oracle Exadata Database Machine X7-2 and later systems with M.2 solid-state drives (SSD), persistence can also be maintained across Oracle Exadata System Software upgrades.

This feature eliminates the need to rebuild the storage index and enables more consistent query performance immediately after a cell restart.

The feature is controlled by setting the storageIndexPersMode cell attribute.

Minimum requirements:

• Oracle Exadata System Software release 21.2.0
• Oracle Database 12c Release 2 (12.2)

5.1.3 Persistent Columnar Cache

The columnar cache is a portion of Exadata Smart Flash Cache that contains data in columnar format. Data in Exadata Smart Flash Cache is automatically converted to columnar format and stored in the columnar cache to aid query performance.

Before Oracle Exadata System Software release 21.2.0, metadata for managing the columnar cache is lost when the cell fails or shuts down. Consequently, the columnar cache must be rebuilt following each cell restart.

Starting with Oracle Exadata System Software release 21.2.0, the columnar cache can persist across cell restarts and upgrades. This feature saves resources associated with rebuilding the cache and enables more consistent query performance immediately after a cell restart.

To use persistent columnar cache, Exadata Smart Flash Cache must be in Write-Back mode. The feature is controlled by setting the columnarCachePersMode cell attribute.

Minimum requirements:

• Oracle Exadata System Software release 21.2.0

5.1.4 IORM Cluster Plan

Oracle Exadata System Software release 21.2.0 extends I/O Resource Management (IORM) to include the cluster plan. The IORM cluster plan specifies how storage server resources are allocated across multiple Oracle Grid Infrastructure clusters. Each directive in a cluster plan specifies an allocation to an Oracle Grid Infrastructure cluster, rather than an individual database or consumer group.

For example, consider a system hosting two clusters; clusterA and clusterB. Now, imagine a cluster plan with share-based resource allocation where clusterA has three shares, and clusterB has one share. In that case, and in the absence of any other IORM plans, all of the databases running in clusterA share 75% of the I/O resources, while the databases in clusterB share the remaining 25%.

Minimum requirements:

• Oracle Exadata System Software release 21.2.0
• To operate the IORM cluster plan, ASM-scoped security must be configured.

5.1.5 Smart Scan Metadata Sharing

During Smart Scan operations, Oracle Database sends query metadata to the Exadata Storage Servers. The query metadata contains information like predicated columns, projected columns, predicates, database session information, bloom filters, and so on, which is required to offload the query to the storage servers. Historically, during parallel query execution, each Oracle Database parallel query server process sends serialized and compressed query metadata to the storage server, where it is uncompressed and deserialized before use. Furthermore, for each parallel query, a significant portion of the metadata is common to all of the parallel query server processes.

Starting with release 21.2.0, Oracle Exadata System Software shares common query metadata across Smart Scan sessions belonging to the same parallel query. This feature reduces the memory and processing footprint for parallel queries in Exadata Storage Server. In turn, the saved resources can support other work and increase the overall system throughput. The benefit is greatest for sophisticated operations that typically require more metadata, such as join queries using Bloom filters, data mining models, external tables, and tables with JSON/XML types.

Minimum requirements:

• Oracle Exadata System Software release 21.2.0

5.1.6 Oracle ASR Support for Cisco RoCE Network Fabric Switches and Management Network Switch

Oracle Exadata System Software release 21.2.0 introduces new capabilities to monitor Cisco switches using Oracle Auto Service Request (ASR). This capability covers the Cisco Management Network Switch and RoCE Network Fabric Switches present in X8M and later systems. It also covers Management Network Switch model 9348 present in earlier X8 and some X7 systems.

With this release, when you use the Patch Manager utility (patchmgr) to upgrade the Cisco switch firmware, a new monitoring component is also installed on the Cisco switch. The new monitoring component propagates switch alerts to Oracle ASR, enabling automated problem detection and resolution.

Minimum requirements:

• Oracle Exadata System Software release 21.2.0
• Oracle Exadata Database Machine X8M, or earlier models with Cisco Management Network Switch model 9348.

5.1.7 Patch Manager Support for the Management Network Switch

Commencing with Oracle Exadata System Software release 21.2.0, the Patch Manager utility (patchmgr) introduces capabilities to manage firmware upgrades on the 9000 series Management Network Switch found on Oracle Exadata Database Machine X7-2 and later systems.

Minimum requirements:

• Oracle Exadata System Software release 21.2.0
• Oracle Exadata Database Machine X7-2

5.1.8 Options to Preserve Redundancy while Dropping a Physical Disk

Oracle Exadata System Software release 21.2.0 introduces the MAINTAIN REDUNDANCY and NOWAIT options to the CELLCLI ALTER PHYSICALDISK DROP FOR REPLACEMENT command.

The MAINTAIN REDUNDANCY option streamlines Exadata Storage Server administration by automatically rebalancing data before dropping the corresponding ASM disks. In previous releases, maintaining redundancy required additional administrator intervention to manually drop the corresponding ASM disks and rebalance the data prior to using the ALTER PHYSICALDISK DROP FOR REPLACEMENT command.

The NOWAIT option allows the ALTER PHYSICALDISK command to complete immediately while the DROP FOR REPLACEMENT operation runs asynchronously in the background.

