Hi, I have finished the development of a new feature, aggregation by tags, under the collaboration with @JonWang. I’m looking for someone to help to review theses codes.
https://github.com/apache/iotdb/pull/6661 The main changes are 1. Support the basic function of aggregation query by tags, including a) Aggregation query with single tag. b) Aggregation query with multiple tags. c) Aggregation query with both time window and tags. 2. The added integration test cases for 1 are passed both in standalone and cluster mode. 3. User guides for 1 in both Chinese and English. 4. Some internal interfaces enhancement, such as the ability of schema query with or without tags. As we have already had many advanced aggregation features, such as HAVING expression, expressions in aggregation functions, etc. The feature may need more works to achieve all these goals. The current PR is a little large now, and it’s not wise to put other feature supports in this one. The following NOT SUPPORTED features will be implemented in the future PRs. - `GROUP BY TAGS` with `HAVING` clause. - `GROUP BY TAGS` with `ALIGN BY DEVICE`. - `GROUP BY TAGS` ordered by tag values. - `GROUP BY TAGS` with `LIMIT`, `SLMIT`, `OFFSET`, `SOFFSET`. - Expressions as the parameter of aggregation functions in `GROUP BY TAGS` query. Thanks.
