Skip to content

Comments

Avoid copy/allocation when read view types from parquet#5877

Merged
alamb merged 2 commits intoapache:masterfrom
XiangpengHao:parquet-view
Jun 13, 2024
Merged

Avoid copy/allocation when read view types from parquet#5877
alamb merged 2 commits intoapache:masterfrom
XiangpengHao:parquet-view

Conversation

@XiangpengHao
Copy link
Contributor

@XiangpengHao XiangpengHao commented Jun 12, 2024

Which issue does this PR close?

Part of #5530.

An alternative implementation (maybe subset) of #5557

Rationale for this change

This change is very simple -- only 8 lines, but gives us many performance improvements (10-80x):

arrow_array_reader/StringViewArray/plain encoded, mandatory, no NULLs
                        time:   [274.71 µs 275.03 µs 275.35 µs]
                        change: [-98.842% -98.837% -98.829%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 5 outliers among 100 measurements (5.00%)
  3 (3.00%) high mild
  2 (2.00%) high severe
arrow_array_reader/StringViewArray/plain encoded, optional, no NULLs
                        time:   [275.04 µs 275.41 µs 275.75 µs]
                        change: [-98.848% -98.843% -98.839%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 27 outliers among 100 measurements (27.00%)
  12 (12.00%) low severe
  6 (6.00%) low mild
  6 (6.00%) high mild
  3 (3.00%) high severe
arrow_array_reader/StringViewArray/plain encoded, optional, half NULLs
                        time:   [319.11 µs 319.48 µs 319.98 µs]
                        change: [-94.940% -94.934% -94.926%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 9 outliers among 100 measurements (9.00%)
  8 (8.00%) high mild
  1 (1.00%) high severe
arrow_array_reader/StringViewArray/dictionary encoded, mandatory, no NULLs
                        time:   [259.89 µs 260.22 µs 260.65 µs]
                        change: [-97.848% -97.846% -97.842%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 8 outliers among 100 measurements (8.00%)
  3 (3.00%) high mild
  5 (5.00%) high severe
arrow_array_reader/StringViewArray/dictionary encoded, optional, no NULLs
                        time:   [267.99 µs 268.26 µs 268.56 µs]
                        change: [-97.762% -97.760% -97.757%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 6 outliers among 100 measurements (6.00%)
  3 (3.00%) high mild
  3 (3.00%) high severe
arrow_array_reader/StringViewArray/dictionary encoded, optional, half NULLs
                        time:   [301.73 µs 302.40 µs 303.20 µs]
                        change: [-90.950% -90.895% -90.852%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 5 outliers among 100 measurements (5.00%)
  4 (4.00%) high mild
  1 (1.00%) high severe

To reproduce:

cd parquet
cargo bench --bench arrow_reader --features="arrow test_common experimental" "arrow_array_reader/StringViewArray"

What changes are included in this PR?

Are there any user-facing changes?

@github-actions github-actions bot added the parquet Changes to the parquet crate label Jun 12, 2024
@ariesdevil
Copy link
Contributor

ariesdevil commented Jun 13, 2024

FYI: We discussed in #5557, using an independent view_buffer to replace offset_buffer, see #5557 (comment) for details.

@XiangpengHao
Copy link
Contributor Author

XiangpengHao commented Jun 13, 2024

FYI: We discussed in #5557, using an independent view_buffer to replace offset_buffer, see #5557 (comment) for details.

The try_append_view was not implemented when the discussion was made. Now that we have the API to directly construct a view without calling append_value -- thus avoiding allocating memory, I think it is simpler with this approach.

ariesdevil
ariesdevil reviewed Jun 13, 2024
View reviewed changes
parquet/src/arrow/buffer/offset_buffer.rs Outdated

if len != 0 {
builder
.try_append_view(0, start.as_usize() as u32, len as u32)
Copy link
Contributor

@ariesdevil ariesdevil Jun 13, 2024

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

0 -> append_block's return offset

alamb
alamb approved these changes Jun 13, 2024
View reviewed changes
Copy link
Contributor

@alamb alamb left a comment •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Thank you @XiangpengHao and @ariesdevil

@ariesdevil ariesdevil mentioned this pull request Jun 13, 2024
Closed
alamb
alamb approved these changes Jun 13, 2024
View reviewed changes
Copy link
Contributor

@alamb alamb left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Looks great to me -- thank you @XiangpengHao

I ran the benchmarks and it looks 💯

++ critcmp master parquet-view
group                                                                          master                                 parquet-view
-----                                                                          ------                                 ------------
arrow_array_reader/StringViewArray/dictionary encoded, mandatory, no NULLs     38.83    21.2±0.04ms        ? ?/sec    1.00    546.7±1.85µs        ? ?/sec
arrow_array_reader/StringViewArray/dictionary encoded, optional, half NULLs    7.61      5.6±0.01ms        ? ?/sec    1.00    736.2±1.89µs        ? ?/sec
arrow_array_reader/StringViewArray/dictionary encoded, optional, no NULLs      38.75    21.2±0.04ms        ? ?/sec    1.00    548.1±1.03µs        ? ?/sec
arrow_array_reader/StringViewArray/plain encoded, mandatory, no NULLs          69.37    42.3±0.06ms        ? ?/sec    1.00    609.7±1.34µs        ? ?/sec
arrow_array_reader/StringViewArray/plain encoded, optional, half NULLs         14.44    11.2±0.03ms        ? ?/sec    1.00    774.7±1.57µs        ? ?/sec
arrow_array_reader/StringViewArray/plain encoded, optional, no NULLs           69.40    42.4±0.06ms        ? ?/sec    1.00    610.4±1.59µs        ? ?/sec

I wonder if we can also use try_append_unchecked and make it even faster?

@alamb
Copy link
Contributor

alamb commented Jun 13, 2024

I wonder if we can also use try_append_unchecked and make it even faster?

I am merging this in to keep things moving -- maybe we can consider using try_append_unchecked as a follow on PR

cc @ariesdevil

@alamb alamb merged commit c6359bf into apache:master Jun 13, 2024
@XiangpengHao XiangpengHao deleted the parquet-view branch June 13, 2024 15:46
@alamb alamb mentioned this pull request Jun 17, 2024
Closed
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Reviewers

@alamb alamb alamb approved these changes

+1 more reviewer

@ariesdevil ariesdevil ariesdevil left review comments

Reviewers whose approvals may not affect merge requirements

Assignees

No one assigned

Labels

parquet Changes to the parquet crate

Projects

None yet

Milestone

No milestone

Development

Successfully merging this pull request may close these issues.

3 participants

@XiangpengHao @ariesdevil @alamb