Minimum requirements:

• Oracle Exadata System Software release 21.2.0

5.1.9 Faster Upgrades with ILOM Pre-Staging

The upgrade process for Oracle Exadata System Software typically includes a firmware upgrade for Integrated Lights Out Manager (ILOM). Historically, the ILOM firmware upgrade was performed as a serial process, taking approximately 30% of the total software upgrade time on each physical server (database server or storage server).

ILOM version 5 introduces support for pre-staging of new ILOM firmware. With this feature, pre-staging occurs in parallel with other server upgrade activities, and the new ILOM firmware is automatically enabled when the server reboots at the end of the upgrade procedure.

On Exadata X7 and newer systems, this approach approximately halves the ILOM firmware upgrade time on each server, which translates to an improvement of approximately 15% for the total software upgrade time.

Minimum requirements:

• This feature is automatically used on Exadata X7 and newer systems, except for X8-2L servers, when upgrading Oracle Exadata System Software from at least version 19.3.11 or 20.1.1.

• For X8-2L servers only, this feature is automatically used when upgrading Oracle Exadata System Software from at least version 19.3.12 or 20.1.2.

5.1.10 Faster Recovery from Flash Cache Failure

This feature reduces the recovery time following flash cache failure by staging flash cache metadata to the M.2 solid-state drives (SSD) found on Oracle Exadata Database Machine X7 and later systems. Using the M.2 SSD speeds up resilvering table creation and the assignment of caching devices following flash failure. This feature reduces the overall brownout time following a flash failure.

Minimum requirements:

• Oracle Exadata System Software release 21.2.0
• Oracle Exadata Database Machine X7-2

5.1.11 Automatic Recovery from Disk Controller Cache Failure

High Capacity (HC) and Extended (XT) Oracle Exadata Storage Server models have a disk controller that contains a write-back cache, which is separate and distinct from the write-back flash cache.

A multiple-bit ECC error on the disk controller cache can crash the server, resulting in the loss of unflushed data in the disk controller cache and leaving stale data on the disks. If not handled carefully, such errors are severe and can result in data loss.

Oracle Exadata System Software release 21.2.0 supports automatic recovery following a disk controller cache failure. Where possible, this feature automatically detects the problem and copies data from other mirrors to recover all of the disks in the failed server.

Minimum requirements:

• Oracle Exadata System Software release 21.2.0

5.1.12 Enhanced Database Server Alerting

Oracle Exadata System Software release 21.2.0 introduces enhanced alerting on the database servers.

With this capability, the DBMCLI LIST ALERTHISTORY command now shows incidents relating to Oracle Grid Infrastructure and Oracle Database software.

Minimum requirements:

• Oracle Exadata System Software release 21.2.0

5.1.13 Oracle ACFS I/O Caching in Flash Cache

To optimize I/O efficiency, small sequential writes to Oracle Advanced Cluster File System (Oracle ACFS) are automatically combined into 1 MB chunks. However, before Oracle Exadata System Software release 21.2.0, these larger writes would bypass the cache and go directly to disk.

Commencing with Oracle Exadata System Software release 21.2.0, all Oracle ACFS I/O is eligible for caching in Exadata Smart Flash Cache.

This feature enhances Oracle ACFS performance, especially for applications such as Oracle GoldenGate trail files, having an I/O profile dominated by small sequential writes and fast subsequent reads.

Minimum requirements:

• Oracle Exadata System Software release 21.2.0

5.1.14 Smart Scan Fast Decryption

In conjunction with applicable hardware first introduced in Oracle Exadata X9M, Oracle Exadata System Software release 21.2.0 uses VAES and AVX512 instruction sets and implements cache-friendly algorithms to improve Smart Scan performance on encrypted tables and compressed tables.

Minimum requirements:

• Oracle Exadata System Software release 21.2.0
• Oracle Exadata X9M

5.1.15 Caching Flashback Log Writes in Exadata Smart Flash Cache

Building on optimizations introduced in Exadata System Software 12.2.1.1.0 that enable Faster Performance for Large Analytic Queries and Large Loads, this release automatically caches flashback log writes, which can significantly improve flashback database performance.

5.1.16 Deprecated Features in Oracle Exadata System Software Release 21.2

The following features are deprecated in this release, and may be desupported in a future release:

• Deprecation of RAM Cache
  
• Deprecation of USB Images
  
• Deprecation of the IORM Category Plan
  

5.1.16.1 Deprecation of RAM Cache

Commencing with the September 2022 Oracle Exadata System Software release updates (versions 21.2.16 and 22.1.3), the cell RAM Cache feature is deprecated.

Existing RAM Cache installations continue to operate as they did in previous releases. However, new RAM Cache creation requests are not allowed after the deprecation.

The cell RAM Cache feature was introduced in Oracle Exadata System Software version 18.1.0. See In-Memory OLTP and Consolidation Acceleration.

5.1.16.2 Deprecation of USB Images

Commencing with the September 2022 Oracle Exadata System Software release updates (versions 21.2.16 and 22.1.3), USB images are deprecated.

After the deprecation, USB images are no longer available for imaging or re-imaging an Oracle Exadata Database Machine server and are not included in the Secure Eraser package (secureeraser_label.zip). Instead of USB image files, use the PXE option with ISO image files.

5.1.16.3 Deprecation of the IORM Category Plan

Starting with Oracle Exadata System Software release 21.2.0, the Exadata I/O Resource Management (IORM) category plan (catplan) is deprecated, and a warning message is issued when a category plan is specified.