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Re: Inconsistent nullingrels due to oversight in deconstruct_distribute_oj_quals
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* Re: Inconsistent nullingrels due to oversight in deconstruct_distribute_oj_quals
@ 2023-02-10 08:27 Richard Guo <[email protected]>
  2023-02-10 18:40 ` Re: Inconsistent nullingrels due to oversight in deconstruct_distribute_oj_quals Tom Lane <[email protected]>
  0 siblings, 1 reply; 19+ messages in thread

From: Richard Guo @ 2023-02-10 08:27 UTC (permalink / raw)
  To: Tom Lane <[email protected]>; +Cc: pgsql-hackers

On Fri, Feb 10, 2023 at 11:08 AM Richard Guo <[email protected]> wrote:

> On Thu, Feb 9, 2023 at 11:55 PM Tom Lane <[email protected]> wrote:
>
>> Richard Guo <[email protected]> writes:
>> > This query would trigger the Assert() in search_indexed_tlist_for_var.
>> > So I wonder that we should use othersj->syn_righthand here.
>>
>> There are two such calls in deconstruct_distribute_oj_quals ...
>> don't they both need this change?
>
>
> Yeah, I wondered about that too, but didn't manage to devise a query
> that can show the problem caused by the call for 'above_sjinfo' case.
> After a night of sleep I came up with one this morning. :-)
>
> create table t (a int, b int);
>
> insert into t select i, i from generate_series(1,10)i;
> analyze t;
>
> select * from t t1 left join t t2 left join t t3 on t2.b = t3.b left join
> t t4 on t2.a > t3.a on t2.a > t1.a;
>
> In this query, for the qual 't2.a > t3.a', when we try to push t3/t4
> join to above t1/t2 join, we fail to add t1/t2 ojrelid to
> nullingrels of t3.a, because t3 is not in t1/t2 join's min_righthand
> (but in its syn_righthand).  We really should have done that because
> after the commutation t1/t2 join can null not only t2 but also t3 in
> this case.
>

However, for 'above_sjinfo' case, we should not use
othersj->syn_righthand,  because othersj->syn_righthand contains relids
in sjinfo's righthand which should not be nulled by othersj after the
commutation.  It seems what we should use here is sjinfo->syn_lefthand.

--- a/src/backend/optimizer/plan/initsplan.c
+++ b/src/backend/optimizer/plan/initsplan.c
@@ -1990,7 +1990,7 @@ deconstruct_distribute_oj_quals(PlannerInfo *root,
        if (above_sjinfo)
            quals = (List *)
                add_nulling_relids((Node *) quals,
-                                  othersj->min_righthand,
+                                  sjinfo->syn_lefthand,
                                   bms_make_singleton(othersj->ojrelid));

Thanks
Richard


^ permalink  raw  reply  [nested|flat] 19+ messages in thread

* Re: Inconsistent nullingrels due to oversight in deconstruct_distribute_oj_quals
  2023-02-10 08:27 Re: Inconsistent nullingrels due to oversight in deconstruct_distribute_oj_quals Richard Guo <[email protected]>
@ 2023-02-10 18:40 ` Tom Lane <[email protected]>
  0 siblings, 0 replies; 19+ messages in thread

From: Tom Lane @ 2023-02-10 18:40 UTC (permalink / raw)
  To: Richard Guo <[email protected]>; +Cc: pgsql-hackers; Robins Tharakan <[email protected]>

Richard Guo <[email protected]> writes:
> However, for 'above_sjinfo' case, we should not use
> othersj->syn_righthand,  because othersj->syn_righthand contains relids
> in sjinfo's righthand which should not be nulled by othersj after the
> commutation.  It seems what we should use here is sjinfo->syn_lefthand.

I had a hard time wrapping my brain around that to start with, but
now I think you're right.  othersj is syntactically above the current
join, so its syn_righthand will cover all of the current join, but
we only want to add nulling bits to Vars of the current join's LHS.
(That is, we need to transform Pbc to Pb*c, not Pb*c*.)

I also realized that there was a fairly critical nearby bug:
make_outerjoininfo was failing to check whether the upper join's qual
is actually of the form "Pbc", without any references to the lower join's
LHS.  So that led us to setting commute bits in some cases where we
shouldn't, further confusing deconstruct_distribute_oj_quals.  (I think
this snuck in because its other code path doesn't need to make such a
check, it being syntactically impossible to have such a reference if
we start from the other form of the identity.)

Fix pushed.  This seems to take care of Robins' latest example in
the bug #17781 thread [1], too.

			regards, tom lane

[1] https://postgr.es/m/CAEP4nAx9C5gXNBfEA0JBfz7B+5f1Bawt-RWQWyhev-wdps8BZA@mail.gmail.com






^ permalink  raw  reply  [nested|flat] 19+ messages in thread

* [PATCH v7 10/13] Hard-code TBMIterateResult offsets array size
@ 2024-02-16 01:13 Melanie Plageman <[email protected]>
  0 siblings, 0 replies; 19+ messages in thread

From: Melanie Plageman @ 2024-02-16 01:13 UTC (permalink / raw)

TIDBitmap's TBMIterateResult had a flexible sized array of tuple offsets
but the API always allocated MaxHeapTuplesPerPage OffsetNumbers.
Creating a fixed-size aray of size MaxHeapTuplesPerPage is more clear
for the API user.
---
 src/backend/nodes/tidbitmap.c | 29 +++++++----------------------
 src/include/nodes/tidbitmap.h | 12 ++++++++++--
 2 files changed, 17 insertions(+), 24 deletions(-)

diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index e8ab5d78fcc..d2bf8f44d50 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -40,7 +40,6 @@
 
 #include <limits.h>
 
-#include "access/htup_details.h"
 #include "common/hashfn.h"
 #include "common/int.h"
 #include "nodes/bitmapset.h"
@@ -48,14 +47,6 @@
 #include "storage/lwlock.h"
 #include "utils/dsa.h"
 
