[opt](docs) update nereids doc to reflect the latest changes (#21444)

This commit is contained in:
morrySnow
2023-07-03 18:50:01 +08:00
committed by GitHub
parent f7c724f8a3
commit bb33ad0bde
2 changed files with 9 additions and 11 deletions

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@ -66,6 +66,8 @@ Turn on auto fall back to legacy planner
SET enable_fallback_to_original_planner=true;
```
Recommand execute analyze on table before query on it to get the benefits of cbo
## Known issues and temporarily unsupported features
### temporarily unsupported features
@ -73,15 +75,12 @@ SET enable_fallback_to_original_planner=true;
> If automatic fallback is enabled, it will automatically fall back to the old optimizer execution
- Json、Array、Map and Struct types: The table in the query contains the above types, or the expressions in the query outputs the above types
- DML: All DML statements such as Insert Into Select, Create Table As Select, Update, Delete, etc.
- DML: Only support below DML statements: Insert Into Select, Update and Delete
- Matrialized view with predicates
- Function alias
- Java UDF and HDFS UDF
- High concurrent point query optimize
- Inverted index
### known issues
- Cannot use query cache and partition cache to accelarate query
- Not support MTMV
- Not support MV created after version 2.0.0
- Some unsupported subquery usage will produce an error result instead of an error

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@ -66,6 +66,8 @@ SET enable_nereids_planner=true;
SET enable_fallback_to_original_planner=true;
```
为了能够充分利用新优化器的CBO能力,强烈建议对关注性能查询所以来的表,执行analyze语句,以收集列统计信息
## 已知问题和暂不支持的功能
### 暂不支持的功能
@ -73,15 +75,12 @@ SET enable_fallback_to_original_planner=true;
> 如果开启了自动回退,则会自动回退到旧优化器执行
- Json、Array、Map、Struct 类型:查询的表含有以上类型,或者查询中的函数会输出以上类型
- DML:所有的 DML 语句,例如 Insert Into Select,Create Table As Select,UpdateDelete
- 函数别名
- DML:仅支持如下DML:Insert Into Select, Update, Delete
- 带过滤条件的物化视图
- 别名函数
- Java UDF 和 HDFS UDF
- 高并发点查询优化
- 倒排索引
### 已知问题
- 不支持命中 Query Cache 和 Partition Cache
- 不支持选中多表物化视图
- 不支持选中使用 2.0 版本新创建物化视图
- 部分不支持的子查询用法会产生错误结果而不是报错