Merge pull request #27516 from vdimir/fix-join-const-nullable

Fix Nullable const columns in JOIN
This commit is contained in:
Nikolai Kochetov 2021-08-10 19:56:58 +03:00 committed by GitHub
commit f0a7c6ec94
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4 changed files with 66 additions and 13 deletions

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@ -187,6 +187,7 @@ public:
* So LC(Nullable(T)) would return true, LC(U) -- false. * So LC(Nullable(T)) would return true, LC(U) -- false.
*/ */
bool nestedIsNullable() const { return isColumnNullable(*dictionary.getColumnUnique().getNestedColumn()); } bool nestedIsNullable() const { return isColumnNullable(*dictionary.getColumnUnique().getNestedColumn()); }
bool nestedCanBeInsideNullable() const { return dictionary.getColumnUnique().getNestedColumn()->canBeInsideNullable(); }
void nestedToNullable() { dictionary.getColumnUnique().nestedToNullable(); } void nestedToNullable() { dictionary.getColumnUnique().nestedToNullable(); }
void nestedRemoveNullable() { dictionary.getColumnUnique().nestedRemoveNullable(); } void nestedRemoveNullable() { dictionary.getColumnUnique().nestedRemoveNullable(); }

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@ -2,6 +2,7 @@
#include <Columns/ColumnLowCardinality.h> #include <Columns/ColumnLowCardinality.h>
#include <Columns/ColumnNullable.h> #include <Columns/ColumnNullable.h>
#include <Columns/ColumnConst.h>
#include <DataStreams/materializeBlock.h> #include <DataStreams/materializeBlock.h>
@ -105,25 +106,57 @@ DataTypePtr convertTypeToNullable(const DataTypePtr & type)
return type; return type;
} }
/// Convert column to nullable. If column LowCardinality or Const, convert nested column.
/// Returns nullptr if conversion cannot be performed.
static ColumnPtr tryConvertColumnToNullable(const ColumnPtr & col)
{
if (isColumnNullable(*col) || col->canBeInsideNullable())
return makeNullable(col);
if (col->lowCardinality())
{
auto mut_col = IColumn::mutate(std::move(col));
ColumnLowCardinality * col_lc = assert_cast<ColumnLowCardinality *>(mut_col.get());
if (col_lc->nestedIsNullable())
{
return mut_col;
}
else if (col_lc->nestedCanBeInsideNullable())
{
col_lc->nestedToNullable();
return mut_col;
}
}
else if (const ColumnConst * col_const = checkAndGetColumn<ColumnConst>(*col))
{
const auto & nested = col_const->getDataColumnPtr();
if (nested->isNullable() || nested->canBeInsideNullable())
{
return makeNullable(col);
}
else if (nested->lowCardinality())
{
ColumnPtr nested_nullable = tryConvertColumnToNullable(nested);
if (nested_nullable)
return ColumnConst::create(nested_nullable, col_const->size());
}
}
return nullptr;
}
void convertColumnToNullable(ColumnWithTypeAndName & column) void convertColumnToNullable(ColumnWithTypeAndName & column)
{ {
column.type = convertTypeToNullable(column.type);
if (!column.column) if (!column.column)
{
column.type = convertTypeToNullable(column.type);
return; return;
if (column.column->lowCardinality())
{
/// Convert nested to nullable, not LowCardinality itself
auto mut_col = IColumn::mutate(std::move(column.column));
ColumnLowCardinality * col_as_lc = assert_cast<ColumnLowCardinality *>(mut_col.get());
if (!col_as_lc->nestedIsNullable())
col_as_lc->nestedToNullable();
column.column = std::move(mut_col);
} }
else if (column.column->canBeInsideNullable())
ColumnPtr nullable_column = tryConvertColumnToNullable(column.column);
if (nullable_column)
{ {
column.column = makeNullable(column.column); column.type = convertTypeToNullable(column.type);
column.column = std::move(nullable_column);
} }
} }

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@ -0,0 +1,8 @@
1 2 3 1 3
1 UInt8 2 UInt8 3 Nullable(UInt8)
1 LowCardinality(UInt8) 2 LowCardinality(UInt8) 3 LowCardinality(Nullable(UInt8))
1 LowCardinality(UInt8) 2 LowCardinality(UInt8) 1 LowCardinality(Nullable(UInt8))
1 UInt8 2 UInt8 3 Nullable(UInt8)
1 UInt8 2 UInt8 1 Nullable(UInt8) 3 Nullable(UInt8)
1 LowCardinality(UInt8) 2 LowCardinality(UInt8) 3 LowCardinality(Nullable(UInt8))
1 LowCardinality(UInt8) 2 LowCardinality(UInt8) 1 LowCardinality(Nullable(UInt8)) 3 LowCardinality(Nullable(UInt8))

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@ -0,0 +1,11 @@
SET join_use_nulls = 1;
SELECT *, d.* FROM ( SELECT 1 AS id, 2 AS value ) a SEMI LEFT JOIN ( SELECT 1 AS id, 3 AS values ) AS d USING id;
SELECT id, toTypeName(id), value, toTypeName(value), d.values, toTypeName(d.values) FROM ( SELECT 1 AS id, 2 AS value ) a SEMI LEFT JOIN ( SELECT 1 AS id, 3 AS values ) AS d USING id;
SELECT id, toTypeName(id), value, toTypeName(value), d.values, toTypeName(d.values) FROM ( SELECT toLowCardinality(1) AS id, toLowCardinality(2) AS value ) a SEMI LEFT JOIN ( SELECT toLowCardinality(1) AS id, toLowCardinality(3) AS values ) AS d USING id;
SELECT id, toTypeName(id), value, toTypeName(value), d.id, toTypeName(d.id) FROM ( SELECT toLowCardinality(1) AS id, toLowCardinality(2) AS value ) a SEMI LEFT JOIN ( SELECT toLowCardinality(1) AS id, toLowCardinality(3) AS values ) AS d USING id;
SELECT id, toTypeName(id), value, toTypeName(value), d.values, toTypeName(d.values) FROM ( SELECT 1 AS id, 2 AS value ) a SEMI LEFT JOIN ( SELECT 1 AS id, 3 AS values ) AS d USING id;
SELECT id, toTypeName(id), value, toTypeName(value), d.id, toTypeName(d.id) , d.values, toTypeName(d.values) FROM ( SELECT 1 AS id, 2 AS value ) a SEMI LEFT JOIN ( SELECT 1 AS id, 3 AS values ) AS d USING id;
SELECT id, toTypeName(id), value, toTypeName(value), d.values, toTypeName(d.values) FROM ( SELECT toLowCardinality(1) AS id, toLowCardinality(2) AS value ) a SEMI LEFT JOIN ( SELECT toLowCardinality(1) AS id, toLowCardinality(3) AS values ) AS d USING id;
SELECT id, toTypeName(id), value, toTypeName(value), d.id, toTypeName(d.id) , d.values, toTypeName(d.values) FROM ( SELECT toLowCardinality(1) AS id, toLowCardinality(2) AS value ) a SEMI LEFT JOIN ( SELECT toLowCardinality(1) AS id, toLowCardinality(3) AS values ) AS d USING id;