-/*
- * The maximum number of tuples per page is not large (typically 256 with
- * 8K pages, or 1024 with 32K pages).  So there's not much point in making
- * the per-page bitmaps variable size.  We just legislate that the size
- * is this:
- */
-#define MAX_TUPLES_PER_PAGE  MaxHeapTuplesPerPage
-
 /*
  * When we have to switch over to lossy storage, we use a data structure
  * with one bit per page, where all pages having the same number DIV
@@ -67,7 +58,7 @@
  * table, using identical data structures.  (This is because the memory
  * management for hashtables doesn't easily/efficiently allow space to be
  * transferred easily from one hashtable to another.)  Therefore it's best
- * if PAGES_PER_CHUNK is the same as MAX_TUPLES_PER_PAGE, or at least not
+ * if PAGES_PER_CHUNK is the same as MaxHeapTuplesPerPage, or at least not
  * too different.  But we also want PAGES_PER_CHUNK to be a power of 2 to
  * avoid expensive integer remainder operations.  So, define it like this:
  */
@@ -79,7 +70,7 @@
 #define BITNUM(x)	((x) % BITS_PER_BITMAPWORD)
 
 /* number of active words for an exact page: */
-#define WORDS_PER_PAGE	((MAX_TUPLES_PER_PAGE - 1) / BITS_PER_BITMAPWORD + 1)
+#define WORDS_PER_PAGE	((MaxHeapTuplesPerPage - 1) / BITS_PER_BITMAPWORD + 1)
 /* number of active words for a lossy chunk: */
 #define WORDS_PER_CHUNK  ((PAGES_PER_CHUNK - 1) / BITS_PER_BITMAPWORD + 1)
 
@@ -181,7 +172,7 @@ struct TBMIterator
 	int			spageptr;		/* next spages index */
 	int			schunkptr;		/* next schunks index */
 	int			schunkbit;		/* next bit to check in current schunk */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /*
@@ -222,7 +213,7 @@ struct TBMSharedIterator
 	PTEntryArray *ptbase;		/* pagetable element array */
 	PTIterationArray *ptpages;	/* sorted exact page index list */
 	PTIterationArray *ptchunks; /* sorted lossy page index list */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /* Local function prototypes */
@@ -390,7 +381,7 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointer tids, int ntids,
 					bitnum;
 
 		/* safety check to ensure we don't overrun bit array bounds */
-		if (off < 1 || off > MAX_TUPLES_PER_PAGE)
+		if (off < 1 || off > MaxHeapTuplesPerPage)
 			elog(ERROR, "tuple offset out of range: %u", off);
 
 		/*
@@ -692,12 +683,7 @@ tbm_begin_iterate(TIDBitmap *tbm)
 
 	Assert(tbm->iterating != TBM_ITERATING_SHARED);
 
-	/*
-	 * Create the TBMIterator struct, with enough trailing space to serve the
-	 * needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMIterator *) palloc(sizeof(TBMIterator) +
-									  MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = palloc(sizeof(TBMIterator));
 	iterator->tbm = tbm;
 
 	/*
@@ -1467,8 +1453,7 @@ tbm_attach_shared_iterate(dsa_area *dsa, dsa_pointer dp)
 	 * Create the TBMSharedIterator struct, with enough trailing space to
 	 * serve the needs of the TBMIterateResult sub-struct.
 	 */
-	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator) +
-											 MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator));
 
 	istate = (TBMSharedIteratorState *) dsa_get_address(dsa, dp);
 
diff --git a/src/include/nodes/tidbitmap.h b/src/include/nodes/tidbitmap.h
index 1945f0639bf..432fae52962 100644
--- a/src/include/nodes/tidbitmap.h
+++ b/src/include/nodes/tidbitmap.h
@@ -22,6 +22,7 @@
 #ifndef TIDBITMAP_H
 #define TIDBITMAP_H
 
+#include "access/htup_details.h"
 #include "storage/itemptr.h"
 #include "utils/dsa.h"
 
@@ -41,9 +42,16 @@ typedef struct TBMIterateResult
 {
 	BlockNumber blockno;		/* page number containing tuples */
 	int			ntuples;		/* -1 indicates lossy result */
-	bool		recheck;		/* should the tuples be rechecked? */
 	/* Note: recheck is always true if ntuples < 0 */
-	OffsetNumber offsets[FLEXIBLE_ARRAY_MEMBER];
+	bool		recheck;		/* should the tuples be rechecked? */
+
+	/*
+	 * The maximum number of tuples per page is not large (typically 256 with
+	 * 8K pages, or 1024 with 32K pages).  So there's not much point in making
+	 * the per-page bitmaps variable size.  We just legislate that the size is
+	 * this:
+	 */
+	OffsetNumber offsets[MaxHeapTuplesPerPage];
 } TBMIterateResult;
 
 /* function prototypes in nodes/tidbitmap.c */
-- 
2.40.1


--kqqpqghcwbcc3dt5
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v7-0011-Separate-TBM-Shared-Iterator-and-TBMIterateResult.patch"



^ permalink  raw  reply  [nested|flat] 19+ messages in thread

* [PATCH v6 11/14] Hard-code TBMIterateResult offsets array size
@ 2024-02-16 01:13 Melanie Plageman <[email protected]>
  0 siblings, 0 replies; 19+ messages in thread

From: Melanie Plageman @ 2024-02-16 01:13 UTC (permalink / raw)

TIDBitmap's TBMIterateResult had a flexible sized array of tuple offsets
but the API always allocated MaxHeapTuplesPerPage OffsetNumbers.
Creating a fixed-size aray of size MaxHeapTuplesPerPage is more clear
for the API user.
---
 src/backend/nodes/tidbitmap.c | 29 +++++++----------------------
 src/include/nodes/tidbitmap.h | 12 ++++++++++--
 2 files changed, 17 insertions(+), 24 deletions(-)

diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index e8ab5d78fcc..d2bf8f44d50 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -40,7 +40,6 @@
 
 #include <limits.h>
 
-#include "access/htup_details.h"
 #include "common/hashfn.h"
 #include "common/int.h"
 #include "nodes/bitmapset.h"
@@ -48,14 +47,6 @@
 #include "storage/lwlock.h"
 #include "utils/dsa.h"
 
