Alvaro Herrera wrote:
> Jinyu Zhang wrote:
>
> > Update the patch_brin_optimze_mem according to your comment.
>
> I have added this patch to the commitfest, which I've been intending to
> get in for a long time. I'll be submitting an updated patch soon.
Here it is. I addressed some of Tomas' comments, but not all (so this
is mostly just a rebased on Jinyu's original submission).
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
diff --git a/contrib/pageinspect/brinfuncs.c b/contrib/pageinspect/brinfuncs.c
index 2c7963e..dc9cc2d 100644
--- a/contrib/pageinspect/brinfuncs.c
+++ b/contrib/pageinspect/brinfuncs.c
@@ -226,7 +226,8 @@ brin_page_items(PG_FUNCTION_ARGS)
if (ItemIdIsUsed(itemId))
{
dtup = brin_deform_tuple(bdesc,
-
(BrinTuple *) PageGetItem(page, itemId));
+
(BrinTuple *) PageGetItem(page, itemId),
+ NULL);
attno = 1;
unusedItem = false;
}
diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index b22563b..04c50fe 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -182,7 +182,7 @@ brininsert(Relation idxRel, Datum *values, bool *nulls,
MemoryContextSwitchTo(tupcxt);
}
- dtup = brin_deform_tuple(bdesc, brtup);
+ dtup = brin_deform_tuple(bdesc, brtup, NULL);
/*
* Compare the key values of the new tuple to the stored index
values;
@@ -328,6 +328,9 @@ bringetbitmap(IndexScanDesc scan, TIDBitmap *tbm)
FmgrInfo *consistentFn;
MemoryContext oldcxt;
MemoryContext perRangeCxt;
+ BrinMemTuple *dtup;
+ BrinTuple *btup;
+ uint32 btupInitSize;
opaque = (BrinOpaque *) scan->opaque;
bdesc = opaque->bo_bdesc;
@@ -348,6 +351,13 @@ bringetbitmap(IndexScanDesc scan, TIDBitmap *tbm)
* key reference each of them. We rely on zeroing fn_oid to InvalidOid.
*/
consistentFn = palloc0(sizeof(FmgrInfo) * bdesc->bd_tupdesc->natts);
+ dtup = brin_new_memtuple(bdesc);
+
+ /*
+ * Estimate the approximate size of btup and allocate memory for btup.
+ */
+ btupInitSize = bdesc->bd_tupdesc->natts * 16;
+ btup = palloc(btupInitSize);
/*
* Setup and use a per-range memory context, which is reset every time
we
@@ -379,7 +389,10 @@ bringetbitmap(IndexScanDesc scan, TIDBitmap *tbm)
scan->xs_snapshot);
if (tup)
{
- tup = brin_copy_tuple(tup, size);
+ if(size <= btupInitSize)
+ memcpy(btup, tup, size);
+ else
+ btup = brin_copy_tuple(tup, size);
LockBuffer(buf, BUFFER_LOCK_UNLOCK);
}
@@ -387,15 +400,13 @@ bringetbitmap(IndexScanDesc scan, TIDBitmap *tbm)
* For page ranges with no indexed tuple, we must return the
whole
* range; otherwise, compare it to the scan keys.
*/
- if (tup == NULL)
+ if (btup == NULL)
{
addrange = true;
}
else
{
- BrinMemTuple *dtup;
-
- dtup = brin_deform_tuple(bdesc, tup);
+ dtup = brin_deform_tuple(bdesc, btup, dtup);
if (dtup->bt_placeholder)
{
/*
@@ -1175,7 +1186,7 @@ union_tuples(BrinDesc *bdesc, BrinMemTuple *a, BrinTuple
*b)
"brin union",
ALLOCSET_DEFAULT_SIZES);
oldcxt = MemoryContextSwitchTo(cxt);
- db = brin_deform_tuple(bdesc, b);
+ db = brin_deform_tuple(bdesc, b, NULL);
MemoryContextSwitchTo(oldcxt);
for (keyno = 0; keyno < bdesc->bd_tupdesc->natts; keyno++)
diff --git a/src/backend/access/brin/brin_tuple.c
b/src/backend/access/brin/brin_tuple.c
index ec5fc56..20b0079 100644
--- a/src/backend/access/brin/brin_tuple.c
+++ b/src/backend/access/brin/brin_tuple.c
@@ -348,54 +348,69 @@ BrinMemTuple *
brin_new_memtuple(BrinDesc *brdesc)
{
BrinMemTuple *dtup;
- char *currdatum;
long basesize;
- int i;
basesize = MAXALIGN(sizeof(BrinMemTuple) +
sizeof(BrinValues) *
brdesc->bd_tupdesc->natts);
dtup = palloc0(basesize + sizeof(Datum) * brdesc->bd_totalstored);
- currdatum = (char *) dtup + basesize;
- for (i = 0; i < brdesc->bd_tupdesc->natts; i++)
- {
- dtup->bt_columns[i].bv_attno = i + 1;
- dtup->bt_columns[i].bv_allnulls = true;
- dtup->bt_columns[i].bv_hasnulls = false;
- dtup->bt_columns[i].bv_values = (Datum *) currdatum;
- currdatum += sizeof(Datum) * brdesc->bd_info[i]->oi_nstored;
- }
+
+ dtup->bt_values = palloc(sizeof(Datum) * brdesc->bd_totalstored);
+ dtup->bt_allnulls = palloc(sizeof(bool) * brdesc->bd_tupdesc->natts);
+ dtup->bt_hasnulls = palloc(sizeof(bool) * brdesc->bd_tupdesc->natts);
dtup->bt_context = AllocSetContextCreate(CurrentMemoryContext,
"brin dtuple",
ALLOCSET_DEFAULT_SIZES);
+
+ brin_memtuple_initialize(dtup, brdesc);
+
return dtup;
}
/*
- * Reset a BrinMemTuple to initial state
+ * Reset a BrinMemTuple to initial state. We return the same tuple, for
+ * notational convenience.
