SQL: Resolve attributes recursively for improved subquery support (#69765)#70325
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palesz merged 1 commit intoelastic:7.12from Mar 11, 2021
Merged
SQL: Resolve attributes recursively for improved subquery support (#69765)#70325palesz merged 1 commit intoelastic:7.12from
palesz merged 1 commit intoelastic:7.12from
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…astic#69765) Previously we did not resolve the attributes recursively which meant that if a field or expression was re-aliased multiple times (through multiple levels of subqueries), the aliases were only resolved one level down. This led to failed query translation because `ReferenceAttribute`s were pointing to non-existing attributes during query translation. For example the query ```sql SELECT i AS j FROM ( SELECT int AS i FROM test) ORDER BY j ``` failed during translation because the `OrderBy` resolved the `j` ReferenceAttribute to another `i` ReferenceAttribute that was later removed by an Optimization: ``` OrderBy[[Order[j{r}elastic#4,ASC,LAST]]] ! OrderBy[[Order[i{r}elastic#2,ASC,LAST]]] \_Project[[j]] = \_Project[[j]] \_Project[[i]] ! \_EsRelation[test][date{f}elastic#6, some{f}elastic#7, some.string{f}elastic#8, some.string..] \_EsRelation[test][date{f}elastic#6, some{f}elastic#7, some.string{f}elastic#8, some.string..] ! ``` By resolving the `Attributes` recursively both `j{r}` and `i{r}` will resolve to `test.int{f}` above: ``` OrderBy[[Order[test.int{f}elastic#22,ASC,LAST]]] = OrderBy[[Order[test.int{f}elastic#22,ASC,LAST]]] \_Project[[j]] = \_Project[[j]] \_Project[[i]] ! \_EsRelation[test][date{f}elastic#6, some{f}elastic#7, some.string{f}elastic#8, some.string..] \_EsRelation[test][date{f}elastic#6, some{f}elastic#7, some.string{f}elastic#8, some.string..] ! ``` The scope of recursive resolution depends on how the `AttributeMap` is constructed and populated. Fixes elastic#67237
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Previously we did not resolve the attributes recursively which meant that if a field or expression was re-aliased multiple times (through multiple levels of subqueries), the aliases were only resolved one level down. This led to failed query translation because
ReferenceAttributes were pointing to non-existing attributes during query translation.For example the query
failed during translation because the
OrderByresolved thejReferenceAttribute to anotheriReferenceAttribute that was later removed by an Optimization:By resolving the
Attributesrecursively bothj{r}andi{r}will resolve totest.int{f}above:The scope of recursive resolution depends on how the
AttributeMapis constructed and populated.Fixes #67237