-/*
- * The maximum number of tuples per page is not large (typically 256 with
- * 8K pages, or 1024 with 32K pages).  So there's not much point in making
- * the per-page bitmaps variable size.  We just legislate that the size
- * is this:
- */
-#define MAX_TUPLES_PER_PAGE  MaxHeapTuplesPerPage
-
 /*
  * When we have to switch over to lossy storage, we use a data structure
  * with one bit per page, where all pages having the same number DIV
@@ -67,7 +58,7 @@
  * table, using identical data structures.  (This is because the memory
  * management for hashtables doesn't easily/efficiently allow space to be
  * transferred easily from one hashtable to another.)  Therefore it's best
- * if PAGES_PER_CHUNK is the same as MAX_TUPLES_PER_PAGE, or at least not
+ * if PAGES_PER_CHUNK is the same as MaxHeapTuplesPerPage, or at least not
  * too different.  But we also want PAGES_PER_CHUNK to be a power of 2 to
  * avoid expensive integer remainder operations.  So, define it like this:
  */
@@ -79,7 +70,7 @@
 #define BITNUM(x)	((x) % BITS_PER_BITMAPWORD)
 
 /* number of active words for an exact page: */
-#define WORDS_PER_PAGE	((MAX_TUPLES_PER_PAGE - 1) / BITS_PER_BITMAPWORD + 1)
+#define WORDS_PER_PAGE	((MaxHeapTuplesPerPage - 1) / BITS_PER_BITMAPWORD + 1)
 /* number of active words for a lossy chunk: */
 #define WORDS_PER_CHUNK  ((PAGES_PER_CHUNK - 1) / BITS_PER_BITMAPWORD + 1)
 
@@ -181,7 +172,7 @@ struct TBMIterator
 	int			spageptr;		/* next spages index */
 	int			schunkptr;		/* next schunks index */
 	int			schunkbit;		/* next bit to check in current schunk */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /*
@@ -222,7 +213,7 @@ struct TBMSharedIterator
 	PTEntryArray *ptbase;		/* pagetable element array */
 	PTIterationArray *ptpages;	/* sorted exact page index list */
 	PTIterationArray *ptchunks; /* sorted lossy page index list */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /* Local function prototypes */
@@ -390,7 +381,7 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointer tids, int ntids,
 					bitnum;
 
 		/* safety check to ensure we don't overrun bit array bounds */
-		if (off < 1 || off > MAX_TUPLES_PER_PAGE)
+		if (off < 1 || off > MaxHeapTuplesPerPage)
 			elog(ERROR, "tuple offset out of range: %u", off);
 
 		/*
@@ -692,12 +683,7 @@ tbm_begin_iterate(TIDBitmap *tbm)
 
 	Assert(tbm->iterating != TBM_ITERATING_SHARED);
 
-	/*
-	 * Create the TBMIterator struct, with enough trailing space to serve the
-	 * needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMIterator *) palloc(sizeof(TBMIterator) +
-									  MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = palloc(sizeof(TBMIterator));
 	iterator->tbm = tbm;
 
 	/*
@@ -1467,8 +1453,7 @@ tbm_attach_shared_iterate(dsa_area *dsa, dsa_pointer dp)
 	 * Create the TBMSharedIterator struct, with enough trailing space to
 	 * serve the needs of the TBMIterateResult sub-struct.
 	 */
-	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator) +
-											 MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator));
 
 	istate = (TBMSharedIteratorState *) dsa_get_address(dsa, dp);
 
diff --git a/src/include/nodes/tidbitmap.h b/src/include/nodes/tidbitmap.h
index 1945f0639bf..432fae52962 100644
--- a/src/include/nodes/tidbitmap.h
+++ b/src/include/nodes/tidbitmap.h
@@ -22,6 +22,7 @@
 #ifndef TIDBITMAP_H
 #define TIDBITMAP_H
 
+#include "access/htup_details.h"
 #include "storage/itemptr.h"
 #include "utils/dsa.h"
 
@@ -41,9 +42,16 @@ typedef struct TBMIterateResult
 {
 	BlockNumber blockno;		/* page number containing tuples */
 	int			ntuples;		/* -1 indicates lossy result */
-	bool		recheck;		/* should the tuples be rechecked? */
 	/* Note: recheck is always true if ntuples < 0 */
-	OffsetNumber offsets[FLEXIBLE_ARRAY_MEMBER];
+	bool		recheck;		/* should the tuples be rechecked? */
+
+	/*
+	 * The maximum number of tuples per page is not large (typically 256 with
+	 * 8K pages, or 1024 with 32K pages).  So there's not much point in making
+	 * the per-page bitmaps variable size.  We just legislate that the size is
+	 * this:
+	 */
+	OffsetNumber offsets[MaxHeapTuplesPerPage];
 } TBMIterateResult;
 
 /* function prototypes in nodes/tidbitmap.c */
-- 
2.40.1


--w4wcjcocxsm37usi
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v6-0012-Separate-TBM-Shared-Iterator-and-TBMIterateResult.patch"



^ permalink  raw  reply  [nested|flat] 19+ messages in thread

* [PATCH v11 12/17] Hard-code TBMIterateResult offsets array size
@ 2024-02-16 01:13 Melanie Plageman <[email protected]>
  0 siblings, 0 replies; 19+ messages in thread

From: Melanie Plageman @ 2024-02-16 01:13 UTC (permalink / raw)

TIDBitmap's TBMIterateResult had a flexible sized array of tuple offsets
but the API always allocated MaxHeapTuplesPerPage OffsetNumbers.
Creating a fixed-size aray of size MaxHeapTuplesPerPage is more clear
for the API user.
---
 src/backend/nodes/tidbitmap.c | 33 +++++++--------------------------
 src/include/nodes/tidbitmap.h | 12 ++++++++++--
 2 files changed, 17 insertions(+), 28 deletions(-)

diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index e8ab5d78fc..1dc4c99bf9 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -40,7 +40,6 @@
 
 #include <limits.h>
 
-#include "access/htup_details.h"
 #include "common/hashfn.h"
 #include "common/int.h"
 #include "nodes/bitmapset.h"
@@ -48,14 +47,6 @@
 #include "storage/lwlock.h"
 #include "utils/dsa.h"
 
