Category Archives: Uncategorized

ACFS 12.2 Quirks with defragmentation

I have a 12.2 RAC cluster in my lab, on two virtual machines. Checking out what acfsutil can do, I figured out that it can supposedly do defragmentation: [grid@rac1 ~]$ acfsutil defrag -help Usage: acfsutil [-h] command … # (Version … Continue reading

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RAC 12.2, part 2

Well, today was an interesting day. My ASM, configured with so much effort, stopped working: root@rac1 grid]# . ~grid/.bashrc [root@rac1 grid]# crsctl start ohasd CRS-4640: Oracle High Availability Services is already active CRS-4000: Command Start failed, or completed with errors. … Continue reading

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RAC 12.2

I am in the process of installing RAC 12.2. The installation procedure has undergone a significant change, for the better. It’s now much easier to install it. However, memory and disk requirements have skyrocketed. I needed to allocate 10GB of … Continue reading

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Rename Pluggable Database

I stumbled upon a convenient way to rename a pluggable database: SQL> alter system enable restricted session; System altered. SQL> alter database rename global_name to test12.home.com; Database altered. SQL> alter session set container=cdb$root; Session altered. SQL> select name from v$pdbs; … Continue reading

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12c: OPTIMIZER_DYNAMIC_SAMPLING=11

Oracle 12c has a new feature related to optimizer dynamic sampling. The new level 11 is supposed to put the dynamic sampling on auto pilot and make the statistics available to other users. However, as soon as this was set, … Continue reading

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Smarter DG Broker in Oracle 12c

In Oracle 11G, DG Broker needed to be told whether the standby database was physical or logical. The command to add database in 11G was something like this: ADD DATABASE <DB Unique Name> AS CONNECT IDENTIFIER is <TNS Descriptor> MAINTAINED … Continue reading

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Synthetic Full Backup for Oracle

Synthetic full backup is a method for combining incremental backup into a full backup. It is not a new thing, many backup utilities can do that with file system backups. It is also well described: http://www.techworld.com/storage/what-are-synthetic-backups-1149/ http://www.webopedia.com/TERM/S/synthetic_backup.html However, there is … Continue reading

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