In 19c or higher, it is no longer necessary to enable ‘Shared Servers’ on the catalog database, so Oracle recommends that (if you are using Oracle Native Encryption with sharding) you disable Shared Servers on the catalog database. This can be done by setting the database parameter shared_servers to “0” and restarting Oracle. Note that this is a global parameter set in the Container Database.

Oracle Groundbreakers EMEA 2021
Michigan Oracle Users Summit 2021 –

Oracle Machine Learning for R (OML4R) is an R API that makes the open-source R statistical programming language and environment ready for enterprise and big data. Designed for significant data problems, OML4R integrates R with Oracle Database.
R users can run R commands and scripts for statistical and graphical analyses on data stored in the Oracle Database. In addition, they can develop, refine and deploy R scripts that leverage the parallelism and scalability of the database to automate data analysis.

For more information, see: https://docs.oracle.com/en/database/oracle/machine-learning/oml4r/1.5.1/tasks.html

There have been a few issues related to the grid inter-process communication(GIPC) daemon. Since this lets redundant interconnect usage, it would produce many networks interconnect messages. Previously, I carried out a cyclic cleanup of the ‘gipcd’ related trace/logs. You can purge these huge trace files if your Clusterware is well and has no issues. If required, you can keep the recent history and purge the rest. In addition, see Doc ID 25776294.8.

Oracle Sharding on Oracle Container Engine for Kubernetes (OKE) uses StatefulSet to provide stable, unique network identifiers and stable, persistent storage so you can create and manage your Oracle Sharding replica set natively in OKE with Oracle supported helm and chart templates. In addition, data is stored on persistent volume, so all the data is still there when a pod is recreated.
Related Resources:
Oracle Sharding on Docker GitHub Link: https://lnkd.in/dN2VUSXd
Oracle Sharding on OKE GitHub Link:  https://lnkd.in/du2gfxG6
OCR (Oracle Container Registry) Link: https://lnkd.in/dTebi76i

 

The paper below describes an automated system that generates, selects, verifies, and maintains materialized views in the Oracle RDBMS; it presents a novel technique, called the extended covering subexpression algorithm, for the automated generation of materialized views. An extensive set of experiments is described that demonstrates the feasibility and efficiency of this approach. This system has been fully implemented and will be deployed on the Oracle Autonomous Database on the Cloud.

For more information see https://dl.acm.org/doi/abs/10.14778/3415478.3415533

The following figure illustrates the phases, and the iterative nature, of a machine learning project. The process flow shows that a machine learning project does not stop when a particular solution is deployed. Instead, the results trigger new business questions, which can be used to develop more focused models.

Would you please download and install the one-off patch for your database version and OS for bugs not included in RU yet? If you do not find a patch for your specific version and OS from MOS, please open a Service Request with details on the patch needed. In addition, please include a list of patches already applied (opatch lsinventory -detail) and any other patches you intend to apply.

Some of the Optimizer bug fixes (not all) are controlled by the “_FIX_CONTROL” setting and are DISABLED by default in 19c when installed either through one-off backport or through RUs. Please refer to the corresponding Patch Readme carefully for one-off patches and enable the fixed control to activate the fix.

Example:

SQL> alter system set “_FIX_CONTROL”=”29302565:1”;

Formatted view on V$LOCK that created via $ORACLE_HOME/rdbms/admin/catblock.sql

  • SESSION_ID == SID in V$LOCK
  • LOCK_TYPE, LOCK_ID1, LOCK_ID2 formatted value of TYPE, ID1, ID2 from V$LOCK
  • MODE_HELD and MODE_REQUESTED formatted value of LMODE and REQUEST from V$LOCK
  • LAST_CONVERT == CTIME of V$LOCK
  • BLOCKING_OTHERS formatted value of BLOCK from V$LOCK

Reference:

https://docs.oracle.com/en/database/oracle/oracle-database/19/refrn/DBA_LOCK.html#GUID-B19FF191-AC89-498D-B2C1-2A18F63DC03D

V$TRANSACTION lists the active transactions in the system.

(i) The following columns together point to a transaction. (i.e.) The combination of the following should give a unique transaction id for that database.

XIDUSN – Undo segment number
XIDSLOT – NUMBER Slot number
XIDSQN – NUMBER Sequence number

(ii) The following columns explain the number of undo blocks / undo records used per transaction.
USED_UBLK – Number of undo blocks used
USED_UREC – Number of undo records used

In the case of transaction rollback, the above columns will estimate the number of undo blocks that need to be rolled back.

The number of undo records and undo blocks (USED_UREC and USED_UBLK) decreases while the transaction rolls back. When they reach 0, the transaction disappears from v$transaction.

The following query can be used to monitor the transaction rollback.
SELECT A.SID, A.USERNAME, B.XIDUSN, B.USED_UREC, B.USED_UBLK
FROM V$SESSION A, V$TRANSACTION B
WHERE A.SADDR=B.SES_ADDR;

(iii) The STATUS following column explains the status of a transaction.

ACTIVE – Explains the transaction is active.

Before performing a normal/transactional shutdown, YOU can check this view to understand any ACTIVE transactions.
SELECT XIDUSN, XIDSLT, XIDSEQ , SES_ADDR, STATUS FROM V$TRANSACTION;