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docs: add implication of para_tables_sort

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slzhou 2024-02-22 09:27:53 +08:00
parent 35aed76539
commit 4c258d7187
2 changed files with 2 additions and 2 deletions
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docs/en/12-taos-sql/06-select.md
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@ -93,7 +93,7 @@ The list of currently supported Hints is as follows:
| NO_BATCH_SCAN | None | Sequential table scan | JOIN statment for stable |
| SORT_FOR_GROUP| None | Use sort for partition, conflict with PARTITION_FIRST | With normal column in partition by list |
| PARTITION_FIRST| None | Use Partition before aggregate, conflict with SORT_FOR_GROUP | With normal column in partition by list |
| PARA_TABLES_SORT| None | When sorting the supertable rows by timestamp, No temporary disk space is used | Sorting the supertable rows by timestamp |
| PARA_TABLES_SORT| None | When sorting the supertable rows by timestamp, No temporary disk space is used. When there are numerous tables, each with long rows, the corresponding algorithm associated with this prompt may consume a substantial amount of memory, potentially leading to an Out Of Memory (OOM) situation. | Sorting the supertable rows by timestamp |
For example:

2
docs/zh/12-taos-sql/06-select.md
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@ -93,7 +93,7 @@ Hints 是用户控制单个语句查询优化的一种手段，当 Hint 不适
| NO_BATCH_SCAN | 无 | 采用顺序读表的方式 | 超级表 JOIN 语句 |
| SORT_FOR_GROUP| 无 | 采用sort方式进行分组, 与PARTITION_FIRST冲突 | partition by 列表有普通列时 |
| PARTITION_FIRST| 无 | 在聚合之前使用PARTITION计算分组, 与SORT_FOR_GROUP冲突 | partition by 列表有普通列时 |
| PARA_TABLES_SORT| 无 | 超级表的数据按时间戳排序时, 不使用临时磁盘空间, 只使用内存 | 超级表的数据按时间戳排序时 |
| PARA_TABLES_SORT| 无 | 超级表的数据按时间戳排序时, 不使用临时磁盘空间, 只使用内存。当子表数量多, 行长比较大时候, 会使用大量内存, 可能发生OOM | 超级表的数据按时间戳排序时 |
举例：
```sql