http://apache-carbondata-dev-mailing-list-archive.168.s1.nabble.com/jira-Updated-CARBONDATA-4034-Improve-the-time-consuming-of-Horizontal-Compaction-for-update-tp106906.html
> Improve the time-consuming of Horizontal Compaction for update
> --------------------------------------------------------------
>
> Key: CARBONDATA-4034
> URL:
https://issues.apache.org/jira/browse/CARBONDATA-4034> Project: CarbonData
> Issue Type: Bug
> Reporter: Jiayu Shen
> Priority: Minor
> Fix For: 2.1.0
>
> Time Spent: 17h 10m
> Remaining Estimate: 0h
>
> In the update flow, horizontal compaction will be significantly slower when updating with a lot of segments(or a lot of blocks). There is a case whose costing is as shown in the log.
> {code:java}
> 2020-10-10 09:38:10,466 | INFO | [OperationManager-Background-Pool-28] | Horizontal Update Compaction operation started for [ods_oms.oms_wh_outbound_order]
> 2020-10-10 09:50:25,718 | INFO | [OperationManager-Background-Pool-28] | Horizontal Update Compaction operation completed for [ods_oms.oms_wh_outbound_order].
> 2020-10-10 10:15:44,302 | INFO | [OperationManager-Background-Pool-28] | Horizontal Delete Compaction operation started for [ods_oms.oms_wh_outbound_order]
> 2020-10-10 10:15:54,874 | INFO | [OperationManager-Background-Pool-28] | Horizontal Delete Compaction operation completed for [ods_oms.oms_wh_outbound_order].{code}
> In this PR, we optimize the process between second and third row of the log, by optimizing the method _performDeleteDeltaCompaction_ in horizontal compaction flow.
>