zwy991114 opened a new pull request, #66169:
URL: https://github.com/apache/doris/pull/66169
### What problem does this PR solve?
Issue Number: close #xxx
Related PR: #xxx
Problem Summary:
Doris only supports a single compression codec configured at the table level
(via PROPERTIES("compression"=...)), applied uniformly to every column. In real
workloads, columns have very different data characteristics — highly redundant
text columns (URLs, referers, search phrases) compress far better under a
high-level ZSTD/LZ4HC codec, while numeric/low-cardinality columns gain little
and pay the CPU cost. There was no way to tune the codec per column.
This PR adds per-column generic compression codec support for non-cloud
(OLAP) tables. Users can specify a codec and optional level directly on a
column:
```
CREATE TABLE t (
k INT,
url STRING COMPRESSION 'zstd:19',
tag VARCHAR(64) COMPRESSION 'lz4hc:12'
)
DUPLICATE KEY(k)
DISTRIBUTED BY HASH(k) BUCKETS 1;
```
Compression ratio test on ClickBench hits:
Loaded the ClickBench hits dataset into two tables with identical schema.
One table (baseline) uses the ZSTD level 3 default on every column; the other
overrides five heavy text columns with COMPRESSION 'zstd:19'. After forcing
full compaction on both, per-column sizes were read from
information_schema.column_data_sizes.
| Column | Baseline(zstd:3) | Per-column(zstd:19) | Ratio improvement |
| --- | --- | --- | --- |
| OriginalURL | 5.233 | 6.401 | +22.3% |
| Referer | 3.574 | 4.396 | +23.0% |
| SearchPhrase | 4.015 | 4.970 | +23.8% |
|Title | 4.676 | 5.690 | +21.7% |
| URL| 3.954 | 4.905 | +24.1% |
### Release note
None
### Check List (For Author)
- Test <!-- At least one of them must be included. -->
- [x] Regression test
- [x] Unit Test
- [ ] Manual test (add detailed scripts or steps below)
- [ ] No need to test or manual test. Explain why:
- [ ] This is a refactor/code format and no logic has been changed.
- [ ] Previous test can cover this change.
- [ ] No code files have been changed.
- [ ] Other reason <!-- Add your reason? -->
- Behavior changed:
- [x] No.
- [ ] Yes. <!-- Explain the behavior change -->
- Does this need documentation?
- [ ] No.
- [x] Yes. <!-- Add document PR link here. eg:
https://github.com/apache/doris-website/pull/1214 -->
### Check List (For Reviewer who merge this PR)
- [ ] Confirm the release note
- [ ] Confirm test cases
- [ ] Confirm document
- [ ] Add branch pick label <!-- Add branch pick label that this PR should
merge into -->
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