One of the preparation steps when installing an Exadata X10M is to verify that the cabling of the RoCE switches is correctly done. The next step is to upgrade the Cisco switches with the latest firmware. During my intervention for Tradeware at the customer, the first didn’t work as the provided script is not compatible with Python3 and the latter complained about wrong cabling.
Here I show how studied the wrong cabling of the X10M switches and how I use Claude.ai (ChatGPT and other AI tools probably also work) to quickly fix the Python script provided by Oracle.
Oracle just updated the Release Schedule of Current Database Releases (Doc ID 742060.1) and changed the release date of database version 23ai on-premises to next half-year. Lets see how many months and bug fixing that means. 🙂
Update on 20.06.2024 – “Added new release dates for Oracle Autonomous Database – Dedicated Exadata Infrastructure, Autonomous Database on Exadata Cloud@Customer, ODA, Exadata and Linux-x86 64”
Sometimes I ask myself why some bugs are not solved. When looking for DBT-16071 we find a blog post from Frank Pachot from more than 7 years ago. He shows that with Oracle 12.2 you can “create” standby databases directly with dbca. But that the script does only a duplicate for standby and nothing more.
I decided to try with 19.22 to see how the situation evolved. It didn’t.
The first thing I got was a DBT-16051 error:
$ dbca -createDuplicateDB -gdbName anjodb01 -primaryDBConnectionString "anjovm01.local.wsl/anjodb01_s1.local.wsl" -sid anjodb01 -createAsStandby -dbUniqueName anjodb01_s2 -silent
Enter SYS user password:
*****
[FATAL] [DBT-16051] Archive log mode is not enabled in the primary database.
ACTION: Primary database should be configured with archive log mode for creating a duplicate or standby database.
Quick check shows the primary is correctly in archivelog mode. The problem is the Easy Connect string. The string I gave “anjovm1.local.wsl/anjodb1_s1.local.wsl” works well on sqlplus, but not with dbca. There you need to specify the port, also when you are just using the default one:
$ dbca -createDuplicateDB -gdbName anjodb01 -primaryDBConnectionString "anjovm01.local.wsl:1521/anjodb01_s1.local.wsl" -sid anjodb01 -createAsStandby -dbUniqueName anjodb01_s2 -silent
Enter SYS user password:
*****
[WARNING] [DBT-10331] Specified SID Name (anjodb01) may have a potential conflict with an already existing database on the system.
CAUSE: The specified SID Name without the trailing numeric characters ({2}) may have a potential conflict with an already existing database on the system.
ACTION: Specify a different SID Name that does not conflict with existing databases on the system.
Prepare for db operation
22% complete
Listener config step
44% complete
Auxiliary instance creation
67% complete
RMAN duplicate
89% complete
Post duplicate database operations
100% complete
The warning DBT-10331 appears because I’ve a “anjodb02” in the same VM, and this could create a problem, as they share the prefix “anjodb”. I don’t expect on a single instance environment that to be a problem though.
And it starts the new standby in ‘read only’ mode, which requires adequate licenses.
SQL> select name, db_unique_name, database_role, open_mode, dataguard_broker from v$database;
NAME DB_UNIQUE_NAME DATABASE_ROLE OPEN_MODE DATAGUAR
--------- ------------------------------ ---------------- -------------------- --------
ANJODB01 ANJODB02_S2 PHYSICAL STANDBY READ ONLY DISABLED
For the moment, I’ll stay with my set of scripts which do the operations in the right way.
Windows and language settings is a common problem for users outside English speaking countries. The windows language on my laptop is English, but time to time I use another laptop in Portugal with the same Microsoft account as login. This laptop is configured in Portuguese. My work laptop’s keyboard is Swiss, locale also set for Switzerland. Windows just gets confused and shows some applications in English, others in German, others in Portuguese.
Today I was testing SQLcl inside VS Code. I tried the help function and get answers in German, plus with the öäü signs wrong.
So I needed to change it to English. Based on SQLcl documentation it reads a file startup.sql once when it starts. And on VS Code, to know where it is currently running, you just have to run the ‘pwd’ command:
SQL> pwd
C:\Users\migue\
Then, on this path, you can create a startup.sql file and change the prompt, and language. My startup.sql starts by changing the display language, then the SQLcl layout and the prompt:
set feedb off termout off
-- changes the display language
alter session set nls_language=american;
-- Changes SQLcl to have word highlight and statusbar
set highlighting on
set highlighting keyword foreground green
set highlighting identifier background blue
set highlighting string foreground yellow
set highlighting number foreground cyan
set highlighting comment foreground white
set statusbar on
set statusbar add editmode
set statusbar add txn
set statusbar add timing
-- Changes prompt to show the instance and pdb name
DEFINE prompt="SQL"
COLUMN col_prompt NEW_VALUE prompt
SELECT UPPER(USER || '@' || SYS_CONTEXT('userenv', 'instance_name')) ||'.'|| SYS_CONTEXT('userenv', 'con_name') col_prompt FROM dual;
set sqlprompt "&prompt> " ;
set termout on feed on
I’ll use a Oracle Linux 9 VM under Windows WSL2 for installing Zabbix. For the exercise, I’ll configure it with PostgreSQL. The database installation step is missing. So, here are all the steps I’ve done.
