Oracle

Where is the ASM SPFILE?

By Franck Pachot . In the previous blog post, to the question "where is the ASM SPFILE" I answered by running 'asmcmd spget'. But this is available only if the ASM instance is started. If you(…)

Learning and troubleshooting: Follow the path

By Franck Pachot . You query a simple table to get its rows. Did you ever ask yourself how oracle knows which blocks to read from disk? Let's question everything and follow the path to dictionary, bootstrapping, spfile,... up to(…)

Extended clusters and asm_preferred_read_failure_groups

By Franck Pachot . When you have 2 sites that are not too far you can build an extended cluster. You have one node on each site. And you can also use ASM normal redundancy to store data on each(…)

DB_FLASHBACK_RETENTION_TARGET may hang your database

By Franck Pachot . DB_FLASHBACK_RETENTION_TARGET is set to keep enough flashback logs to be able to flashback database within the specified retention window. But it's supposed to be a target only, meaning that on space pressure some files can be(…)

SYS password on Oracle Cloud Service managed database

By Franck Pachot . When you create a DBaaS on the Oracle Cloud services you have to provide an administration password in the database configuration form. You do not need a password to connect to the VM. You use SSH(…)

Data Guard as a Service

By Franck Pachot . A 'Data Guard' checkbox is available for a long time on the Oracle Public Cloud Database as a Service, but it's only for a few days that it does something: create a service with an database(…)

Multitenant dictionary: what is stored only in CDB$ROOT?

By Franck Pachot . Multitenant architecture is about dictionary separation. The idea is that all system metadata is stored only in CDB$ROOT so that space and upgrade time are optimized. Is it entirely true? let's count the rows in the(…)

EM13c Gold Agent Image

One of the most interseting new feature in Enterprise Manager 13c is the Gold Agent Image. This new feature will simplify the agent management. The first thing to do is to create a Gold Agent image, from the setup menu(…)

Enterprise Manager 13c and BI Publisher

In Enterprise Manager 12c, if you need to display the database storage, from the report menu you have the following possibilities: From now on, with Enterprise Manager 13c, this possibility does not exist anymore in the report menu,(…)

Adaptive Plan: How much can STATISTICS COLLECTOR buffer?

By Franck Pachot . The 12c adaptive plan prepares two join methods (Hash Join and Nested Loop), actives the one that has the better cost for the estimated cardinality and computes the point of inflection in cardinality estimation where the(…)