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Testing the just released PostgreSQL 9.5 Alpha in a docker container

On the 2cnd of July the PostgreSQL Global Development Group released an alpha version of the upcoming PostgreSQL 9.5. The same day, Josh Berkus, another of those PostgreSQL core team members released a docker image for(…)

Multitenant vs. schema based consolidation

By Franck Pachot . If you want to install multiple instances of a software, for example you host the ERP for several companies or subsidiaries, you have 3 solutions: have one database and multiple schema have multiple databases have(…)

ODA – VMs possibilities & performances

As you know it is possible to install the ODA in a virtualized mode and to take avantages from all cores not licensed with Enterprise Edition for additional VMs. The question is what could we do with it and(…)

Indexing for like/similarity operations

Indexing queries for like/similarity conditions is not that easy with the usual index types. The only option you have with btree indexes (especially if the wild-card is at the beginning of the filter) is to create a partial(…)

Oracle Log Writer and Write-Ahead-Logging

By Franck Pachot . I posted a tweet with a link to a very old document – 20 years old – about ‘internals of recovery’. It’s a gem. All the complexity of the ACID mecanisms of Oracle are(…)

Oracle Database Cloud Service – My first trial

By Franck Pachot . The cloud has been annouced, I want to try. From the cloud.oracle.com/database website, there is Trial only for the ‘Database Schema Service’ so I asked fot it, received an e-mail with connection info and it(…)

Quickly create a hundred databases and users

Do you need a hundred databases and users for training etc. in PostgreSQL? Just a few lines of code: [postgres8@oel7 data]$ cat create_databases.sh #!/bin/bash NUMOFDBS=100 for i in `seq ${NUMOFDBS}`; do psql -q -c "create user u${i}(…)

RAC buffer states: XCUR, SCUR, PI, CI

By Franck Pachot . In RAC, blocks are copied across instances by the Global Cache Service. In single instance, we have only two status: CR for consistent read clones where undo is applied, and CUR for the current version(…)

another way to list invalid objects

How often did I type a query like this to list the invalid objects in a database? select count(*) from dba_objects where status 'VALID'; -- and user in/not in Today I learned another way to do the same. There(…)

Multithreaded 12c and ‘connect / as sysdba’

By Franck Pachot . In Oracle 12c you can run Oracle processes as operating system threads, lowering the number of OS processes. But you can’t use OS authentification: you need to provide a password. Here is a way to(…)