The "Query with WHERE only" runs faster on three of the Big Eight. This means the following statements are logically the same but won't run at the same speed: Query with WHERE and HAVING: SELECT column1 FROM Table1 WHERE column2 = 5 GROUP BY column1 HAVING column1 > 6 Query with WHERE only: SELECT column1 FROM Table1 WHERE column2 = 5 AND column1 > 6 GROUP BY column1 GAIN: 3/8 Most DBMSs do not merge WHERE and HAVING clauses.
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