I think the syntax of segment compaction should be similar with that of other management on segment. Currently in carbondata, we delete segment using syntax: ``` DELETE FROM TABLE CarbonDatabase.CarbonTable WHERE SEGMENT.ID IN (0,5,8) ``` And ``` DELETE FROM TABLE CarbonDatabase.CarbonTable WHERE SEGMENT.STARTTIME BEFORE '2017-06-01 12:05:06' ```
So, we can imitate the above syntax and get the followings: ``` ALTER TABLE [db_name.]table_name COMPACT 'MINOR/MAJOR' WHERE SEGMENT.ID IN (0,5,8) ``` And ``` ALTER TABLE [db_name.]table_name COMPACT 'MINOR/MAJOR' WHERE SEGMENT.STARTTIME BEFORE '2017-06-01 12:05:06' AND SEGMENT.STARTTIME AFTER '2017-05-01 12:05:06' ``` We can support compact segment by specifying IDs and dates. -----原始邮件----- 发件人:xuchuanyin <xuchuan...@hust.edu.cn> 发送时间:2018-03-12 20:23:20 (星期一) 收件人: "Jin Zhou" <dev@carbondata.apache.org> 抄送: carbondata <dev@carbondata.apache.org> 主题: Re: [Discussion] About syntax of compaction on specified segments what does 1/2/3/4 mean in your example? If it is the segment id, probably compact segments by specifying date range is also needed. FROM MOBILE EMAIL CLIENT 在2018年03月12日 10:31，Jin Zhou 写道： Hi, community: I'm working on PR-1812 ( https://github.com/apache/carbondata/pull/1812 <https://github.com/apache/carbondata/pull/1812> ) which aims to support user specified segments in compaction operation. After previous discussions， I think there are 3 possible ways to implement the function: 1) Extending existing SQL syntax of Major and Minor compaciton: ALTER TABLE tablename compact 'MAJOR' '1, 2, 3, 4'; ALTER TABLE tablename compact 'MINOR' '1, 2, 3, 4'; 2) Adding support for CARBON_INPUT_SEGMENTS property of Major and Minor compaciton: SET carbon.input.segments.dbname.tablename=1,3; ALTER TABLE tablename compact 'MAJOR'; 3) Adding a new compaction type and some associated configs, for example, 'CUSTOM' : ALTER TABLE tablename compact 'CUSTOM' '1, 2, 3, 4' I'm grateful for advice from chenliang,ravipesala and gvramana ,detailed discussion history can be seen on web page: ( https://github.com/apache/carbondata/pull/1812 <https://github.com/apache/carbondata/pull/1812> ) Now I'm a bit confused and really need your suggestion :) -- Sent from: http://apache-carbondata-dev-mailing-list-archive.1130556.n5.nabble.com/