This was part of an automation script I wrote, which was started during the VM installation using ansible. It was working fine until not long ago. What might have happened?
I end up opening an SR and searching a bit more, until I found out that the culprit was that in the previous steps there are a ORACLE_PATH variable added to .bash_profile . And recently I changed the login.sql to show the name of DB and PDB where the user is connected to. However I forgot to test for the cases when the database is down, on which it was simply showing:
$ sqlplus / as sysdba
SQL*Plus: Release 19.0.0.0.0 - Production on Wed Apr 24 11:36:32 2024
Version 19.21.0.0.0
Copyright (c) 1982, 2022, Oracle. All rights reserved.
>
for some reason dbca did not like it. Ok, partly was my fault, lack of tests. Solution was to make sure that even with the database down (or without database), the sqlplus shows a meaningful prompt.
In a next blog post I’ll show how to personalize SQL*Plus and SQLcl prompt, which is compatible to dbca.
On a full room in the centre of Zurich, Switzerland, two great events dedicated to ODA, Exadata, ExaCC, Exadata at OCI or Azure, PCA and other derivatives took place on March 20th 2024. In the morning organized and sponsored by Tradeware AG was the 21st Oracle Engineering Systems Community meeting, followed by 11th Swiss Oracle Engineering Systems day, organized by Oracle.
Manfred Drodz from Peakmarks showed the results of his performance benchmarks with the new Exadata X10M and how it improves up to 35% compared with X7. Peakmarks is specialized on benchmarking Oracle workloads, helping to choose the right number of CPUs needed when migrating to a new platform.
In Switzerland, Twint is a relatively new payment platform, meanwhile used by more than 50% from the population at least once a month! Erich Steiger showed us how on Exadata performance dilutes application problems, making them quite difficult to spot. But, after convincing the developers to avoid doing unnecessary queries, finally two application bugs could be found, making the existing Exadata resistant for some more years. Currently Twint is looking for the ExaCC solution and its dynamic scaling to absorb the midday peaks.
Mike Dietrich from Oracle presented the new M5 cross-platform migration script and how it was used for migrating a 200TB database from Solaris Supercluster to Exadata. More information on Mike’s website.
After lunch, Ashish Ray presented the Oracle strategy in terms of Exadata, ExaCC and AI. It presented how Oracle look forward with future ExaScale architecture which might remove the limited amount of VMs in a Exadata with its elastic infrastructure.
Swisscom – a major Swiss infrastructure provider – had Roger Fehr and Roger Staubli presenting their ExaCC strategy and how they are together with two core banking solutions (Avaloq and Finova) doing its certification against the Cloud@Customer solution.
Later in the day Marcus Praetzas from Deutsche Bank showed the converged strategy they follow and how ExaCC and Autonomous DB on Exadata allows them to have Oracle as a main database for almost all types of usage.
As a Recap of this intensive day, it was clear that many Swiss and German customers are happy with the Oracle’s Exadata Cloud@Customer solution and pretend to continue using it in their strategy.
Since a few days I’ve a Oracle Database 19c running on my laptop (4 year old i5 processor with 16GB memory) under the Windows Subsystem for Linux with the latest Oracle Linux 9.3. It is working great for testing functionalities. It survives without problem sleep and restart without first shutting down correctly the database.
While there are no snapshot possibility like with Virtualbox, it is possible to export the running image and re-import later.
Below I describe the main steps to quickly install the system.
I had the pleasure to assist to the first Swiss Oracle User Community conference in Zurich the last two days. Great event the the Oracle offices in the “Circle” at the Zurich Airport. It was opportunity to see some ex-Trivadis colleagues – Ludo, Frank, Dani and meet all the Oracle conference addicts.
The two parallel sessions were creating me every hour a dilemma: which presentation will I miss.
Here some of the highlights I noticed – this are what for me was important or new, certainly I will not cover all the knowledge that was in the air.
Swiss OUC day 1
Dominic Giles (Oracle) gave an overview of 23c new Generative AI features and more:
New datatype VECTOR for AI data models was introduced and delayed the 23c release. It allows to use ML models and calculate distance between vectors using different methods.
