thevar1able/ClickHouse
1
0
Fork 0
mirror of https://github.com/ClickHouse/ClickHouse.git synced 2024-11-24 08:32:02 +00:00
Code Issues Packages Projects Releases Wiki Activity

dbms: Cleanup [#METR-19266]

Browse Source
This commit is contained in:
Alexey Arno 2016-08-05 12:19:32 +03:00
parent a1218c3134
commit f6ab219176
2 changed files with 25 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
dbms/src/Functions/FunctionsNull.cpp
View File

@ -172,7 +172,7 @@ void FunctionCoalesce::executeImpl(Block & block, const ColumnNumbers & argument
/// For the NULL value. /// For the NULL value.
new_args.push_back(block.columns()); new_args.push_back(block.columns());
/// Append a NULL column to block. /// Append a NULL column.
ColumnWithTypeAndName elem; ColumnWithTypeAndName elem;
elem.column = std::make_shared<ColumnNull>(block.rowsInFirstColumn(), Null()); elem.column = std::make_shared<ColumnNull>(block.rowsInFirstColumn(), Null());
elem.type = std::make_shared<DataTypeNull>(); elem.type = std::make_shared<DataTypeNull>();

33
dbms/src/Functions/IFunction.cpp
View File

@ -8,6 +8,13 @@
namespace DB namespace DB
{ {
/// Except for functions whose method hasSpecialSupportForNulls() returns true,
/// such as multiIf, most of them deal with nullable or null arguments according
/// to the following scheme:
/// - If at least one argument is null, we return null.
/// - If at least one argument is nullable, we run the function on non-nullable
/// columns, then we wrap the result we have obtained into a nullable column.
namespace namespace
{ {
@ -29,6 +36,7 @@ void createNullValuesByteMap(Block & block, size_t result)
} }
} }
/// Check if a block contains at least one null column.
bool hasNullColumns(const Block & block, const ColumnNumbers & arguments) bool hasNullColumns(const Block & block, const ColumnNumbers & arguments)
{ {
for (const auto & arg : arguments) for (const auto & arg : arguments)
@ -40,6 +48,7 @@ bool hasNullColumns(const Block & block, const ColumnNumbers & arguments)
return false; return false;
} }
/// Check if at least one column is null.
bool hasNullColumns(const ColumnsWithTypeAndName & args) bool hasNullColumns(const ColumnsWithTypeAndName & args)
{ {
for (const auto & arg : args) for (const auto & arg : args)
@ -51,7 +60,8 @@ bool hasNullColumns(const ColumnsWithTypeAndName & args)
return false; return false;
} }
bool hasNullColumns(const DataTypes & args) /// Check if at least one argument is null.
bool hasNullArguments(const DataTypes & args)
{ {
for (const auto & arg : args) for (const auto & arg : args)
{ {
@ -62,6 +72,7 @@ bool hasNullColumns(const DataTypes & args)
return false; return false;
} }
/// Check if a block contains at least one nullable column.
bool hasNullableColumns(const Block & block, const ColumnNumbers & arguments) bool hasNullableColumns(const Block & block, const ColumnNumbers & arguments)
{ {
for (const auto & arg : arguments) for (const auto & arg : arguments)
@ -73,6 +84,7 @@ bool hasNullableColumns(const Block & block, const ColumnNumbers & arguments)
return false; return false;
} }
/// Check if at least one column is nullable.
bool hasNullableColumns(const ColumnsWithTypeAndName & args) bool hasNullableColumns(const ColumnsWithTypeAndName & args)
{ {
for (const auto & arg : args) for (const auto & arg : args)
@ -84,7 +96,8 @@ bool hasNullableColumns(const ColumnsWithTypeAndName & args)
return false; return false;
} }
bool hasNullableColumns(const DataTypes & args) /// Check if at least one argument is nullable.
bool hasNullableArguments(const DataTypes & args)
{ {
for (const auto & arg : args) for (const auto & arg : args)
{ {
@ -95,6 +108,7 @@ bool hasNullableColumns(const DataTypes & args)
return false; return false;
} }
/// Turn the specified set of columns into a set of non-nullable columns.
ColumnsWithTypeAndName toNonNullableColumns(const ColumnsWithTypeAndName & args) ColumnsWithTypeAndName toNonNullableColumns(const ColumnsWithTypeAndName & args)
{ {
ColumnsWithTypeAndName new_args; ColumnsWithTypeAndName new_args;
@ -118,7 +132,8 @@ ColumnsWithTypeAndName toNonNullableColumns(const ColumnsWithTypeAndName & args)
return new_args; return new_args;
} }
DataTypes toNonNullableColumns(const DataTypes & args) /// Turn the specified set of data types into a set of non-nullable data types.
DataTypes toNonNullableArguments(const DataTypes & args)
{ {
DataTypes new_args; DataTypes new_args;
new_args.reserve(args.size()); new_args.reserve(args.size());
@ -142,12 +157,12 @@ DataTypes toNonNullableColumns(const DataTypes & args)
DataTypePtr IFunction::getReturnType(const DataTypes & arguments) const DataTypePtr IFunction::getReturnType(const DataTypes & arguments) const
{ {
if (!hasSpecialSupportForNulls() && hasNullColumns(arguments)) if (!hasSpecialSupportForNulls() && hasNullArguments(arguments))
return std::make_shared<DataTypeNull>(); return std::make_shared<DataTypeNull>();
if (!hasSpecialSupportForNulls() && hasNullableColumns(arguments)) if (!hasSpecialSupportForNulls() && hasNullableArguments(arguments))
{ {
const DataTypes new_args = toNonNullableColumns(arguments); const DataTypes new_args = toNonNullableArguments(arguments);
return getReturnTypeImpl(new_args); return getReturnTypeImpl(new_args);
} }
else else
@ -177,12 +192,12 @@ void IFunction::getReturnTypeAndPrerequisites(
void IFunction::getLambdaArgumentTypes(DataTypes & arguments) const void IFunction::getLambdaArgumentTypes(DataTypes & arguments) const
{ {
if (!hasSpecialSupportForNulls() && hasNullColumns(arguments)) if (!hasSpecialSupportForNulls() && hasNullArguments(arguments))
return; return;
if (!hasSpecialSupportForNulls() && hasNullableColumns(arguments)) if (!hasSpecialSupportForNulls() && hasNullableArguments(arguments))
{ {
DataTypes new_args = toNonNullableColumns(arguments); DataTypes new_args = toNonNullableArguments(arguments);
getLambdaArgumentTypesImpl(new_args); getLambdaArgumentTypesImpl(new_args);
arguments = std::move(new_args); arguments = std::move(new_args);
} }