Oracle

RAC Attack! was another great success at C15LV

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:(…)

Dbvisit replicate REDO_READ_METHOD

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(…)

DataGuard wait events have changed in 12c

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(…)

Oracle tuning silver bullet: add an order by to make your query faster

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(…)

Index on SUBSTR(string,1,n) – do you still need old index?

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(…)

Standard Edition on Oracle Database Appliance

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(…)

12c: shutdown abort a PDB?

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(…)

Index on trunc(date) – do you still need old index?

By Franck Pachot . Sometimes we have to index on ( trunc(date) ) because a SQL statement uses predicate on it instead of giving a range from midnight to midnight. When you do that you probably keep the index(…)

Oracle compression, availability and licensing

By Franck Pachot . Various methods of table compression have been introduced at each release. Some require a specific storage system Some requires specific options. Some are only for static data. And it’s not always very clear for the(…)

Generic query for multicriteria search – part II: BIND_AWARE (Adaptive Cursor Sharing)

By Franck Pachot . In the previous post I explained the performance issue encountered when using a generic query to deal with optional search criteria on multiple columns. The statement was shared by all executions, was marked as(…)