-/*
- * The maximum number of tuples per page is not large (typically 256 with
- * 8K pages, or 1024 with 32K pages).  So there's not much point in making
- * the per-page bitmaps variable size.  We just legislate that the size
- * is this:
- */
-#define MAX_TUPLES_PER_PAGE  MaxHeapTuplesPerPage
-
 /*
  * When we have to switch over to lossy storage, we use a data structure
  * with one bit per page, where all pages having the same number DIV
@@ -67,7 +58,7 @@
  * table, using identical data structures.  (This is because the memory
  * management for hashtables doesn't easily/efficiently allow space to be
  * transferred easily from one hashtable to another.)  Therefore it's best
- * if PAGES_PER_CHUNK is the same as MAX_TUPLES_PER_PAGE, or at least not
+ * if PAGES_PER_CHUNK is the same as MaxHeapTuplesPerPage, or at least not
  * too different.  But we also want PAGES_PER_CHUNK to be a power of 2 to
  * avoid expensive integer remainder operations.  So, define it like this:
  */
@@ -79,7 +70,7 @@
 #define BITNUM(x)	((x) % BITS_PER_BITMAPWORD)
 
 /* number of active words for an exact page: */
-#define WORDS_PER_PAGE	((MAX_TUPLES_PER_PAGE - 1) / BITS_PER_BITMAPWORD + 1)
+#define WORDS_PER_PAGE	((MaxHeapTuplesPerPage - 1) / BITS_PER_BITMAPWORD + 1)
 /* number of active words for a lossy chunk: */
 #define WORDS_PER_CHUNK  ((PAGES_PER_CHUNK - 1) / BITS_PER_BITMAPWORD + 1)
 
@@ -181,7 +172,7 @@ struct TBMIterator
 	int			spageptr;		/* next spages index */
 	int			schunkptr;		/* next schunks index */
 	int			schunkbit;		/* next bit to check in current schunk */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /*
@@ -222,7 +213,7 @@ struct TBMSharedIterator
 	PTEntryArray *ptbase;		/* pagetable element array */
 	PTIterationArray *ptpages;	/* sorted exact page index list */
 	PTIterationArray *ptchunks; /* sorted lossy page index list */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /* Local function prototypes */
@@ -390,7 +381,7 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointer tids, int ntids,
 					bitnum;
 
 		/* safety check to ensure we don't overrun bit array bounds */
-		if (off < 1 || off > MAX_TUPLES_PER_PAGE)
+		if (off < 1 || off > MaxHeapTuplesPerPage)
 			elog(ERROR, "tuple offset out of range: %u", off);
 
 		/*
@@ -692,12 +683,7 @@ tbm_begin_iterate(TIDBitmap *tbm)
 
 	Assert(tbm->iterating != TBM_ITERATING_SHARED);
 
-	/*
-	 * Create the TBMIterator struct, with enough trailing space to serve the
-	 * needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMIterator *) palloc(sizeof(TBMIterator) +
-									  MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = palloc(sizeof(TBMIterator));
 	iterator->tbm = tbm;
 
 	/*
@@ -1463,12 +1449,7 @@ tbm_attach_shared_iterate(dsa_area *dsa, dsa_pointer dp)
 	TBMSharedIterator *iterator;
 	TBMSharedIteratorState *istate;
 
-	/*
-	 * Create the TBMSharedIterator struct, with enough trailing space to
-	 * serve the needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator) +
-											 MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator));
 
 	istate = (TBMSharedIteratorState *) dsa_get_address(dsa, dp);
 
diff --git a/src/include/nodes/tidbitmap.h b/src/include/nodes/tidbitmap.h
index 1945f0639b..432fae5296 100644
--- a/src/include/nodes/tidbitmap.h
+++ b/src/include/nodes/tidbitmap.h
@@ -22,6 +22,7 @@
 #ifndef TIDBITMAP_H
 #define TIDBITMAP_H
 
+#include "access/htup_details.h"
 #include "storage/itemptr.h"
 #include "utils/dsa.h"
 
@@ -41,9 +42,16 @@ typedef struct TBMIterateResult
 {
 	BlockNumber blockno;		/* page number containing tuples */
 	int			ntuples;		/* -1 indicates lossy result */
-	bool		recheck;		/* should the tuples be rechecked? */
 	/* Note: recheck is always true if ntuples < 0 */
-	OffsetNumber offsets[FLEXIBLE_ARRAY_MEMBER];
+	bool		recheck;		/* should the tuples be rechecked? */
+
+	/*
+	 * The maximum number of tuples per page is not large (typically 256 with
+	 * 8K pages, or 1024 with 32K pages).  So there's not much point in making
+	 * the per-page bitmaps variable size.  We just legislate that the size is
+	 * this:
+	 */
+	OffsetNumber offsets[MaxHeapTuplesPerPage];
 } TBMIterateResult;
 
 /* function prototypes in nodes/tidbitmap.c */
-- 
2.40.1


--owzzsiozz6hgpp7e
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v11-0013-Separate-TBM-Shared-Iterator-and-TBMIterateResul.patch"



^ permalink  raw  reply  [nested|flat] 19+ messages in thread

* [PATCH v12 12/17] Hard-code TBMIterateResult offsets array size
@ 2024-02-16 01:13 Melanie Plageman <[email protected]>
  0 siblings, 0 replies; 19+ messages in thread

From: Melanie Plageman @ 2024-02-16 01:13 UTC (permalink / raw)

TIDBitmap's TBMIterateResult had a flexible sized array of tuple offsets
but the API always allocated MaxHeapTuplesPerPage OffsetNumbers.
Creating a fixed-size aray of size MaxHeapTuplesPerPage is more clear
for the API user.
---
 src/backend/nodes/tidbitmap.c | 33 +++++++--------------------------
 src/include/nodes/tidbitmap.h | 12 ++++++++++--
 2 files changed, 17 insertions(+), 28 deletions(-)

diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index e8ab5d78fcc..1dc4c99bf99 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -40,7 +40,6 @@
 
 #include <limits.h>
 
-#include "access/htup_details.h"
 #include "common/hashfn.h"
 #include "common/int.h"
 #include "nodes/bitmapset.h"
@@ -48,14 +47,6 @@
 #include "storage/lwlock.h"
 #include "utils/dsa.h"
 
