logbackup compaction: There is no optimization effect when the workload data changes are not concentrated #59900
Description
Bug Report
Please answer these questions before submitting your issue. Thanks!
1. Minimal reproduce step (Required)
Workload characteristics: a large number of small tables, with sporadic updates
2. What did you expect to see? (Required)
After using log backup compaction, the PiTR time is shorter than before using it.
3. What did you see instead (Required)
After using log backup compaction, the PiTR time is longer than before using it
Before using:
[2025/02/28 06:02:40.164 +00:00] [INFO] [collector.go:77] ["restore log success summary"] [total-take=22m42.6293174s] [source-start-point=456118101615575261] [source-end-point=456136975983575261] [target-end-point=456319617602420738] [source-start="2025-02-19 08:07:55.035 +0000"] [source-end="2025-02-20 04:07:55.035 +0000"] [target-end="2025-02-28 05:39:57.519 +0000"] [total-kv-count=660055326] [skipped-kv-count-by-checkpoint=0] [total-size=261.4GB] [skipped-size-by-checkpoint=0B] [average-speed=191.8MB/s]
After using:
[2025/03/04 03:01:16.073 +00:00] [INFO] [collector.go:77] ["restore log success summary"] [total-take=34m4.712071141s] [source-start-point=456323511375626649] [source-end-point=456342385743626649] [target-end-point=456407183321726978] [source-start="2025-02-28 09:47:31.085 +0000"]
[source-end="2025-03-01 05:47:31.085 +0000"] [target-end="2025-03-04 02:27:14.229 +0000"] [total-kv-count=242577383] [skipped-kv-count-by-checkpoint=0] [total-size=31.62GB] [skipped-size-by-checkpoint=0B] ["average-speed (log)"=15.46MB/s] [restore-sst-kv-count=416309359] [restore-s
st-kv-size=225002337307] ["restore-sst-physical-size (after compression)"=35416437434] [restore-sst-total-take=1m44.679031567s] ["average-speed (sst)"=2.149GB/s]
4. What is your TiDB version? (Required)
TiDB version:
Release Version: v9.0.0-alpha-354-gb500d9e
Edition: Community
Git Commit Hash: b500d9e
Git Branch: HEAD
UTC Build Time: 2025-03-04 02:26:29
GoVersion: go1.23.6
Race Enabled: false
Check Table Before Drop: false
Store: tikv
BR version:
Release Version: v9.0.0-alpha-354-gb500d9e1eb-dirty
Git Commit Hash: b500d9e
Git Branch: master
Go Version: go1.24.0
UTC Build Time: 2025-03-04 08:05:07
Race Enabled: false