Welcome back to the series of blogs on cool Viewpoint features. Hopefully by now, you've heard about the Teradata "time travel" feature called rewind. Rewind allows one to easily and seamlessly view portlet data and interactions by going back in time for analysis, comparison, or just general reporting. Rewind, dare I say, is a paradigm shift in systems analysis and management. If interested in learning more specifically about Rewind, start with the Viewpoint Rewind screencast.

This blog though is about a facility of rewind that one may not be aware of, that being the rewind tools menu in the portlet headers. When rewind is not active, this portlet header toolbar offers the options of refresh and pause.

Once rewind is enabled, the toolbar options change as shown below.

So let's look at a couple examples of how these rewind tool options might be used. The first tool option is "Pause" which freezes a portlet at a point in time. So let's say, I wanted to cross compare the exact queries running at midnight for the past two Saturdays. I could bring up a dashboard with two Query Monitor portlets, enable rewind, and go to last Saturday at midnight. At this point, both Query Monitor portlets would represent the same list of queries for this past Saturday at midnight. The next operation would be to "Pause" one of the Query Monitor instances and then utilize rewind to go back to the prior Saturday at midnight. At which time, the second Query Monitor instance would be showing queries from two Saturdays ago. This type of operation might be used to see exactly what was running in a common problem window that had just recently started or trying to isolate what queries were running on a bad Saturday versus what was running on a good Saturday run.

An example for use of the "Unlink from Rewind" could be where one realizes the analysis of issues last evening may take some time to complete so the DBA wants to also monitor the current "real time" status of the Teradata systems. As shown below, the System Health portlet instance unlinked from rewind, monitoring current time has reported a new "real time" system issue with the biggulp system. Notice the visual indicator for the unlinked System Health portlet as it has a red slash through the rewind indicator and is displaying current time not the time shown in the rewind bar.

A couple other things worth noting; First the tools bar for the unlinked portlet will now allow refresh, pause, and "Link to Rewind" options as long as rewind is enabled. The other item worth noting is that the time indicator in the portlet header doesn't necessarily align with the current time or when using rewind, the time indicated in the rewind bar. This is intentional and a subtle but important thing to understand. That time is actually an indicator of when the data being displayed was last pulled from the Teradata system. So the example below shows the Productivity portlet displaying 12:30am instead of the rewind time of 12:38am. The Productivity portlet data is configured to collect in 15 minute increments so this time is confirming the last data pull was at 12:30am. Moving forward with rewind, would have this portlet refresh at 12:45am, the next data collection point in time.

Hope this little bit of information on the portlet tool bar and rewind was worth your time. Thanks for listening. Until next time.