What EXPLAIN does in Teradata, what is High confidence, Low
confidence and No confidence.. And How we improve the query
performance .
Answer Posted / adi
explain gives the execution strategy means what are the
different steps that the query will go through.
HIGH CONFIDENCE:Statistics are collected.
LOW CONFIDENCE:Statistics are not collected. But the where
condition is having the condition on indexed column. Then
estimations can be based on sampling.
NO CONFIDENCE:Statistics are not collected and the
condition is on non indexec column.
| Is This Answer Correct ? | 18 Yes | 3 No |
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