-/*
- * The maximum number of tuples per page is not large (typically 256 with
- * 8K pages, or 1024 with 32K pages).  So there's not much point in making
- * the per-page bitmaps variable size.  We just legislate that the size
- * is this:
- */
-#define MAX_TUPLES_PER_PAGE  MaxHeapTuplesPerPage
-
 /*
  * When we have to switch over to lossy storage, we use a data structure
  * with one bit per page, where all pages having the same number DIV
@@ -67,7 +58,7 @@
  * table, using identical data structures.  (This is because the memory
  * management for hashtables doesn't easily/efficiently allow space to be
  * transferred easily from one hashtable to another.)  Therefore it's best
- * if PAGES_PER_CHUNK is the same as MAX_TUPLES_PER_PAGE, or at least not
+ * if PAGES_PER_CHUNK is the same as MaxHeapTuplesPerPage, or at least not
  * too different.  But we also want PAGES_PER_CHUNK to be a power of 2 to
  * avoid expensive integer remainder operations.  So, define it like this:
  */
@@ -79,7 +70,7 @@
 #define BITNUM(x)	((x) % BITS_PER_BITMAPWORD)
 
 /* number of active words for an exact page: */
-#define WORDS_PER_PAGE	((MAX_TUPLES_PER_PAGE - 1) / BITS_PER_BITMAPWORD + 1)
+#define WORDS_PER_PAGE	((MaxHeapTuplesPerPage - 1) / BITS_PER_BITMAPWORD + 1)
 /* number of active words for a lossy chunk: */
 #define WORDS_PER_CHUNK  ((PAGES_PER_CHUNK - 1) / BITS_PER_BITMAPWORD + 1)
 
@@ -181,7 +172,7 @@ struct TBMIterator
 	int			spageptr;		/* next spages index */
 	int			schunkptr;		/* next schunks index */
 	int			schunkbit;		/* next bit to check in current schunk */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /*
@@ -222,7 +213,7 @@ struct TBMSharedIterator
 	PTEntryArray *ptbase;		/* pagetable element array */
 	PTIterationArray *ptpages;	/* sorted exact page index list */
 	PTIterationArray *ptchunks; /* sorted lossy page index list */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /* Local function prototypes */
@@ -390,7 +381,7 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointer tids, int ntids,
 					bitnum;
 
 		/* safety check to ensure we don't overrun bit array bounds */
-		if (off < 1 || off > MAX_TUPLES_PER_PAGE)
+		if (off < 1 || off > MaxHeapTuplesPerPage)
 			elog(ERROR, "tuple offset out of range: %u", off);
 
 		/*
@@ -692,12 +683,7 @@ tbm_begin_iterate(TIDBitmap *tbm)
 
 	Assert(tbm->iterating != TBM_ITERATING_SHARED);
 
-	/*
-	 * Create the TBMIterator struct, with enough trailing space to serve the
-	 * needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMIterator *) palloc(sizeof(TBMIterator) +
-									  MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = palloc(sizeof(TBMIterator));
 	iterator->tbm = tbm;
 
 	/*
@@ -1463,12 +1449,7 @@ tbm_attach_shared_iterate(dsa_area *dsa, dsa_pointer dp)
 	TBMSharedIterator *iterator;
 	TBMSharedIteratorState *istate;
 
-	/*
-	 * Create the TBMSharedIterator struct, with enough trailing space to
-	 * serve the needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator) +
-											 MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator));
 
 	istate = (TBMSharedIteratorState *) dsa_get_address(dsa, dp);
 
diff --git a/src/include/nodes/tidbitmap.h b/src/include/nodes/tidbitmap.h
index 1945f0639bf..432fae52962 100644
--- a/src/include/nodes/tidbitmap.h
+++ b/src/include/nodes/tidbitmap.h
@@ -22,6 +22,7 @@
 #ifndef TIDBITMAP_H
 #define TIDBITMAP_H
 
+#include "access/htup_details.h"
 #include "storage/itemptr.h"
 #include "utils/dsa.h"
 
@@ -41,9 +42,16 @@ typedef struct TBMIterateResult
 {
 	BlockNumber blockno;		/* page number containing tuples */
 	int			ntuples;		/* -1 indicates lossy result */
-	bool		recheck;		/* should the tuples be rechecked? */
 	/* Note: recheck is always true if ntuples < 0 */
-	OffsetNumber offsets[FLEXIBLE_ARRAY_MEMBER];
+	bool		recheck;		/* should the tuples be rechecked? */
+
+	/*
+	 * The maximum number of tuples per page is not large (typically 256 with
+	 * 8K pages, or 1024 with 32K pages).  So there's not much point in making
+	 * the per-page bitmaps variable size.  We just legislate that the size is
+	 * this:
+	 */
+	OffsetNumber offsets[MaxHeapTuplesPerPage];
 } TBMIterateResult;
 
 /* function prototypes in nodes/tidbitmap.c */
-- 
2.40.1


--6jpz2j246qmht4bt
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v12-0013-Separate-TBM-Shared-Iterator-and-TBMIterateResul.patch"



^ permalink  raw  reply  [nested|flat] 19+ messages in thread

* [PATCH v9 11/17] Hard-code TBMIterateResult offsets array size
@ 2024-02-16 01:13 Melanie Plageman <[email protected]>
  0 siblings, 0 replies; 19+ messages in thread

From: Melanie Plageman @ 2024-02-16 01:13 UTC (permalink / raw)

TIDBitmap's TBMIterateResult had a flexible sized array of tuple offsets
but the API always allocated MaxHeapTuplesPerPage OffsetNumbers.
Creating a fixed-size aray of size MaxHeapTuplesPerPage is more clear
for the API user.
---
 src/backend/nodes/tidbitmap.c | 33 +++++++--------------------------
 src/include/nodes/tidbitmap.h | 12 ++++++++++--
 2 files changed, 17 insertions(+), 28 deletions(-)

diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index e8ab5d78fc..1dc4c99bf9 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -40,7 +40,6 @@
 
 #include <limits.h>
 
-#include "access/htup_details.h"
 #include "common/hashfn.h"
 #include "common/int.h"
 #include "nodes/bitmapset.h"
@@ -48,14 +47,6 @@
 #include "storage/lwlock.h"
 #include "utils/dsa.h"
 
