By Franck Pachot . AWS has just added the possibility to create your oracle Database as as CDB (Container Database), the “new” architecture of Oracle where an instance can manage multiple databases, adding a new level between the heavy instance and lightweight schema: At the time I’m writing this, I see it only in the “old” console (“original interface”) not…
Introduction In an Oracle database, services have multiple purposes: identifying group of users prior authenticating them enabling/disabling access to a database for particular groups managing preferred nodes on a RAC configuration redirecting users to the primary after a switchover/failover when using Data Guard or Dbvisit Standby redirecting read only connections to Standby database with Active Guard option A customer asked…
By Franck Pachot . This is a demo about Oracle ACFS snapshots, and how to understand the used and free space, as displayed by “df”, when there are modifications in the base parent or the snapshot children. The important concept to understand is that, when you take a snapshot, any modification to the child or parent will [grid@cloud ~]$ asmcmd…
By Franck Pachot . I originally wrote this as a comment on the following post that you may find on internet: https://www.2ndquadrant.com/en/blog/oracle-to-postgresql-reasons-to-migrate/ but my comment was not published (many links in it… I suppose it has been flagged as spam?) so I put it there. You should never take any decision on what you read on the internet without verifying.…
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…
I have installed Oracle 19.6 on an EC2 for our Multitenant Workshop training. And of course, during the workshop we create a lot of PDBs. If you don’t have paid for the Enterprise Edition plus the Multitenant Option you can create at most 3 pluggable database. But with this option you can create up to 252 pluggable databases. Does it…
A new feature with Oracle 18c is the PDB snapshot carousel. As indicated by its name a PDB snapshot is a copy of a PDB at a specific point in time. You have the possibility to create up to eight snapshots, when you reach the maximum number of snapshots, the last snapshot is over written. The snapshot carousel is obviously…
By Franck Pachot . The Oracle database has always distinguished two types of workloads: transactional (OLTP) and datawarehouse (VLDB, DWH, DSS, BI, analytics). There is the same idea in the managed Oracle Cloud with two autonomous database services. To show how this is old, here is how they were defined in the Oracle7 Tuning Book: The definition has not changed…
By Franck Pachot . When you clone a PDB on the primary CDB, you want that the same is automatically done on the standby ones. Unfortunately, for this operation, the CDB must be opened read-only. In 12.1 even the PDB needed to be opened read-only (Ludovico Caldara reported this in his blog). This, as far as I know, was fixed…
By Franck Pachot . With this trend of CQRS architectures where the transactions are streamed to a bunch of heterogenous eventually consistent polyglot-persistence microservices, logical replication and Change Data Capture becomes an important component, already at the architecture design phase. This is good for existing products vendors such as Oracle GoldenGate (which must be licensed even to use only the…
By Franck Pachot . The Autonomous Data Warehouse Cloud service is a PaaS managed service where we have a PDB and an ADMIN user which has most of the system privileges. For example, we have the privilege to change initialization parameters: SQL> select * from dba_sys_privs where grantee=user and privilege like ‘ALTER S%’; GRANTEE PRIVILEGE ADMIN_OPTION COMMON INHERITED ——-…
With Oracle 18c, it is possible to use PDB rman backups created on the source CDB (they are called PREPLUGIN backups) when the PDB has been relocated to a target CDB. In my environment, my original CDB is DB18, with the PDB named pdborig. The target CDB is PSI18. The first step consist in running a rman backup on pdborig:…
