nextdreamblue commented on code in PR #17146:
URL: https://github.com/apache/doris/pull/17146#discussion_r1118368755
##########
be/src/olap/rowset/segment_v2/segment_iterator.cpp:
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@@ -379,7 +379,15 @@ Status
SegmentIterator::_get_row_ranges_from_conditions(RowRanges* condition_row
DCHECK(_opts.col_id_to_predicates.count(cid) > 0);
RETURN_IF_ERROR(_column_iterators[_schema.unique_id(cid)]->get_row_ranges_by_zone_map(
_opts.col_id_to_predicates[cid].get(),
- _opts.col_id_to_del_predicates.count(cid) > 0
+ // 理论上，如果是两次独立的删除，比如delete from table where a=1; delete from
table where a=2;其实这个地方应该可以使用的;
+ // 但是目前的代码，是把所有不同版本的delete predicates和不同列的delete
predicates都放到一起了，失去了版本信息、失去了谓词间可能是and的关系，
+ // 统一弱化成了delete predicates都是独立的，有一个delete
predicates满足条件，就把page都去掉。
+ // 这个pr的修改方式，就是在当前代码的基础上，当只有一个delete
predicate的时候才能保证后续淘汰page的正确性，所以这里一律加了 == 1的判断才传递delete predicates。
+ // 如果要把不同版本的delete predicates和不同列的delete
predicates作为完整和严谨的逻辑去判断page，需要修改的设计就有点多了，
+ // 目前的方案算是一种优先解决bug的思路，后续可以进一步把delete
predicates这块加速zone判断进行page淘汰的逻辑完善，提高delete predicates使用的场景。
Review Comment:
> Please compact the comment and in English. For example:
>
> ```
> Currently, one transaction can only support one delete condition for page
filtering.
> Following case is allowed:
> delete from table1 where a=1;
> delete from table1 where a=2;
> Following case is not allowed, because one transaction has more than on
delete condition:
> delete from table1 where a=1 and b = 2;
> This may cause bug when you query table1 with a=1;
> You can refer #17145 for more details.
> ```
thanks bro, you are my hero
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