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Oracle

Franck Pachot

Oracle 12c – peak detection with MATCH_RECOGNIZE

By | Cloud, Database Administration & Monitoring, Oracle | 2 Comments

By Franck Pachot . This post is part of a series of small examples of recent features. I’m running this in the Oracle 20c preview in the Oracle Cloud. I’ll show a very basic example of “Row Pattern Recognition” (the MATCH_RECOGNIZE clause in a SELECT which is documented as “row pattern matching in native SQL” feature by Oracle”). You may be afraid of those names. Of course, because SQL is a declarative language there is…

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Franck Pachot

Oracle 12c – pre-built join index

By | Cloud, Database Administration & Monitoring, Oracle | No Comments

By Franck Pachot . This post is part of a series of small examples of recent features. I’m running this in the Oracle 20c preview in the Oracle Cloud. I have created a few tables in the previous post with a mini-snowflake scheme: a fact table CASES with the covid-19 cases per country and day. And a dimension hierarchy for the country with COUNTRIES and CONTINENTS tables. This title may look strange for people used…

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Franck Pachot

What is a serverless database?

By | AWS, Cloud, Database Administration & Monitoring, Oracle | No Comments

By Franck Pachot . After reading the https://cloudwars.co/oracle/oracle-deal-8×8-larry-ellison-picks-amazons-pocket-again/ paper, I am writing some thoughts about how a database can be serverless and elastic. Of course, a database needs a server to process its data. Serverless doesn’t mean that there are no servers. Serverless as not waiting for server provisioning The first idea of “serverless” is about provisioning. In the past when a developer required a new database to start a new project she had to…

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Clemens Bleile

DB-Upgrade hangs in SE2 waiting on Streams AQ while gathering statistics on LOGMNR-Tables

By | Oracle | No Comments

A couple of weeks ago I upgraded an Oracle Standard Edition 2 test database from 12.1.0.2 to 12.2.0.1 (with the April 2020 Patch Bundle) on Windows. Recently I upgraded the production database. Both upgrades were done with the Database Upgrade Assistant DBUA. I didn’t use AUTOUPGRADE because I had to upgrade only 1 database and the DBUA handles everything for me (including changing the necessary Windows services and update the timezone file). Both upgrades did…

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Franck Pachot

Oracle 18c – select from a flat file

By | Cloud, Database Administration & Monitoring, Oracle | No Comments

By Franck Pachot . This post is the first one from a series of small examples on recent Oracle features. My goal is to present them to people outside of Oracle and relational databases usage, maybe some NoSQL players. And this is why the title is “select from a flat-file” rather than “Inline External Tables”. In my opinion, the names of the features of Oracle Database are invented by the architects and developers, sometimes renamed…

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Clemens Bleile

Functions in SQL with the Multitenant Containers Clause

By | Oracle | No Comments

By Clemens Bleile To prepare a presentation about Multitenant Tuning I wanted to see the METHOD_OPT dbms_stats global preference of all my pluggable DBs. In this specific case I had 3 PBDs called pdb1, pdb2 and pdb3 in my CDB. For testing purposes I changed the global preference in pdb1 from its default ‘FOR ALL COLUMNS SIZE AUTO’ to ‘FOR ALL INDEXED COLUMNS SIZE AUTO’: c##[email protected]@PDB1> exec dbms_stats.set_global_prefs(‘METHOD_OPT’,’FOR ALL INDEXED COLUMNS SIZE AUTO’); c##[email protected]@PDB1> select…

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Mouhamadou Diaw

Oracle 20c : Create a Far Sync Instance Is Now Easy

By | Database Administration & Monitoring, Oracle | No Comments

A far sync instance is like a standby instance as it can receive redo from the primary database and can ship that redo to other members of the Data Guard configuration. But unlike a physical standby instance, a far sync instance does not contain any datafiles and then can not be open for access. A far sync instance just manages a controlfile. A far sync instance cannot be converted to a primary instance or any…

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Mouhamadou Diaw

Patching Oracle Database Appliance From 18.8 to 19.6

By | Database Administration & Monitoring, Operation systems, Oracle | 2 Comments

The ODA software 19.6 is released and people are starting to patch. A direct patch to version 19.6 is possible from version 18.8. Before patching your deployment to Oracle Database Appliance release 19.6, you must upgrade the operating system to Oracle Linux 7. In this blog I am describing the steps I follow when patching an ODA from 18.8 to 19.6. I am using an ODA X7-2 (one node) The first step is of course…

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Marc Wagner

Applying archive log on a standby is failing with error ORA-00756: recovery detected a lost write of a data block

By | Database Administration & Monitoring, Database management, Oracle | No Comments

During one last ODA project, I was deploying dbvisit software version 9.0.10 on Oracle database SE Edition version 18.7. From time to time I was getting lost write of a data block with type KTU UNDO on the standby. Through this blog, I would like to share my investigation and experience on this subject.

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