*/
-void
+BrinMemTuple *
brin_memtuple_initialize(BrinMemTuple *dtuple, BrinDesc *brdesc)
{
int i;
+ char *currdatum;
MemoryContextReset(dtuple->bt_context);
+
+ currdatum = (char *) dtuple +
+ MAXALIGN(sizeof(BrinMemTuple) +
+ sizeof(BrinValues) *
brdesc->bd_tupdesc->natts);
for (i = 0; i < brdesc->bd_tupdesc->natts; i++)
{
dtuple->bt_columns[i].bv_allnulls = true;
dtuple->bt_columns[i].bv_hasnulls = false;
+
+ dtuple->bt_columns[i].bv_attno = i + 1;
+ dtuple->bt_columns[i].bv_allnulls = true;
+ dtuple->bt_columns[i].bv_hasnulls = false;
+ dtuple->bt_columns[i].bv_values = (Datum *) currdatum;
+ currdatum += sizeof(Datum) * brdesc->bd_info[i]->oi_nstored;
}
+
+ return dtuple;
}
/*
* Convert a BrinTuple back to a BrinMemTuple. This is the reverse of
* brin_form_tuple.
*
+ * As an optimization, the caller can pass a previously allocated 'dMemtuple'.
+ * This avoids having to allocate it here, which can be useful when this
+ * function is called many times in a loop. It is caller's responsibility
+ * that the given BrinMemTuple matches what we need here.
+ *
* Note we don't need the "on disk tupdesc" here; we rely on our own routine to
* deconstruct the tuple from the on-disk format.
*/
BrinMemTuple *
-brin_deform_tuple(BrinDesc *brdesc, BrinTuple *tuple)
+brin_deform_tuple(BrinDesc *brdesc, BrinTuple *tuple, BrinMemTuple *dMemtuple)
{
BrinMemTuple *dtup;
Datum *values;
@@ -407,15 +422,16 @@ brin_deform_tuple(BrinDesc *brdesc, BrinTuple *tuple)
int valueno;
MemoryContext oldcxt;
- dtup = brin_new_memtuple(brdesc);
+ dtup = dMemtuple ? brin_memtuple_initialize(dMemtuple, brdesc) :
+ brin_new_memtuple(brdesc);
if (BrinTupleIsPlaceholder(tuple))
dtup->bt_placeholder = true;
dtup->bt_blkno = tuple->bt_blkno;
- values = palloc(sizeof(Datum) * brdesc->bd_totalstored);
- allnulls = palloc(sizeof(bool) * brdesc->bd_tupdesc->natts);
- hasnulls = palloc(sizeof(bool) * brdesc->bd_tupdesc->natts);
+ values = dtup->bt_values;
+ allnulls = dtup->bt_allnulls;
+ hasnulls = dtup->bt_hasnulls;
tp = (char *) tuple + BrinTupleDataOffset(tuple);
@@ -458,10 +474,6 @@ brin_deform_tuple(BrinDesc *brdesc, BrinTuple *tuple)
MemoryContextSwitchTo(oldcxt);
- pfree(values);
- pfree(allnulls);
- pfree(hasnulls);
-
return dtup;
}
diff --git a/src/include/access/brin_tuple.h b/src/include/access/brin_tuple.h
index 6927865..86d8f98 100644
--- a/src/include/access/brin_tuple.h
+++ b/src/include/access/brin_tuple.h
@@ -38,6 +38,11 @@ typedef struct BrinMemTuple
bool bt_placeholder; /* this is a placeholder tuple */
BlockNumber bt_blkno; /* heap blkno that the tuple is for */
MemoryContext bt_context; /* memcxt holding the bt_columns values
*/
+ /* output arrays for brin_deform_tuple: */
+ Datum *bt_values; /* values array */
+ bool *bt_allnulls; /* allnulls array */
+ bool *bt_hasnulls; /* hasnulls array */
+ /* not an output array, but must be last */
BrinValues bt_columns[FLEXIBLE_ARRAY_MEMBER];
} BrinMemTuple;
@@ -88,9 +93,9 @@ extern bool brin_tuples_equal(const BrinTuple *a, Size alen,
const BrinTuple *b, Size blen);
extern BrinMemTuple *brin_new_memtuple(BrinDesc *brdesc);
-extern void brin_memtuple_initialize(BrinMemTuple *dtuple,
+extern BrinMemTuple *brin_memtuple_initialize(BrinMemTuple *dtuple,
BrinDesc *brdesc);
extern BrinMemTuple *brin_deform_tuple(BrinDesc *brdesc,
- BrinTuple *tuple);
+ BrinTuple *tuple, BrinMemTuple *dMemtuple);
#endif /* BRIN_TUPLE_H */
--
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