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From decibel <...@git.apache.org>
Subject [GitHub] incubator-madlib pull request: Path: Return results for each match
Date Fri, 25 Mar 2016 01:10:47 GMT
Github user decibel commented on a diff in the pull request:

    https://github.com/apache/incubator-madlib/pull/29#discussion_r57410192
  
    --- Diff: src/ports/postgres/modules/utilities/path.py_in ---
    @@ -108,8 +107,11 @@ def path(schema_madlib, source_table, output_table, partition_expr,
                                 *,
                                 nextval('{seq_gen}') AS {id_col_name},
    --- End diff --
    
    What are you basing that on? I don't believe there's any significant performance benefit
to sequences over row_number() (actually, a quick glance at the code leads me to think sequences
will be slower). On top of that, creating a sequence adds to catalog bloat (not to mention
the cost of creating and then dropping the sequence).


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