I’m currently presenting at Swiss BI Day in Geneva about Oracle In-Memory option to improve analytic queries. Here are the slides, uploaded to SlideShare.
All posts by Franck Pachot
Next Tuesday in Geneva I’m presenting Oracle In-Memory Column Store to Business Intelligence people at the Swiss BI Day After defining what is an analytic query, I show the different approaches to optimize that in Oracle, IMCS being the latest one. Here are some details about that slide.
At our bi-annual dbiXchange I was talking with Nicolas Jardot about his presentation on Result Cache (don’t forget Jérome witt session about RC at DOAG) where he has shown an unexpected behavior on ‘fetch first n rows queries’. That behavior – if it is not a bug – can also be a good thing when using offset queries.
When you have a query failing in ‘ORA-01555: snapshot too old: rollback segment number … with name … too small’ you have two things to do: Convince the developer that the rollback segment is not too small because the message text comes from old versions Find information about query duration, undo retention and stolen blocks statistics. This is the goal of this post
I can hear a lot of complaints about the instability coming from the adaptive features introduced into the optimizer logic at each releases. Giving more intelligence to the optimizer is very good to improve the response time for generated queries, BI, ad-hoc reporting. But when you have an OLTP that works for years with its static set of queries, then you don’t appreciate the plan instability coming from (in reverse chronological order and not exhaustive):…
You want the amazing features of Oracle SQL and PL/SQL with minimal cost. Your database is too large for Oracle XE edition, but not big enough to require the cost of Enterprise Edition. You accept to do things manually, have maintenance windows. You are ok with a RTO of 5 minutes (time to switchover with Dbvisit standby), RPO of 10 minutes (archive_lag_target=600). Your servers have no more than 2 sockets. So you opted for Standard…
Do you think that online operations are available only on Enterprise Edition? That changed in 12c, there is an operation that is online (without the need for the ONLINE keyword) and available in Standard Edition and a very important feature for performance tuning: invisible indexes.