zenoyang opened a new pull request, #19880:
URL: https://github.com/apache/doris/pull/19880
# Proposed changes
Issue Number: close #xxx
Support CRoaring COW feature to reduce bitmap copying
## Problem summary
In some current scenarios, bitmap column copying occurs, for example,
multiple derived columns are derived from the same bitmap column, or the
build/probe column is copied to the join_block during join. Generally, the copy
performance of bitmap is relatively slow, and the CRoaring CopyOnWrite feature
can reduce copying, thereby improving query performance.
Note: CRoaring-0.4.0 COW is thread-unsafe, so it needs to be patched to make
it thread-safe.
The following is the simplified sql of our production scenario:
```sql
SELECT `t2`.`page`
, `t2`.`entrance`
, `t1`.`partition_date`
, `t1`.`entrance_code`
, BITMAP_UNION_COUNT(CASE WHEN t1.type = 3 THEN t1.device_id END) AS `dau`
FROM `doris_vec_stage`.`tbl1` `t1`
LEFT JOIN `doris_vec_stage`.`tbl2` `t2`
ON `t1`.`first_entrance` = `t2`.`second_join_key`
AND `t1`.`page_id` = `t2`.`first_join_key`
WHERE `t2`.`entrance` IN ('******', '******')
AND `t2`.`page` = '******'
AND `t1`.`partition_date` BETWEEN '2023-02-27' AND '2023-03-19'
GROUP BY 1, 2, 3, 4
```
(The following tests are based on doris 1.1.5)
Before, the query took 112756 ms:
```
ProbePhase:
- ProbeExprCallTime: 1.836ms
- ProbeFindNextTime: 5s934ms
- ProbeRows: 90.048K (90048)
- ProbeTime: 1m52s
- ProbeWhenBuildSideOutputTime: 62.457ms
- ProbeWhenProbeSideOutputTime: 54s431ms
- ProbeWhenSearchHashTableTime: 27.254ms
```
Column copy time: `ProbeWhenProbeSideOutputTime: 54s431ms`
Column clear time is not printed here, the actual value is probably:
(112000-5934-54431) ms = 51653 ms
After (open croaing cow), the query takes 53585 ms:
```
ProbePhase:
- ProbeExprCallTime: 1.331ms
- ProbeFindNextTime: 40s635ms
- ProbeRows: 37.348K (37348)
- ProbeTime: 53s96ms
- ProbeWhenBuildSideOutputTime: 17.399ms
- ProbeWhenProbeSideOutputTime: 6s247ms
- ProbeWhenSearchHashTableTime: 6.700ms
```
Column copy time: `ProbeWhenProbeSideOutputTime: 6s247ms`
Column clear time: (53096-40635-6247) ms = 6214 ms
Describe your changes.
## Checklist(Required)
* [ ] Does it affect the original behavior
* [ ] Has unit tests been added
* [ ] Has document been added or modified
* [x] Does it need to update dependencies
* [x] Is this PR support rollback (If NO, please explain WHY)
## Further comments
If this is a relatively large or complex change, kick off the discussion at
[d...@doris.apache.org](mailto:d...@doris.apache.org) by explaining why you
chose the solution you did and what alternatives you considered, etc...
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