[opt](docs) update nereids doc to reflect the latest changes (#21444)
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@ -66,6 +66,8 @@ Turn on auto fall back to legacy planner
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SET enable_fallback_to_original_planner=true;
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```
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Recommand execute analyze on table before query on it to get the benefits of cbo
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## Known issues and temporarily unsupported features
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### temporarily unsupported features
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@ -73,15 +75,12 @@ SET enable_fallback_to_original_planner=true;
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> If automatic fallback is enabled, it will automatically fall back to the old optimizer execution
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- 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
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- DML: All DML statements such as Insert Into Select, Create Table As Select, Update, Delete, etc.
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- DML: Only support below DML statements: Insert Into Select, Update and Delete
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- Matrialized view with predicates
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- Function alias
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- Java UDF and HDFS UDF
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- High concurrent point query optimize
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- Inverted index
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### known issues
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- Cannot use query cache and partition cache to accelarate query
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- Not support MTMV
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- Not support MV created after version 2.0.0
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- 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;
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SET enable_fallback_to_original_planner=true;
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```
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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
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## 已知问题和暂不支持的功能
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### 暂不支持的功能
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@ -73,15 +75,12 @@ SET enable_fallback_to_original_planner=true;
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> 如果开启了自动回退,则会自动回退到旧优化器执行
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- 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
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- DML:所有的 DML 语句,例如 Insert Into Select,Create Table As Select,Update,Delete 等
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- 函数别名
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- DML:仅支持如下DML:Insert Into Select, Update, Delete
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- 带过滤条件的物化视图
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- 别名函数
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- Java UDF 和 HDFS UDF
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- 高并发点查询优化
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- 倒排索引
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### 已知问题
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- 不支持命中 Query Cache 和 Partition Cache
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- 不支持选中多表物化视图
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- 不支持选中使用 2.0 版本新创建物化视图
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- 部分不支持的子查询用法会产生错误结果而不是报错
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