AO vacuum: CommandCounterIncrement before AppendOptimizedTruncateToEOF#1748
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AO vacuum: CommandCounterIncrement before AppendOptimizedTruncateToEOF#1748yjhjstz wants to merge 1 commit into
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ClearAOCSFileSegInfo/ClearFileSegInfo (called from ao_vacuum_rel_recycle_dead_segments) updates pg_aoseg rows via simple_heap_update, which assigns the current CommandId to the new tuple. AppendOptimizedTruncateToEOF then opens a catalog snapshot via GetCatalogSnapshot, which also uses GetCurrentCommandId. Because both operations share the same CommandId, the just-zeroed rows are invisible to the snapshot (cid >= snapshot->curcid), while the old rows with their original non-zero EOF values remain visible. TruncateAOSegmentFile then sees a 0-byte physical file but a non-zero logical EOF and raises: "file size smaller than logical eof" Advancing the command counter before AppendOptimizedTruncateToEOF ensures the zeroed rows are visible to its catalog snapshot (their cid is now strictly less than the new curcid). Fixes: apache#1746
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ClearAOCSFileSegInfo/ClearFileSegInfo (called from ao_vacuum_rel_recycle_dead_segments) updates pg_aoseg rows via simple_heap_update, which assigns the current CommandId to the new tuple. AppendOptimizedTruncateToEOF then opens a catalog snapshot via GetCatalogSnapshot, which also uses GetCurrentCommandId. Because both operations share the same CommandId, the just-zeroed rows are invisible to the snapshot (cid >= snapshot->curcid), while the old rows with their original non-zero EOF values remain visible. TruncateAOSegmentFile then sees a 0-byte physical file but a non-zero logical EOF and raises:
"file size smaller than logical eof"
Advancing the command counter before AppendOptimizedTruncateToEOF ensures the zeroed rows are visible to its catalog snapshot (their cid is now strictly less than the new curcid).
Fixes: #1746
What does this PR do?
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Breaking Changes
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make installcheckmake -C src/test installcheck-cbdb-parallelImpact
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