A brief discussion on Oracle ASM and some of its advantages over other file systems. Notes: Database centric file system only used for managing database files High performance Requires a certain amount of tuning Not suitable for all applications Current recommendation is to allow ASM handle raid mirroring rather than let hardware handle it Probably …
You can directly upgrade an Oracle database from version 9.2.0.4 or higher, directly to 11g Upgrade Process. Open database in Upgrade mode: startup upgrade Pre-Upgrade information tool: utlu111i.sql Precursor to the upgrade. Generated report on required and recommended changes to make.. Generally increasing tablespace sizes or remove parameters. Upgrade script: …
Oracle Indexes The degree to which indexes help performance depends partly on the selectivity of the data.High selectivity – Few rows match the index valueLow selectivity – like Country name returns many rows from the index If data is selective but the rows are not stored near each other in the table, many blocks may …
If you are having trouble getting your head around the basics of Oracles Architecture, this video does a good job of simplifying things and making it easy to remember by breaking it down and describing it via everyday examples. You can skip to around 2:30 for the real start of the video. Notes; Datafiles – …
Notes: Data appliance Server with preinstalled and pre optimised database Hardware designed to work with the database software specifically Pre configured clustered database server Exalogic is a preconfigured clustered application server Exadata is a pre configured clustered database server There are other products but they are targeted at OLAP specifically (read rather than write) Exadata supports OLTP and OLAP The first …
This is a pretty cheesy presentation but it gets some interesting points about exadata and smart scan over in only 3 minutes. Notes: Exadata offloads work to its storage servers which reduces the data that needs to travel over the network to the database servers. For example, the storage servers filter out rows that are …
This is a great discussion on and around Oracle Exadata by 2 performance tuning experts. Notes: A very relaxed presentation on the ins and outs of Exadata from a performance tuning and optimization perspective.Skip to about 10 mins in to get past the introductions.Exadata isn’t a solution to all performance problems. You can …
It is possible to use operating system commands such as rm on linux to delete RMAN backup files and generally recover from it, however you are far better using built in RMAN commands to do this. $ rman target / NOCATALOG First, check that all backup files are still available. This will show whether files …
Great webinar on Oracle 12c plugable databases. Skip to 8 minutes for the start of the actual presentation.
[embedplusvideo height=”356″ width=”584″ standard=”http://www.youtube.com/v/L_2TfSHotsY?fs=1″ vars=”ytid=L_2TfSHotsY&width=584&height=356&start=&stop=&rs=w&hd=0&autoplay=0&react=1&chapters=¬es=” id=”ep6822″ /] Watch the rest of this series: Part 1 Part 2 Part 4 Notes: Initilisation params for the Buffer cache: db_cache_size db_block_size It is very helpfull if the buffer block size is a multiple of your operating system block size. The Buffer cache is controled with a Least Recently Used …