Queries becoming slower after deploying vertica projections.



I was new to vertica and  was given a set of queries to optimize. I generated the deployment file, by running vertica and built the projections. 


However, I see that the queries have become much slower after deploying the projections. I verified the projections table to see, if the generated projections were indeed getting used and it looked to be the case.


I did some profiling and saw that the scan, network send and network receive operators were taking a lot of time. However I was not quite sure as to how to proceed further. Could someone advise here ?


I did have some joins in my query, but the scan, network send and receive operators were taking up more time according to the profiler.


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      Can you run a explain on the query and post it here.  This way we can spot the problem with more ease.



  • Options

    Even better - do an EXPLAIN for each version of the query - one with the original projections and one with the new projections.  It sounds like you still have both projections.  You can refer to them by name in the query, including the _b0 or _b1 suffix.


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    Thanks Sharon and Adrian.


    This was happening because displaying the output was taking too long. When I appended a where clause to the query, results were in line with expectations.


    Sorry for the trouble.



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