Infrastructure at your Service
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 [[email protected] ~]$ asmcmd lsdg DATAC1 State Type Rebal Sector Logical_Sector Block AU Total_MB Free_MB Req_mir_free_MB Usable_file_MB Offline_disks Voting_files…
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. It is totally valid to consider a move to Open Source databases, but doing it…
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…
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 worth the price, which according to the public price list is USD 47,500 + 17,500…
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 the name of all your PDB snapshots. We have the possibility to create automatic snapshots…
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 a lot. But the technology behind DSS/DWH has improved. Now, with In-Memory Column Store, Smart…
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 in 12.2 where MRP reads the files without the need to have the PDB opened….
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 CDC part in the Oracle Database as Streams is going to be desupported) or Dbvisit…
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 ——- ——— ———— —— ——— ADMIN ALTER SESSION YES NO NO ADMIN ALTER SYSTEM YES NO…
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: [email protected]:/u00/app/oracle/ [DB18] rman target sys/[email protected] Recovery Manager: Release 18.0.0.0.0 – Production on Tue May 15…