-/*
- * The maximum number of tuples per page is not large (typically 256 with
- * 8K pages, or 1024 with 32K pages).  So there's not much point in making
- * the per-page bitmaps variable size.  We just legislate that the size
- * is this:
- */
-#define MAX_TUPLES_PER_PAGE  MaxHeapTuplesPerPage
-
 /*
  * When we have to switch over to lossy storage, we use a data structure
  * with one bit per page, where all pages having the same number DIV
@@ -67,7 +58,7 @@
  * table, using identical data structures.  (This is because the memory
  * management for hashtables doesn't easily/efficiently allow space to be
  * transferred easily from one hashtable to another.)  Therefore it's best
- * if PAGES_PER_CHUNK is the same as MAX_TUPLES_PER_PAGE, or at least not
+ * if PAGES_PER_CHUNK is the same as MaxHeapTuplesPerPage, or at least not
  * too different.  But we also want PAGES_PER_CHUNK to be a power of 2 to
  * avoid expensive integer remainder operations.  So, define it like this:
  */
@@ -79,7 +70,7 @@
 #define BITNUM(x)	((x) % BITS_PER_BITMAPWORD)
 
 /* number of active words for an exact page: */
-#define WORDS_PER_PAGE	((MAX_TUPLES_PER_PAGE - 1) / BITS_PER_BITMAPWORD + 1)
+#define WORDS_PER_PAGE	((MaxHeapTuplesPerPage - 1) / BITS_PER_BITMAPWORD + 1)
 /* number of active words for a lossy chunk: */
 #define WORDS_PER_CHUNK  ((PAGES_PER_CHUNK - 1) / BITS_PER_BITMAPWORD + 1)
 
@@ -181,7 +172,7 @@ struct TBMIterator
 	int			spageptr;		/* next spages index */
 	int			schunkptr;		/* next schunks index */
 	int			schunkbit;		/* next bit to check in current schunk */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /*
@@ -222,7 +213,7 @@ struct TBMSharedIterator
 	PTEntryArray *ptbase;		/* pagetable element array */
 	PTIterationArray *ptpages;	/* sorted exact page index list */
 	PTIterationArray *ptchunks; /* sorted lossy page index list */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /* Local function prototypes */
@@ -390,7 +381,7 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointer tids, int ntids,
 					bitnum;
 
 		/* safety check to ensure we don't overrun bit array bounds */
-		if (off < 1 || off > MAX_TUPLES_PER_PAGE)
+		if (off < 1 || off > MaxHeapTuplesPerPage)
 			elog(ERROR, "tuple offset out of range: %u", off);
 
 		/*
@@ -692,12 +683,7 @@ tbm_begin_iterate(TIDBitmap *tbm)
 
 	Assert(tbm->iterating != TBM_ITERATING_SHARED);
 
-	/*
-	 * Create the TBMIterator struct, with enough trailing space to serve the
-	 * needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMIterator *) palloc(sizeof(TBMIterator) +
-									  MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = palloc(sizeof(TBMIterator));
 	iterator->tbm = tbm;
 
 	/*
@@ -1463,12 +1449,7 @@ tbm_attach_shared_iterate(dsa_area *dsa, dsa_pointer dp)
 	TBMSharedIterator *iterator;
 	TBMSharedIteratorState *istate;
 
-	/*
-	 * Create the TBMSharedIterator struct, with enough trailing space to
-	 * serve the needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator) +
-											 MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator));
 
 	istate = (TBMSharedIteratorState *) dsa_get_address(dsa, dp);
 
diff --git a/src/include/nodes/tidbitmap.h b/src/include/nodes/tidbitmap.h
index 1945f0639b..432fae5296 100644
--- a/src/include/nodes/tidbitmap.h
+++ b/src/include/nodes/tidbitmap.h
@@ -22,6 +22,7 @@
 #ifndef TIDBITMAP_H
 #define TIDBITMAP_H
 
+#include "access/htup_details.h"
 #include "storage/itemptr.h"
 #include "utils/dsa.h"
 
@@ -41,9 +42,16 @@ typedef struct TBMIterateResult
 {
 	BlockNumber blockno;		/* page number containing tuples */
 	int			ntuples;		/* -1 indicates lossy result */
-	bool		recheck;		/* should the tuples be rechecked? */
 	/* Note: recheck is always true if ntuples < 0 */
-	OffsetNumber offsets[FLEXIBLE_ARRAY_MEMBER];
+	bool		recheck;		/* should the tuples be rechecked? */
+
+	/*
+	 * The maximum number of tuples per page is not large (typically 256 with
+	 * 8K pages, or 1024 with 32K pages).  So there's not much point in making
+	 * the per-page bitmaps variable size.  We just legislate that the size is
+	 * this:
+	 */
+	OffsetNumber offsets[MaxHeapTuplesPerPage];
 } TBMIterateResult;
 
 /* function prototypes in nodes/tidbitmap.c */
-- 
2.40.1


--7mdtsjmrzitrgzgx
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v9-0012-Separate-TBM-Shared-Iterator-and-TBMIterateResult.patch"



^ permalink  raw  reply  [nested|flat] 19+ messages in thread

* [PATCH v8 10/17] Hard-code TBMIterateResult offsets array size
@ 2024-02-16 01:13 Melanie Plageman <[email protected]>
  0 siblings, 0 replies; 19+ messages in thread

From: Melanie Plageman @ 2024-02-16 01:13 UTC (permalink / raw)

TIDBitmap's TBMIterateResult had a flexible sized array of tuple offsets
but the API always allocated MaxHeapTuplesPerPage OffsetNumbers.
Creating a fixed-size aray of size MaxHeapTuplesPerPage is more clear
for the API user.
---
 src/backend/nodes/tidbitmap.c | 33 +++++++--------------------------
 src/include/nodes/tidbitmap.h | 12 ++++++++++--
 2 files changed, 17 insertions(+), 28 deletions(-)

diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index e8ab5d78fc..1dc4c99bf9 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -40,7 +40,6 @@
 
 #include <limits.h>
 
-#include "access/htup_details.h"
 #include "common/hashfn.h"
 #include "common/int.h"
 #include "nodes/bitmapset.h"
@@ -48,14 +47,6 @@
 #include "storage/lwlock.h"
 #include "utils/dsa.h"
 
