What are the Performance improvement techniques available in Teradata?
First of all use EXPLAIN plan to see how the query
is performing. Keywords like Product joins, low confidence are measures of poor
performance.
Make Sure, STATS are collected on the columns used
in WHERE Clause and JOIN columns. If STATS are collected , explain plan will
show HIGH CONFIDENCE This tells the optimizer about the number of rows in that
table which will help the optimizer to choose the redistribution/duplication of
smaller tables.
Check the joining columns & WHERE Clause
whether PI, SI or PPI are used.
Check whether proper alias names are used in the
joining conditions.
Split the queries into smaller subsets in case of
poor performance.
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