ranged projections aren't superprojections when adding columns?

ftobinftobin Vertica Customer

Are ranged projections not counted as superprojections, even if they have all columns?

The definition of a super-projection:

A projection that includes all columns in an anchor table. Vertica uses superprojections to ensure support for all queries and other DML operations.

I have ranged projections which have all columns on a table, but they don't aren't listed as is_super_projection, and that means when I add a column to the table, the column doesn't get added to the ranged projection unless specifically requested.

Best Answers

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    moshegmosheg Vertica Employee Administrator
    Answer ✓

    Projections that include all columns and rows of the anchor table can be considered superprojections in Vertica.
    Therefore, ranged projections, even if they include all columns, would not be counted as superprojections
    as they do not cover all rows of the table.

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    VValdarVValdar Vertica Employee Employee
    Answer ✓

    Hi Frank,

    Superprojections means the whole table lies within.
    That's why every table needs at least one superprojection, otherwise you would loose data!

    The definition of superprojection was written before the implementation of ranged projections, so I agree this brings a bit of confusion and should be edited.

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