configuring and Understanding current timestamps /local timestamps

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  [Deleted User]

  May 2013

  H Sam, by any chance have you yet found the following page in our documentation?: https://my.vertica.com/docs/CE/6.0.1/HTML/index.htm#12584.htm In short, Vertica inherits time zone settings from the underlying operating system. There are a few more specifics on that page, including details about how to explicitly set a time zone; but I would recommend that you take a look through your Linux distribution's settings and documentation and make sure that it's configured properly first. For example, the command-line command "date" should print out the correct time and time zone. (Note that Vertica may not pick up OS-level timezone changes until you shut down and re-start the server.)

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  Sam_2

  May 2013

  Thanks Adam - I didn't even know about the online docs - been relying on the PDFs, but the online docs looks cleaner. So i realized where I got confused, **I think**...i had two sessions open. So I guess Session A I may have opened recently and shows the current timestamp. Session B I had opened the session 1hr before and shows the timestamp from there....coincidentally...an hr apart. current_timestamp, now(), localtimestamp - all seem to be indicative of when the session logged in. The only time it changes when I give an explicit commit. At least this is what I see in vsql right now as I putza around. Is this the normal behavior? thanks

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  [Deleted User]

  May 2013

  Hi Sam, yes, it's normal that the timestamp is the current session timestamp. Or, more specifically, it's the current transaction timestamp; if you issue a COMMIT, you should get an updated timestamp. This is for consistency -- if you run a script that executes a bunch of statements that depend on current_timestamp, the value of that timestamp won't drift as the script executes. It also allows Vertica to perform a number of substantial optimizations; if we know that a value is never going to change, we only need to generate it once rather than for every row; and in some cases this simplifies the query and allows our optimizer to perform further optimizations. If you really want the current time, you can use SELECT CLOCK_TIMESTAMP();

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  Sam_2

  May 2013

  Got it and Isee what Vertica is trying to do. I guess I was expecting behavior similar to when a connection opens to a relational DB (mysql, sql server, etc). Thanks for the responses and the link to the documentation. I'll try relying on that instead of the PDFs. btw - the website is much more usable than the old site.

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