AI Assist will soon allow to use natural language to create SQL specific for the data model of “our” database. Will also be available on premises – similar but easier than “Select AI” from Autonomous DB
SQL Developer extension for VS Code allows using DB connections directly on VS Code – already available:
Martin Klier explained well and visually how networks, subnets, routers work and what happens when the way to the destination is cut. Really good reminder.
Øyvind Isene shared his story of being the sole developer of an DB automation API leaving the following messages:
“You don’t have the time to do all the errors again. Learn from other errors.” –> share your errors with others
Use Logger when scripting; Use ORDS for DB automation
Again Martin Klier said that Performance is rarely result of an accident. For this, when doing performance analysis, document every action you do, even if will just show that the problem is/was not there; do not use averages and pay attention to skewness.
Chris Saxon and Jasmin Fluri did a small theater play around SQL version management and explained why they use either use Flyway or Liquidbase (integrated into SQLcl) for that.
Swiss OUC day 2
Chris Saxon on a plenum session did a example based overview of the 23c new features for developers:
new DB_DEVELOPER_ROLE – combination of CONNECT+RESOURCE+some other privs.
create if not exists, drop if exist DDLs to avoid errors on multiple execution (might hide things with create if exists, but different)
No more need of “from dual”
Domain datatype extensions – allow named column types with integrated constraints and defaults used schema wide, with extension to have a display and order specific functions (for instance INTERVAL DAY datatype that displays in minutes)
Annotations for columns/tables/domains – kind of extension of comments in name-value pair format
Multiple insert values in a single command – also helpful to generate data
Group by using column alias
sum/floor/ceil/avg on interval and other datatypes
fuzzy_match function to replace like when looking for similar results (without need of Oracle Text)
json converted to insert
boolean usage everywhere (eg: function returns boolean then possible to do “select … from … where func_name(input)”
SQL_TRANSPILER parameter injects content of function directly in SQL, allowing the optimizer to better improve query (default false)
GRANT … ANY … on Schema
Remind to use NOAUTHENTICATION for owner schema and proxy users instead of share passwords.
Mike Dietrich went on with 23c new features on Data Pump:
New dumpfile format with special functionalities for OCI Object Storage
INCLUDE and EXCLUDE can be combined in the same impdp/expdp
All transportable export/import can run now in parallel
Checksum for dumpfiles
REMAP_TABLESPACE=%:USERS (wildcard usage)
Recommendation to gather SYS+SYSTEM schema stats instead of using “gather_dictionary_stats”
Always install DATAPUMP merge patch. It is not part of an RU because it it not RAC Rolling installable
Neil Chandler shared the story of a bank that wanted to replace end-of-life Exadata with something cheaper. Neil spend some time investigating all resource usage – mainly the CPU from storage servers + saved IO from cell offloading and then calculating costs. Conclusion: if they want to keep the performance, there is no cheaper option by using commodity hardware or open source DB.
Frank Pachot on a tmux terminal session explained that the ‘load’ high values in the ‘top’ command from Linux do not mean the machine is overloaded. Basically my get ways were :
There is in recent kernel the PSI tool, not enabled by default, which can show better weather there is pressure and where this is happening.
Different types of IO – specifically a type of direct io can count for the load avg.
Erik van Roon is a fan of SQLcl and convinced the audience by showing why that is superior to SQL*Plus. Check many of its features here or here or here.
Fernando Simon moved from Exadata to ExaCC and shared his thoughts about the new experience:
ExaCC offers good automation, click type of actions for inexperienced DBAs
ExaCC lacks basic checks like if there is enough space to backup OH before a patch [why it backups OH?, does not do out-of-place?]
No integration of created OH images
CPU scale up works well and is immediate, but scale down has a hard minimum wait time of 2h since last scale up
There is no documented tool that allows create a DB with all parameters (block size, charset, silent mode with password)
Even Zero Downtime Migration tool makes as workaround to create a dummy DB, drop it manually and create manually again using DBCA. DBs created directly with DBCA, will not be seen in the OCI, there is no ‘discovery’ command
No possibility to use DBs with different domain in the name in the same ExaCC without unofficial workarounds
ExaCC makes all admin operations serial which can be slow
Dani Schneider showed the new SQL Analysis Report and how it allows to get hints of bad sql when running explain plan.
On my client infrastructure, for improved performance, we need to make sure each VM is pinning to different physical cores.
We do the changes for the moment using the web interface. However, to read easily what the current status is, I’ve wrote a python script that draws a nice table showing where each VM is running and to which cores its vcpu are pinned.
