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
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.
One of the new query optimizations in 12c are the null-accepting semi-joins. They make subquery unnesting and a semi-join possible in a situation which led to FILTER operation in older versions. Continue reading