-/*
- * The maximum number of tuples per page is not large (typically 256 with
- * 8K pages, or 1024 with 32K pages).  So there's not much point in making
- * the per-page bitmaps variable size.  We just legislate that the size
- * is this:
- */
-#define MAX_TUPLES_PER_PAGE  MaxHeapTuplesPerPage
-
 /*
  * When we have to switch over to lossy storage, we use a data structure
  * with one bit per page, where all pages having the same number DIV
@@ -67,7 +58,7 @@
  * table, using identical data structures.  (This is because the memory
  * management for hashtables doesn't easily/efficiently allow space to be
  * transferred easily from one hashtable to another.)  Therefore it's best
- * if PAGES_PER_CHUNK is the same as MAX_TUPLES_PER_PAGE, or at least not
+ * if PAGES_PER_CHUNK is the same as MaxHeapTuplesPerPage, or at least not
  * too different.  But we also want PAGES_PER_CHUNK to be a power of 2 to
  * avoid expensive integer remainder operations.  So, define it like this:
  */
@@ -79,7 +70,7 @@
 #define BITNUM(x)	((x) % BITS_PER_BITMAPWORD)
 
 /* number of active words for an exact page: */
-#define WORDS_PER_PAGE	((MAX_TUPLES_PER_PAGE - 1) / BITS_PER_BITMAPWORD + 1)
+#define WORDS_PER_PAGE	((MaxHeapTuplesPerPage - 1) / BITS_PER_BITMAPWORD + 1)
 /* number of active words for a lossy chunk: */
 #define WORDS_PER_CHUNK  ((PAGES_PER_CHUNK - 1) / BITS_PER_BITMAPWORD + 1)
 
@@ -181,7 +172,7 @@ struct TBMIterator
 	int			spageptr;		/* next spages index */
 	int			schunkptr;		/* next schunks index */
 	int			schunkbit;		/* next bit to check in current schunk */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /*
@@ -222,7 +213,7 @@ struct TBMSharedIterator
 	PTEntryArray *ptbase;		/* pagetable element array */
 	PTIterationArray *ptpages;	/* sorted exact page index list */
 	PTIterationArray *ptchunks; /* sorted lossy page index list */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /* Local function prototypes */
@@ -390,7 +381,7 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointer tids, int ntids,
 					bitnum;
 
 		/* safety check to ensure we don't overrun bit array bounds */
-		if (off < 1 || off > MAX_TUPLES_PER_PAGE)
+		if (off < 1 || off > MaxHeapTuplesPerPage)
 			elog(ERROR, "tuple offset out of range: %u", off);
 
 		/*
@@ -692,12 +683,7 @@ tbm_begin_iterate(TIDBitmap *tbm)
 
 	Assert(tbm->iterating != TBM_ITERATING_SHARED);
 
-	/*
-	 * Create the TBMIterator struct, with enough trailing space to serve the
-	 * needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMIterator *) palloc(sizeof(TBMIterator) +
-									  MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = palloc(sizeof(TBMIterator));
 	iterator->tbm = tbm;
 
 	/*
@@ -1463,12 +1449,7 @@ tbm_attach_shared_iterate(dsa_area *dsa, dsa_pointer dp)
 	TBMSharedIterator *iterator;
 	TBMSharedIteratorState *istate;
 
-	/*
-	 * Create the TBMSharedIterator struct, with enough trailing space to
-	 * serve the needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator) +
-											 MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator));
 
 	istate = (TBMSharedIteratorState *) dsa_get_address(dsa, dp);
 
diff --git a/src/include/nodes/tidbitmap.h b/src/include/nodes/tidbitmap.h
index 1945f0639b..432fae5296 100644
--- a/src/include/nodes/tidbitmap.h
+++ b/src/include/nodes/tidbitmap.h
@@ -22,6 +22,7 @@
 #ifndef TIDBITMAP_H
 #define TIDBITMAP_H
 
+#include "access/htup_details.h"
 #include "storage/itemptr.h"
 #include "utils/dsa.h"
 
@@ -41,9 +42,16 @@ typedef struct TBMIterateResult
 {
 	BlockNumber blockno;		/* page number containing tuples */
 	int			ntuples;		/* -1 indicates lossy result */
-	bool		recheck;		/* should the tuples be rechecked? */
 	/* Note: recheck is always true if ntuples < 0 */
-	OffsetNumber offsets[FLEXIBLE_ARRAY_MEMBER];
+	bool		recheck;		/* should the tuples be rechecked? */
+
+	/*
+	 * The maximum number of tuples per page is not large (typically 256 with
+	 * 8K pages, or 1024 with 32K pages).  So there's not much point in making
+	 * the per-page bitmaps variable size.  We just legislate that the size is
+	 * this:
+	 */
+	OffsetNumber offsets[MaxHeapTuplesPerPage];
 } TBMIterateResult;
 
 /* function prototypes in nodes/tidbitmap.c */
-- 
2.40.1


--xqq4defy3uncu6k6
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v8-0011-table_scan_bitmap_next_block-counts-lossy-and-exa.patch"



^ permalink  raw  reply  [nested|flat] 19+ messages in thread

* [PATCH v9 11/17] Hard-code TBMIterateResult offsets array size
@ 2024-02-16 01:13 Melanie Plageman <[email protected]>
  0 siblings, 0 replies; 19+ messages in thread

From: Melanie Plageman @ 2024-02-16 01:13 UTC (permalink / raw)

TIDBitmap's TBMIterateResult had a flexible sized array of tuple offsets
but the API always allocated MaxHeapTuplesPerPage OffsetNumbers.
Creating a fixed-size aray of size MaxHeapTuplesPerPage is more clear
for the API user.
---
 src/backend/nodes/tidbitmap.c | 33 +++++++--------------------------
 src/include/nodes/tidbitmap.h | 12 ++++++++++--
 2 files changed, 17 insertions(+), 28 deletions(-)

diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index e8ab5d78fc..1dc4c99bf9 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -40,7 +40,6 @@
 
 #include <limits.h>
 
-#include "access/htup_details.h"
 #include "common/hashfn.h"
 #include "common/int.h"
 #include "nodes/bitmapset.h"
@@ -48,14 +47,6 @@
 #include "storage/lwlock.h"
 #include "utils/dsa.h"
 
