The change
- adds a test which exposes a problem of a peculiar setup of
tombstones that trigger a mutation fragment stream validation exception
- fixes the problem
Applying tombstones in the order:
range_tombstone_change pos(ck1), after_all_prefixed, tombstone_timestamp=1
range_tombstone_change pos(ck2), before_all_prefixed, tombstone=NONE
range_tombstone_change pos(NONE), after_all_prefixed, tombstone=NONE
Leads to swapping the order of mutations when written and read from
disk via sstable writer. This is caused by conversion of
range_tombstone_change (in memory representation) to range tombstone
marker (on disk representation) and back.
When this mutation stream is written to disk, the range tombstone
markers type is calculated based on the relationship between
range_tombstone_changes. The RTC series as above produces markers
(start, end, start). When the last marker is loaded from disk, it's kind
gets incorrectly loaded as before_all_prefixed instead of
after_all_prefixed. This leads to incorrect order of mutations.
The solution is to skip writing a new range_tombstone_change with empty
tombstone if the last range_tombstone_change already has empty
tombstone. This is redundant information and can be safely removed,
while the logic of encoding RTCs as markers doesn't handle such
redundancy well.
Closes#10643
bc18e97473