I just came back from RMOUG Training Days conference. It was my first time in Colorado (and obviously my first RMOUG training day) and it was really great (I wrote
I just came back from RMOUG Training Days conference. It was my first time in Colorado (and obviously my first RMOUG training day) and it was really great (I wrote
In the previous post I talked about the order of predicate execution based on the predicate position and inline view.As promised, in this post I’ll add statistics and see what
In my previous post, I wrote about the parsing operation and what happens first. In the footnote I said that the order doesn’t affect performance, the cost based optimizer doesn’t
During OOW17 a customer ran into a wrong result issue in 11.2.0.4, which is very bad. I diagnosed this and found out that it happens because of bloom filter, so
The LIKE operator is a very useful one. It is used to match strings with partial match while using the underscore (‘_’) as a single character wildcard and the percentage sign
When writing a query with order by, we can use the column position instead of its name. This order by”trick” is easy to use, but should be handled carefully as
The internet is full of information about indexes, and for a reason. Indexes in a database is probably the most important performance related topic. There are so many cases, properties,
In the past few months I had several occasions to use the “rownum” pseudo-column to page a query result set. As we know, a query returns a result set, which