thevar1able/ClickHouse
1
0
Fork 0
mirror of https://github.com/ClickHouse/ClickHouse.git synced 2024-11-21 07:01:59 +00:00
Code Issues Packages Projects Releases Wiki Activity

fixed

Browse Source
This commit is contained in:
Nikita Mikhaylov 2020-09-04 17:36:08 +03:00
parent 9fef663caa
commit d718c5af99
3 changed files with 230 additions and 47 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

129
src/Columns/ColumnNullable.cpp
View File

@ -329,73 +329,110 @@ void ColumnNullable::getPermutation(bool reverse, size_t limit, int null_directi
}
}
void ColumnNullable::updatePermutation(bool reverse, size_t limit, int null_direction_hint, IColumn::Permutation & res, EqualRanges & equal_range) const
void ColumnNullable::updatePermutation(bool reverse, size_t limit, int null_direction_hint, IColumn::Permutation & res, EqualRanges & equal_ranges) const
{
if (limit >= equal_range.back().second || limit >= size())
if (limit >= equal_ranges.back().second || limit >= size())
limit = 0;
EqualRanges new_ranges, temp_ranges;
EqualRanges new_ranges;
for (const auto &[first, last] : equal_range)
const auto is_nulls_last = ((null_direction_hint > 0) != reverse);
if (is_nulls_last)
{
bool direction = ((null_direction_hint > 0) != reverse);
/// Shift all NULL values to the end.
size_t read_idx = first;
size_t write_idx = first;
while (read_idx < last && (isNullAt(res[read_idx])^direction))
for (const auto & [first, last] : equal_ranges)
{
++read_idx;
++write_idx;
}
/// Consider a half interval [first, last)
size_t read_idx = first;
size_t write_idx = first;
size_t end_idx = last;
++read_idx;
if (!limit)
limit = end_idx;
else
limit = std::min(end_idx - first + 1, limit);
/// Invariants:
/// write_idx < read_idx
/// write_idx points to NULL
/// read_idx will be incremented to position of next not-NULL
/// there are range of NULLs between write_idx and read_idx - 1,
/// We are moving elements from end to begin of this range,
/// so range will "bubble" towards the end.
/// Relative order of NULL elements could be changed,
/// but relative order of non-NULLs is preserved.
while (read_idx < last && write_idx < last)
{
if (isNullAt(res[read_idx])^direction)
while (read_idx < limit && !isNullAt(res[read_idx]))
{
std::swap(res[read_idx], res[write_idx]);
++read_idx;
++write_idx;
}
++read_idx;
}
if (write_idx - first > 1)
{
if (direction)
temp_ranges.emplace_back(first, write_idx);
else
++read_idx;
/// Invariants:
/// write_idx < read_idx
/// write_idx points to NULL
/// read_idx will be incremented to position of next not-NULL
/// there are range of NULLs between write_idx and read_idx - 1,
/// We are moving elements from end to begin of this range,
/// so range will "bubble" towards the end.
/// Relative order of NULL elements could be changed,
/// but relative order of non-NULLs is preserved.
while (read_idx < end_idx && write_idx < limit)
{
if (!isNullAt(res[read_idx]))
{
std::swap(res[read_idx], res[write_idx]);
++write_idx;
}
++read_idx;
}
/// We have a range [first, write_idx) of non-NULL values
if (first != write_idx)
new_ranges.emplace_back(first, write_idx);
}
if (last - write_idx > 1)
{
if (direction)
/// We have a range [write_idx, list) of NULL values
if (write_idx != last)
new_ranges.emplace_back(write_idx, last);
else
temp_ranges.emplace_back(write_idx, last);
}
}
while (!new_ranges.empty() && limit && limit <= new_ranges.back().first)
new_ranges.pop_back();
else
{
for (const auto & [first, last] : equal_ranges)
{
/// Shift all NULL values to the beginning.
if (!temp_ranges.empty())
getNestedColumn().updatePermutation(reverse, limit, null_direction_hint, res, temp_ranges);
ssize_t read_idx = last - 1;
ssize_t write_idx = last - 1;
ssize_t begin_idx = first;
equal_range.resize(temp_ranges.size() + new_ranges.size());
std::merge(temp_ranges.begin(), temp_ranges.end(), new_ranges.begin(), new_ranges.end(), equal_range.begin());
while (read_idx >= begin_idx && !isNullAt(res[read_idx]))
{
--read_idx;
--write_idx;
}
--read_idx;
while (read_idx >= begin_idx && write_idx >= begin_idx)
{
if (!isNullAt(res[read_idx]))
{
std::swap(res[read_idx], res[write_idx]);
--write_idx;
}
--read_idx;
}
/// We have a range [write_idx+1, last) of non-NULL values
if (write_idx != static_cast<ssize_t>(last))
new_ranges.emplace_back(write_idx + 1, last);
/// We have a range [first, write_idx+1) of NULL values
if (static_cast<ssize_t>(first) != write_idx)
new_ranges.emplace_back(first, write_idx + 1);
}
}
getNestedColumn().updatePermutation(reverse, 0, null_direction_hint, res, new_ranges);
equal_ranges = std::move(new_ranges);
}
void ColumnNullable::gather(ColumnGathererStream & gatherer)

