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PREWHERE+FINAL

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Denny Crane 2021-05-23 19:47:29 -03:00 committed by GitHub
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docs/en/sql-reference/statements/select/prewhere.md
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@ -16,6 +16,9 @@ A query may simultaneously specify `PREWHERE` and `WHERE`. In this case, `PREWHE
If the `optimize_move_to_prewhere` setting is set to 0, heuristics to automatically move parts of expressions from `WHERE` to `PREWHERE` are disabled.
!!! note "Attention"
The `PREWHERE` section is executed before` FINAL`, so the results of `FROM FINAL` queries may be skewed when using` PREWHERE` with fields not in the `ORDER BY` section of a table.
## Limitations {#limitations}
`PREWHERE` is only supported by tables from the `*MergeTree` family.