[CALCITE-3070] Inner join between MySQL tables produce wrong results if join order changed

• Type: Bug
• Status: Open
• Priority: Critical
• Resolution: Unresolved
• Affects Version/s: 1.19.0
• Component/s: core, jdbc-adapter
• Assignee: Unassigned
• Reporter: Zhibin Zhou
• Created: 15/May/19 18:24
• Updated: 28/Feb/24 06:03

Description

Summary of issue:

• We are trying to inner join 2 MySQL tables.  
  • persons table: a very small table 
  • foodmart table: a large table
• The query produce different results if we change the join order in the "from" clause: "from A join B" vs "from B join A". One query produces correct results while the other query produces empty results. 
• The physical plan generated for the produce-empty query was not optimal. it tried to scan be big table. 

 

Working query and physical plan:

select "t2"."product_name", "t2"."customer_id" from 
"foodmart-mysql"."foodmart" as "t2" join "persons"."persons" as "t1" 
  on"t1"."person_id_int"="t2"."customer_id" and"t2"."timestamp" >= '1997-02-12 00:00:00' and "t2"."timestamp" < '1997-02-12 00:01:00'

EnumerableCalc(expr#0..4=[\{inputs}], proj#0..1=[\{exprs}]): rowcount = 375.0, cumulative cost = {1287.971895621705 rows, 3719.5 cpu, 0.0 io}, id = 671
  EnumerableJoin(condition=[=($1, $4)], joinType=[inner]): rowcount = 375.0, cumulative cost = {912.971895621705 rows, 1094.5 cpu, 0.0 io}, id = 667
    JdbcToEnumerableConverter: rowcount = 25.0, cumulative cost = {147.5 rows, 283.5 cpu, 0.0 io}, id = 660
      JdbcProject(product_name=[$5], customer_id=[$22], $f85=[>=($78, 1997-02-12 00:00:00)], $f86=[<($78, 1997-02-12 00:01:00)]): rowcount = 25.0, cumulative cost = {145.0 rows, 281.0 cpu, 0.0 io}, id = 658
        JdbcFilter(condition=[AND(>=($78, 1997-02-12 00:00:00), <($78, 1997-02-12 00:01:00))]): rowcount = 25.0, cumulative cost = {125.0 rows, 201.0 cpu, 0.0 io}, id = 656
          JdbcTableScan(table=[[foodmart-mysql, foodmart]]): rowcount = 100.0, cumulative cost = {100.0 rows, 101.0 cpu, 0.0 io}, id = 340
    EnumerableCalc(expr#0..5=[\{inputs}], person_id_int=[$t5]): rowcount = 100.0, cumulative cost = {210.0 rows, 811.0 cpu, 0.0 io}, id = 673
      JdbcToEnumerableConverter: rowcount = 100.0, cumulative cost = {110.0 rows, 111.0 cpu, 0.0 io}, id = 663
        JdbcTableScan(table=[[persons, persons]]): rowcount = 100.0, cumulative cost = {100.0 rows, 101.0 cpu, 0.0 io}, id = 341

 

Produce-empty query and physical plan:

select "t2"."product_name", "t2"."customer_id" from 
"persons"."persons" as "t1" join "foodmart-mysql"."foodmart" as "t2" 
  on "t1"."person_id_int"="t2"."customer_id" and"t2"."timestamp" >= '1997-02-12 00:00:00' and "t2"."timestamp" < '1997-02-12 00:01:00'

EnumerableCalc(expr#0..4=[\{inputs}], proj#0..1=[\{exprs}]): rowcount = 375.0, cumulative cost = {1255.471895621705 rows, 12427.0 cpu, 0.0 io}, id = 334
  EnumerableJoin(condition=[=($1, $4)], joinType=[inner]): rowcount = 375.0, cumulative cost = {880.471895621705 rows, 9802.0 cpu, 0.0 io}, id = 328
    EnumerableCalc(expr#0..84=[\{inputs}], expr#85=[1997-02-12 00:00:00], expr#86=[>=($t78, $t85)], expr#87=[1997-02-12 00:01:00], expr#88=[<($t78, $t87)], expr#89=[AND($t86, $t88)], product_name=[$t5], customer_id=[$t22], $f85=[$t86], $f86=[$t88], $condition=[$t89]): rowcount = 25.0, cumulative cost = {135.0 rows, 9611.0 cpu, 0.0 io}, id = 338
      JdbcToEnumerableConverter: rowcount = 100.0, cumulative cost = {110.0 rows, 111.0 cpu, 0.0 io}, id = 317
        JdbcTableScan(table=[[foodmart-mysql, foodmart]]): rowcount = 100.0, cumulative cost = {100.0 rows, 101.0 cpu, 0.0 io}, id = 1
    JdbcToEnumerableConverter: rowcount = 100.0, cumulative cost = {190.0 rows, 191.0 cpu, 0.0 io}, id = 326
      JdbcProject(person_id_int=[$5]): rowcount = 100.0, cumulative cost = {180.0 rows, 181.0 cpu, 0.0 io}, id = 324
        JdbcTableScan(table=[[persons, persons]]): rowcount = 100.0, cumulative cost = {100.0 rows, 101.0 cpu, 0.0 io}, id = 0