76
tests/queries/0_stateless/01457_order_by_nulls_first.reference
View File

@ -0,0 +1,76 @@
\N 0
\N 0
\N 0
\N 0
--- DESC NULLS FIRST, ASC
\N 0
\N 0
\N 0
\N 0
\N 0
\N 1
28 0
0 0
--- DESC NULLS LAST, ASC
28 0
0 0
\N 0
\N 0
\N 0
\N 0
\N 0
\N 1
--- ASC NULLS FIRST, ASC
\N 0
\N 0
\N 0
\N 0
\N 0
\N 1
0 0
28 0
--- ASC NULLS LAST, ASC
0 0
28 0
\N 0
\N 0
\N 0
\N 0
\N 0
\N 1
--- DESC NULLS FIRST, DESC
\N 1
\N 0
\N 0
\N 0
\N 0
\N 0
28 0
0 0
--- DESC NULLS LAST, DESC
28 0
0 0
\N 1
\N 0
\N 0
\N 0
\N 0
\N 0
--- ASC NULLS FIRST, DESC
\N 1
\N 0
\N 0
\N 0
\N 0
\N 0
0 0
28 0
--- ASC NULLS LAST, DESC
0 0
28 0
\N 1
\N 0
\N 0
\N 0
\N 0
\N 0

72
tests/queries/0_stateless/01457_order_by_nulls_first.sql
View File

@ -13,7 +13,7 @@ FROM order_by_nulls_first
order by diff desc NULLS FIRST, traf
limit 1, 4;
select '---';
select '--- DESC NULLS FIRST, ASC';
SELECT
diff,
@ -23,4 +23,74 @@ ORDER BY
diff DESC NULLS FIRST,
traf ASC;
select '--- DESC NULLS LAST, ASC';
SELECT
diff,
traf
FROM order_by_nulls_first
ORDER BY
diff DESC NULLS LAST,
traf ASC;
select '--- ASC NULLS FIRST, ASC';
SELECT
diff,
traf
FROM order_by_nulls_first
ORDER BY
diff ASC NULLS FIRST,
traf ASC;
select '--- ASC NULLS LAST, ASC';
SELECT
diff,
traf
FROM order_by_nulls_first
ORDER BY
diff ASC NULLS LAST,
traf ASC;
select '--- DESC NULLS FIRST, DESC';
SELECT
diff,
traf
FROM order_by_nulls_first
ORDER BY
diff DESC NULLS FIRST,
traf DESC;
select '--- DESC NULLS LAST, DESC';
SELECT
diff,
traf
FROM order_by_nulls_first
ORDER BY
diff DESC NULLS LAST,
traf DESC;
select '--- ASC NULLS FIRST, DESC';
SELECT
diff,
traf
FROM order_by_nulls_first
ORDER BY
diff ASC NULLS FIRST,
traf DESC;
select '--- ASC NULLS LAST, DESC';
SELECT
diff,
traf
FROM order_by_nulls_first
ORDER BY
diff ASC NULLS LAST,
traf DESC;
drop table if exists order_by_nulls_first;