Category Archives: 12c

Custom ILM ADO policy conditions using PL/SQL

In my previous post about ILM storage tiering I wrote about ADO conditions that we can provide for storage tiering policies if moving the segments to a read only tablespace. Another option to make storage tiering “conditional” is to provide a custom condition as pl/sql function returning a boolean. How does it work? Can we use Heat Map information? Continue reading

ILM storage tiering

Being not really new term introduced in 12c, Information Lifecycle Management has been enriched with two new features: Heat Map and ADO (Automatic Data Optimization). The letter allows to define policies on data segments (tables, partitions), which consist of conditions and actions. The conditions are generally being checked based on the information gathered with the Heat Map and defined actions are then taken: compress the data (compression tiering) or move the data (storage tiering). I said “generally”, because, on the one hand, one can define custom conditions (PL/SQL functions) not necessarily using Heat Map and, on the other hand, because of the rather confusing situation using conditions with storage tiering. Continue reading

Merging temporal intervals using MATCH_RECOGNIZE

Some time ago Philipp Salvisberg has posted several thoughts about joining and merging temporal intervals. Recently I was looking for some examples of using the new MATCH_RECOGNIZE clause introduced in 12c and found that these queries can be significantly simplified using the new clause.
Continue reading