Bug: When executing the EqualsExpression after an update it returns wrong results #395
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| // Bug-Note: Using the GenericExpressionValue works fine | ||
| // Bug-Note: Using the EqualsExpression returns wrong results | ||
| // sts2.setPredicate(new GenericExpressionValue<hyrise_int_t, std::equal_to<hyrise_int_t>>(0, 0, 7)); | ||
| sts2.setPredicate(new EqualsExpression<hyrise_int_t>(0, "company_id", 7)); |
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This line (line 71) causes the bug. Replacing it with line 70 would work.
But the class EqualsExpression is still used/available in the predicate builder of the SimpleTableScan.
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The error is caused by the way this expression system works. The EqualsExpression checks equality for valueIds where the GenericExpressionValue checks the actual value. The update (line 46 to 50) inserts data into the delta, not the main storage. But the EqualsExpression uses only on the main dictionary to find the valueId and the GenericExpressionValue looks for all plain values in main and delta. The system is not designed to work properly with values in the delta storage. But there is another expression system coming: hyrise/hyrise#320 To fix this, you could just include a merge in the test case: |
Added a test for this. This test fails in the current state.
I assume for this test to pass the EqualsExpression needs to be fixed.