Oracle Database as our consultants live it every day: installation and patching, upgrades, RMAN backup and recovery, Data Guard, RAC, performance tuning, multitenant, licensing, and engineered systems such as ODA and Exadata.
By Franck Pachot . In-Memory Column Store is amazing. It brings very good performance to full table scans. I’t easy: just ‘flip a switch’ and you accelerate all reporting queries on your table, without thinking about what to index and how. But in this post, I would like to warn you about the consequences when you just flip that switch.…
By Franck Pachot . Before going to the airport to come back in Europe, the las session I assisted at IOUG Collaborate is a panel: Nothing to BLOG About – Think Again Some famous bloggers were there to help, motivate and inspire people that are afraid to blog. The idea is good. The session was good. The panelists have shared ideas,…
By Franck Pachot . This is a very short post about something I though I had already blogged about. I like SQL Monitoring active reports. The are graphical, and still very light. There is only one thing I don’t like about it in 11g and it has been improved in 12c Look at the following. The query has run for…
By Franck Pachot . Yesterday I was a speaker at Collaborate15 and did my presentation about reading an AWR report. That was great. Many people (and not enough seats). Here are some aswers about questions that came later. I did that presentation at DOAG last year in a much bigger room. But because of the bigger room there was no…
By Franck Pachot . Great events like IOUG Collaborate is a good way to meet experts we know through blogs, twitter,etc. Yesterday evening, with nice music in the background, I was talking with Leighton Nelson about cloning PDB databases. Don’t miss his session today if you are in Las Vegas. The big problem with PDB cloning is that the source must…
By Franck Pachot . The RAC Attack – install a RAC in your own laptop – is a great success at Las Vegas. The idea is to help people follow the RAC Attack cookbook which is available at: http://en.wikibooks.org/wiki/RAC_Attack_-_Oracle_Cluster_Database_at_Home/RAC_Attack_12c/Hardware_Requirements It is a complex configuration and there is always problems to troubleshoot: get Virtual Box be able to run a 64-bits…
By Franck Pachot . A frequent question about replication is the overhead in the source, because in a lot of cases the source is production. Dbvisit replicate comes with the possibility to do the minimum on the source: only the FETCHER process is there to read de redo logs and sends it to the MINE process wich can be on…
By Franck Pachot . There are several new features in 12c about Data Guard: cascaded standby, far sync instance. But there are also some architecture changes: new processes and new wait events. Here is an example of an AWR report of a LogXptMode=’SYNC’ DataGuard configuration in 11g – which means that the log_archive_dest is defined with: ‘LGWR SYNC AFFIRM’ That…
By Franck Pachot . You have read all Cary Millsap work about Oracle database performance tuning. You know that there are no silver bullets. Reducing the response time requires a methodical approach in order to analyze the response time with the goal of eliminating all unnecessary work. But I’ll show something completly opposite here. A performance tuning silver bullet. Do…
By Franck Pachot . In a previous post I’ve shown that from 12.1.0.2 when you have an index on trunc(date) you don’t need additional index. If you need the column with full precision, then you can add it to the index on trunc(). A comment from Rainer Stenzel asked if that optimization is available for other functions. And Mohamed Houri…
By Franck Pachot . The Oracle Database Appliance is really interresting for small enterprises. It’s very good hardware for very good price. It’s capacity on demand licensing for Enteprise Edition. But small companies usually go to Standard Edition for cost reasons. Then does it make sense to propose only Enterprise Edition to the small companies that are interrested by ODA?…
By Franck Pachot . Can we shutdown abort a PDB? Let’s try: SQL> show con_id CON_ID —————————— 3SQL> shutdown abort; Pluggable Database closed. But is it really a shutdown abort? The shutdown abort we know in non-CDB – or in a CDB from CDB$ROOT – is used when the instance cannot checkpoint before closing the file. It leaves the files…
