Closing Dataguard Transfer and Apply Gaps

In the last week, I had two customers that had some failures with their standby databases and contacted me about closing their DG gaps. Since this kind of problems is common, and since the solutions are fairly easy I thought it worth a post to document this for their and your use.

Before we begin, let’s understand what dataguard gaps are. There are two types of gaps: transport and apply gaps. The transport gaps problem (more...)

Error ORA-14766: Unable To Obtain A Stable Metadata Snapshot

A customer called me up and said that he’s hitting “ORA-14766: Unable To Obtain A Stable Metadata Snapshot” and he’s coming up dry on his google search.
This was the first time I encountered this problem, so I thought I’d investigate and write a few words about it, because the problem seems it might be pretty common and the solution was a bit weird.

The Problem

The customer is using and (more...)

ilOUG meetup: Oracle 12c New Features For Better Performance (slides)

It’s been a while since the Israeli user group (iloug) had a technology meetup (SIG meeting). The last time that happened was over two years ago – and since then, we only had the bigger conferences with guests from all over the world. Yesterday we renewed that long time tradition and held such a meetup.

Although I am not part of the OUG board (and not for the lack of trying, just no elections for (more...)

The Best Non-Important Feature of 12cR2: History Command

So I’ve been using Oracle 12cR2 for a couple of weeks now (getting ready to ilOUG meetup in a few weeks), and I decided to share my favorite non-important feature of the new version: the History command for SQLPlus.

As most of you already know, I’m a huge fan of SQLcl (aka SQL Developer Command Line Interface). I’ve written about it a little, and talked about it in conferences a lot. In the last conference (more...)

Script: Inactive Parallel QC Holding Parallel Processes

Working on a data warehouse system can be quite challenging, as I mentioned in the post from yesterday. One of the things we need to take care of is the amount of parallel processes that are in used at all times. Yesterday I wrote about how to locate downgraded sessions. Today we will look at another aspect – who “steals” parallel processes and what can we do to solve it.

One of the biggest thieves (more...)

Script: Finding Session With Downgraded Parallel Execution

I was working with the data warehouse team at a customer site and at some point we realized that some parallel executions are not getting enough resources (downgraded).

Not getting enough parallel processes in such a complex environment is really bad. That means that since everybody is hogging the CPU, some sessions will not be able to complete inside the night ETL time frame. If that happens – some ETLs will go on into the (more...)