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Remember the last row group and chunk in the delete buffer #134

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Merged
jdatcmd merged 1 commit into from
Jul 25, 2026
Merged

Remember the last row group and chunk in the delete buffer #134

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31 changes: 31 additions & 0 deletions src/columnar_delete_vector.c
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Original file line number Diff line number Diff line change
Expand Up @@ -46,6 +46,15 @@ typedef struct DeleteVectorBuffer
SubTransactionId subid;
List *chunks; /* list of DeleteVectorChunkBuffer* */
List *rowGroupCache; /* cached NativeRowGroupMetadata* for resolution */

/*
* Last lookup results. A delete arrives in row-number order, so the previous
* answer is almost always the right one; without these, each row rescans both
* lists from the head, and the entry it wants is the one most recently
* appended to the tail.
*/
NativeRowGroupMetadata *lastGroup;
DeleteVectorChunkBuffer *lastChunk;
} DeleteVectorBuffer;

static MemoryContext ColumnarDeleteVectorContext = NULL;
Expand Down Expand Up @@ -115,6 +124,8 @@ delete_vector_get_buffer(Relation rel, uint64 storageId)
buf->subid = subid;
buf->chunks = NIL;
buf->rowGroupCache = NIL;
buf->lastChunk = NULL;
buf->lastGroup = NULL;
ColumnarDeleteVectorBuffers = lappend(ColumnarDeleteVectorBuffers, buf);
MemoryContextSwitchTo(oldContext);

Expand All @@ -133,6 +144,11 @@ delete_vector_find_row_group(DeleteVectorBuffer *buf, uint64 rowNumber)
ListCell *lc;
int attempt;

if (buf->lastGroup != NULL &&
rowNumber >= buf->lastGroup->firstRowNumber &&
rowNumber < buf->lastGroup->firstRowNumber + buf->lastGroup->rowCount)
return buf->lastGroup;

for (attempt = 0; attempt < 2; attempt++)
{
foreach(lc, buf->rowGroupCache)
Expand All @@ -141,7 +157,10 @@ delete_vector_find_row_group(DeleteVectorBuffer *buf, uint64 rowNumber)

if (rowNumber >= g->firstRowNumber &&
rowNumber < g->firstRowNumber + g->rowCount)
{
buf->lastGroup = g;
return g;
}
}

if (attempt == 0)
Expand All @@ -151,6 +170,7 @@ delete_vector_find_row_group(DeleteVectorBuffer *buf, uint64 rowNumber)
Snapshot snap = ColumnarCatalogSnapshot(GetActiveSnapshot());

buf->rowGroupCache = ColumnarReadRowGroupList(buf->storageId, snap);
buf->lastGroup = NULL; /* points into the list just replaced */
MemoryContextSwitchTo(oldContext);
}
}
Expand All @@ -170,12 +190,20 @@ delete_vector_get_chunk(DeleteVectorBuffer *buf, uint64 stripeId, int chunkId,
MemoryContext oldContext;
DeleteVectorChunkBuffer *chunk;

chunk = buf->lastChunk;
if (chunk != NULL && chunk->stripeId == stripeId &&
chunk->chunkId == chunkId && chunk->startRowNumber == startRowNumber)
return chunk;

foreach(lc, buf->chunks)
{
chunk = (DeleteVectorChunkBuffer *) lfirst(lc);
if (chunk->stripeId == stripeId && chunk->chunkId == chunkId &&
chunk->startRowNumber == startRowNumber)
{
buf->lastChunk = chunk;
return chunk;
}
}

oldContext = MemoryContextSwitchTo(ColumnarDeleteVectorContext);
Expand All @@ -188,6 +216,7 @@ delete_vector_get_chunk(DeleteVectorBuffer *buf, uint64 stripeId, int chunkId,
chunk->maskLen = (uint32) ((rowCount + 7) / 8);
chunk->mask = palloc0(chunk->maskLen);
buf->chunks = lappend(buf->chunks, chunk);
buf->lastChunk = chunk;
MemoryContextSwitchTo(oldContext);

return chunk;
Expand Down Expand Up @@ -330,6 +359,8 @@ delete_vector_flush_buffer(DeleteVectorBuffer *buf)

buf->chunks = NIL;
buf->rowGroupCache = NIL;
buf->lastChunk = NULL;
buf->lastGroup = NULL;
}

/*
Expand Down