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Before: Constant conjuncts used to be registered in the analyzer together with non-constant conjuncts. Since constant conjuncts are not bound by any slot or tuple they were incorrectly placed into whatever plan node called init() first and then were incorrectly marked as assigned. For handling queries with a limit 0 we had special code in the BE. After: Since constant conjuncts do not fit well into the existing slot/tuple based assignment logic this patch treats them specially as follows. Constant that do not originate from the ON clause of an outer join are evaluated directly. Depending on which clause the conjunct came from either the entire query block is marked as returning an empty set (HAVING clause) or the block is marked as having an empty select-project-join portion (ON and WHERE clause). In the latter case, aggregations (if any) must still be performed. The plan sub-trees that are guaranteed to return an empty result set are implemented by an EmptySetNode. Constant conjuncts from the ON clause of an outer are assigned to the node implementing the join. Similarly, query blocks with a limit 0 are marked as returning an empty result, and planned as an EmptySetNode. As a side effect, this patch also fixes: IMPALA-89: Make our behavior of INSERT OVERWRITE ... LIMIT 0 consistent with Hive's. The target table is left empty after such an operation. Change-Id: Ia35679ac0b3a9d94edae7f310efc4d934c1bfb0d Reviewed-on: http://gerrit.sjc.cloudera.com:8080/3653 Reviewed-by: Alex Behm <alex.behm@cloudera.com> Tested-by: jenkins Reviewed-on: http://gerrit.sjc.cloudera.com:8080/3800
94 lines
1.6 KiB
Plaintext
94 lines
1.6 KiB
Plaintext
====
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---- QUERY
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# testtbl is empty
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select * from testtbl
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---- TYPES
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bigint, string, int
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---- RESULTS
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====
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---- QUERY
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# month ends at 12
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select int_col from alltypessmall where month > 100
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---- TYPES
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int
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---- RESULTS
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====
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---- QUERY
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# Empty partitioned table test
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select field from emptytable
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---- TYPES
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string
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---- RESULTS
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====
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---- QUERY
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# Constant conjunct.
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select t1.id, t2.id
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from functional.alltypestiny t1
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left outer join functional.alltypes t2
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on t1.id = t2.id
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where false
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---- TYPES
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int, int
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---- RESULTS
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====
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---- QUERY
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# Constant conjunct in query block with an aggregation.
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select count(int_col), avg(double_col), count(*)
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from functional.alltypes
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where null
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---- TYPES
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bigint, double, bigint
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---- RESULTS
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0,NULL,0
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====
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---- QUERY
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# Constant conjunct in inline view.
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select e.id, f.id
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from functional.alltypessmall f
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inner join
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(select t1.id
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from functional.alltypestiny t1
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left outer join functional.alltypes t2
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on t1.id = t2.id
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where 1 + 3 > 10) e
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on e.id = f.id
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---- TYPES
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int, int
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---- RESULTS
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====
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---- QUERY
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# Limit 0
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select t1.id, t2.id
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from functional.alltypestiny t1
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left outer join functional.alltypes t2
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on t1.id = t2.id
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limit 0
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---- TYPES
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int, int
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---- RESULTS
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====
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---- QUERY
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# Limit 0 in query block with an aggregation
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select count(int_col), avg(double_col), count(*)
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from functional.alltypes
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limit 0
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---- TYPES
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bigint, double, bigint
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---- RESULTS
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====
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---- QUERY
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# Limit 0 in inline view
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select e.id, f.id
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from functional.alltypessmall f
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inner join
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(select t1.id
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from functional.alltypestiny t1
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left outer join functional.alltypes t2
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on t1.id = t2.id
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limit 0) e
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on e.id = f.id
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---- TYPES
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int, int
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---- RESULTS
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====
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