Database management, Oracle Oracle 12.1.0.2.1 Set to Join Conversion 21.08.2014 by Oracle Team By Franck Pachot . Recently, I described the Partial Join Evaluation transformation that appeared last year in Oracle 12c. I did it as an introduction for another transformation that appeared long time ago in 10.1.0.3 but was not(…)
Database Administration & Monitoring, Oracle Oracle 12.1.0.2: Wait event histograms in μs 04.08.2014 by Oracle Team By Franck Pachot . When an Oracle Database spends a high percentage of its DB time in User I/O, I usually check the wait event histograms in order to see if the storage system is working well. But today,(…)
Database management, Oracle PDB media failure may cause the whole CDB to crash 28.07.2014 by Oracle Team By Franck Pachot . Do you remember last year, when 12c arrived with multitenant, David Hueber warned us about the fact that a single PDB can, under certain conditions, generate a complete system downtime? We are beta testers(…)
Database management, Oracle SQL monitoring 12.1.0.2 shows adaptive plans 25.07.2014 by Oracle Team By Franck Pachot . In a previous post, I have described Adaptive Plans. Even if I prefer to show plans with the SQL Monitor active html format, I had to stick with the dbms_xplan for that because SQL(…)
Database management, Oracle Beyond In-Memory, what’s new in 12.1.0.2 ? 22.07.2014 by Oracle Team By Franck Pachot . It’s just a patchset. The delivery that is there to stabilize a release with all the bug fixes. But it comes with a lot of new features as well. And not only the one that(…)
Database management, Oracle Drilling down V$RECOVERY_AREA_USAGE 18.07.2014 by Oracle Team By Franck Pachot . In a previous post I used X$KCCAGF to get more information about reclaimable archived logs in FRA, because there is a bug in standby (not opened) databases where archivelog deletion policy is ignored. I(…)
Database management, Oracle Oracle EM agent 12c thread leak on RAC 18.07.2014 by Oracle Team By Franck Pachot . In a previous post about nproc limit, I wrote that I had to investigate the nproc limit with the number of threads because my Oracle 12c EM agent was having thousands of threads. This(…)
Database management, Oracle Partial Join Evaluation in Oracle 12c 14.07.2014 by Oracle Team By Franck Pachot . Do you think that it’s better to write semi-join SQL statements with IN(), EXISTS(), or to do a JOIN? Usually, the optimizer will evaluate the cost and do the transformation for you. And in this(…)
Database management, Oracle Oracle Parallel Query: Did you use MapReduce for years without knowing it? 26.06.2014 by Oracle Team By Franck Pachot . I’ve read this morning that MapReduce is dead. The first time I heard about MapReduce was when a software architect proposed to stop writing SQL on Oracle Database and replace it with MapReduce processing.
Operating systems, Oracle Linux: how to monitor the nofile limit 18.06.2014 by Oracle Team By Franck Pachot . In a previous post I explained how to measure the number of processes that are generated when a fork() or clone() call checks the nproc limit. There is another limit in /etc/limits.conf – or(…)