Infrastructure at your Service
Creating a snapshopt copy Pluggable Database (PDB) on top of Automatic Storage Management (ASM) is not possible, because you need to have a filesystem which supports sparse files. According the following MOS-Note sparse files are supported on Automatic Storage Management Cluster File System (ACFS) since 12.2.: 12.2 Oracle ACFS Sparse Files Enhancements (Doc ID 2200264.1) However, I thought it is more fun to create a PDB Snapshot Copy on a XFS-filesystem, which I wanted to…
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 in “new database creation flow”. It is displayed as a different Edition, however it is…
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 me if services could be used for switching between PDBs without modifying client’s connexion, for…
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….
