๐๐ฎ๐๐ฎ, ๐๐ป๐ฎ๐น๐๐๐ถ๐ฐ๐ & ๐๐. Modern alternative to Snowflake. Cost-effective and simple for massive-scale analytics. https://databend.com
On tables that have undergone a FLASHBACK operation, this assumption is broken:
// Take the prev snapshot as base snapshot to avoid get orphan snapshot.
In this PR, the garbage collection root is determined by starting from the current snapshot and traversing backward to the target time point using the prev relation between snapshots. This approach enhances safety (allowing tables modified by the ALTER ... FLASHBACK operation to be handled correctly) but may require traversing a (much) longer history of the table being purged.
Tests
[ ] Unit Test
[ ] Logic Test
[ ] Benchmark Test
[x] No Test - Explain why
Type of change
[ ] Bug Fix (non-breaking change which fixes an issue)
[ ] New Feature (non-breaking change which adds functionality)
[ ] Breaking Change (fix or feature that could cause existing functionality not to work as expected)
I hereby agree to the terms of the CLA available at: https://docs.databend.com/dev/policies/cla/
Summary
Backport PR #16812
On tables that have undergone a FLASHBACK operation, this assumption is broken:
In this PR, the garbage collection root is determined by starting from the current snapshot and traversing backward to the target time point using the
prevrelation between snapshots. This approach enhances safety (allowing tables modified by theALTER ... FLASHBACKoperation to be handled correctly) but may require traversing a (much) longer history of the table being purged.Tests
Type of change
This change isโ