Oracle Database as our consultants live it every day: installation and patching, upgrades, RMAN backup and recovery, Data Guard, RAC, performance tuning, multitenant, licensing, and engineered systems such as ODA and Exadata.
Introduction ODA X8-2, in the S, M or HA flavour, is the new database appliance from Oracle. But as a brand new product, you can experience troubles due to the lack of maturity. This time, it concerns database creation that can be extremely slow on these servers if you are using ODA 19.5. Edit (April 2020): actually this bug is…
By Franck Pachot . Microsoft SQL Server has implemented MVCC in 2005, which has been proven to be the best approach for transaction isolation (the I in ACID) in OLTP. But are you sure that writers do not block readers with READ_COMMITTED_SNAPSHOT? I’ll show here that some reads are still blocked by locked rows, contrary to the precursors of MVCC…
By Franck Pachot The Oracle Cloud is not only for Oracle Database. You can create a VM running Oracle Linux with full root access to it, even in the free tier: a free VM that will be always up, never expires, with full ssh connectivity to a sudoer user, where you are able to tunnel any port. Of course, there…
Over 1 million IOPS (@8 KByte) and more than 26 GByte/s (@1MByte): Read more to see all impressive benchmark figures from a server with 14 NVMe drives and read why this is still not the best you could get… End of last year, I have gotten a call from Huawei. They (finally) agreed to provide me a server with their…
Introduction As you may know, Oracle Database 19c is available for new (X8-2) or older Oracle Database Appliances since several weeks. Current version is 19.5. But when you go to the official ODA documentation , it still first proposes version 18.7 not compatible with 19c databases. Here is why. 19c database is the final 12.2 First of all, 19c is…
By Franck Pachot . I love databases and, rather than trying to compare and rank them, I like to understand their difference. Sometimes, you make a mistake and encounter an error. Let’s take the following example: create table DEMO (n int); begin transaction; insert into DEMO values (0); select n “after insert” from DEMO; update DEMO set n=1/n; select n…
Introduction Let’s have a look at how to make Oracle database as simple as it was before. Oracle database is a great piece of software, yes it’s quite expensive, but it’s still the reference and most of the companies can find a configuration that fits their needs according to a budget. Another complain about Oracle is the complexity: nothing is…
By Mouhamadou Diaw One question I was asking is if the standby_file_management parameter is relevant in a Dbvisit environment with Oracle Standard Edition. I did some tests and I show here what I did. We suppose that the Dbvisit is already set and that the replication is fine 1 2 3 4 5 6 7 8 9 10 11 12…
By Mouhamadou Diaw Dbvisit snapshot option is a new feature available starting from version 9.0.06. I have tested this option and in this blog I am describing the tasks I have done. The configuration I am using is following dbvist1 : primary server dbvist 2 : standby server orcl : oracle 19c database We suppose that the dbvisit environment is…
ARRAYSIZE or ROWPREFETCH in sqlplus? What is the difference between the well known sqlplus-setting arraysize and the new sqlplus-12.2.-feature rowprefetch? In Blog https://www.dbi-services.com/blog/oracle-fasttrue-in-sqlplus-some-thoughts-about-rowprefetch/ I showed a case, which helps to reduce the logical IOs when using rowprefetch. Here the definition of arraysize and rowprefetch according the documentation: arraysize: SET System Variable Summary: Sets the number of rows, called a batch,…
During my time as a Consultant working on Tuning Tasks I had the feeling that many people think that there is an Oracle-parameter “FAST=TRUE” to speed up the performance and throughput of the database calls. Unfortunately such a parameter is not available, but since version 12cR2 Oracle provided the option “-F” or “-FAST” for sqlplus, which looks like a “FAST=TRUE”-setting.…
Introduction For years, Oracle used the same mechanism for database versioning. A major version, represented by the first number. And then a release number, 1 for the very first edition, and a mature and reliable release 2 for production databases. Both of them having patchsets (the last number) and regular patchset updates (the date optionally displayed at the end) to…
