[GitHub] [spark] WangGuangxin commented on issue #23942: [SPARK-27033][SQL]Add Optimize rule RewriteArithmeticFiltersOnIntegralColumn

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WangGuangxin commented on issue #23942: [SPARK-27033][SQL]Add Optimize rule RewriteArithmeticFiltersOnIntegralColumn
URL: https://github.com/apache/spark/pull/23942#issuecomment-471254770
 
 
   > How do you handle this behaviour change?
   > 
   > ```
   > // v2.4.0
   > scala> Seq(0, Int.MaxValue).toDF("v").write.saveAsTable("t")
   > scala> sql("select * from t").show
   > +----------+
   > |         v|
   > +----------+
   > |         0|
   > |2147483647|
   > +----------+
   > 
   > scala> sql("select * from t where v + 1 > 0").show
   > +---+
   > |  v|
   > +---+
   > |  0|
   > +---+
   > 
   > // this pr
   > scala> sql("select * from t where v + 1 > 0").show
   > +----------+
   > |         v|
   > +----------+
   > |         0|
   > |2147483647|
   > +----------+
   > ```
   
   This is a bad case I didn't think about it before. I found there are four kinds of cases.
   
   - ` v + 1 > 0`  =>   `v > -1 and v <= Int.MAX - 1`
   -  `v  - 1 > 0`  =>   `v > 1  or  (v < Int.MIN + 1 && v > 0 - 1 + Int.MIN - Int.MAX )`
   -  `v + 1 < 0`  =>   `v < -1  or (v > Int.MAX -1 && v < 0 - 1 + Int.MAX - Int.MIN)`
   -  `v - 1 < 0`   =>   `v < 1 and v >= Int.MIN + 1`
   
   For one inequality, after rewrite, there may need two or three inequalities, which makes expressions much more complex. So I think it doesn't worth to convert inequality. We may only handle `= or !=`  here. What do you think?

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