-/*
- * The maximum number of tuples per page is not large (typically 256 with
- * 8K pages, or 1024 with 32K pages).  So there's not much point in making
- * the per-page bitmaps variable size.  We just legislate that the size
- * is this:
- */
-#define MAX_TUPLES_PER_PAGE  MaxHeapTuplesPerPage
-
 /*
  * When we have to switch over to lossy storage, we use a data structure
  * with one bit per page, where all pages having the same number DIV
@@ -67,7 +58,7 @@
  * table, using identical data structures.  (This is because the memory
  * management for hashtables doesn't easily/efficiently allow space to be
  * transferred easily from one hashtable to another.)  Therefore it's best
- * if PAGES_PER_CHUNK is the same as MAX_TUPLES_PER_PAGE, or at least not
+ * if PAGES_PER_CHUNK is the same as MaxHeapTuplesPerPage, or at least not
  * too different.  But we also want PAGES_PER_CHUNK to be a power of 2 to
  * avoid expensive integer remainder operations.  So, define it like this:
  */
@@ -79,7 +70,7 @@
 #define BITNUM(x)	((x) % BITS_PER_BITMAPWORD)
 
 /* number of active words for an exact page: */
-#define WORDS_PER_PAGE	((MAX_TUPLES_PER_PAGE - 1) / BITS_PER_BITMAPWORD + 1)
+#define WORDS_PER_PAGE	((MaxHeapTuplesPerPage - 1) / BITS_PER_BITMAPWORD + 1)
 /* number of active words for a lossy chunk: */
 #define WORDS_PER_CHUNK  ((PAGES_PER_CHUNK - 1) / BITS_PER_BITMAPWORD + 1)
 
@@ -181,7 +172,7 @@ struct TBMIterator
 	int			spageptr;		/* next spages index */
 	int			schunkptr;		/* next schunks index */
 	int			schunkbit;		/* next bit to check in current schunk */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /*
@@ -222,7 +213,7 @@ struct TBMSharedIterator
 	PTEntryArray *ptbase;		/* pagetable element array */
 	PTIterationArray *ptpages;	/* sorted exact page index list */
 	PTIterationArray *ptchunks; /* sorted lossy page index list */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /* Local function prototypes */
@@ -390,7 +381,7 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointer tids, int ntids,
 					bitnum;
 
 		/* safety check to ensure we don't overrun bit array bounds */
-		if (off < 1 || off > MAX_TUPLES_PER_PAGE)
+		if (off < 1 || off > MaxHeapTuplesPerPage)
 			elog(ERROR, "tuple offset out of range: %u", off);
 
 		/*
@@ -692,12 +683,7 @@ tbm_begin_iterate(TIDBitmap *tbm)
 
 	Assert(tbm->iterating != TBM_ITERATING_SHARED);
 
-	/*
-	 * Create the TBMIterator struct, with enough trailing space to serve the
-	 * needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMIterator *) palloc(sizeof(TBMIterator) +
-									  MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = palloc(sizeof(TBMIterator));
 	iterator->tbm = tbm;
 
 	/*
@@ -1463,12 +1449,7 @@ tbm_attach_shared_iterate(dsa_area *dsa, dsa_pointer dp)
 	TBMSharedIterator *iterator;
 	TBMSharedIteratorState *istate;
 
-	/*
-	 * Create the TBMSharedIterator struct, with enough trailing space to
-	 * serve the needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator) +
-											 MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator));
 
 	istate = (TBMSharedIteratorState *) dsa_get_address(dsa, dp);
 
diff --git a/src/include/nodes/tidbitmap.h b/src/include/nodes/tidbitmap.h
index 1945f0639b..432fae5296 100644
--- a/src/include/nodes/tidbitmap.h
+++ b/src/include/nodes/tidbitmap.h
@@ -22,6 +22,7 @@
 #ifndef TIDBITMAP_H
 #define TIDBITMAP_H
 
+#include "access/htup_details.h"
 #include "storage/itemptr.h"
 #include "utils/dsa.h"
 
@@ -41,9 +42,16 @@ typedef struct TBMIterateResult
 {
 	BlockNumber blockno;		/* page number containing tuples */
 	int			ntuples;		/* -1 indicates lossy result */
-	bool		recheck;		/* should the tuples be rechecked? */
 	/* Note: recheck is always true if ntuples < 0 */
-	OffsetNumber offsets[FLEXIBLE_ARRAY_MEMBER];
+	bool		recheck;		/* should the tuples be rechecked? */
+
+	/*
+	 * The maximum number of tuples per page is not large (typically 256 with
+	 * 8K pages, or 1024 with 32K pages).  So there's not much point in making
+	 * the per-page bitmaps variable size.  We just legislate that the size is
+	 * this:
+	 */
+	OffsetNumber offsets[MaxHeapTuplesPerPage];
 } TBMIterateResult;
 
 /* function prototypes in nodes/tidbitmap.c */
-- 
2.40.1


--7mdtsjmrzitrgzgx
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v9-0012-Separate-TBM-Shared-Iterator-and-TBMIterateResult.patch"



^ permalink  raw  reply  [nested|flat] 19+ messages in thread

* [PATCH v7 10/13] Hard-code TBMIterateResult offsets array size
@ 2024-02-16 01:13 Melanie Plageman <[email protected]>
  0 siblings, 0 replies; 19+ messages in thread

From: Melanie Plageman @ 2024-02-16 01:13 UTC (permalink / raw)

TIDBitmap's TBMIterateResult had a flexible sized array of tuple offsets
but the API always allocated MaxHeapTuplesPerPage OffsetNumbers.
Creating a fixed-size aray of size MaxHeapTuplesPerPage is more clear
for the API user.
---
 src/backend/nodes/tidbitmap.c | 29 +++++++----------------------
 src/include/nodes/tidbitmap.h | 12 ++++++++++--
 2 files changed, 17 insertions(+), 24 deletions(-)

diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index e8ab5d78fcc..d2bf8f44d50 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -40,7 +40,6 @@
 
 #include <limits.h>
 
-#include "access/htup_details.h"
 #include "common/hashfn.h"
 #include "common/int.h"
 #include "nodes/bitmapset.h"
@@ -48,14 +47,6 @@
 #include "storage/lwlock.h"
 #include "utils/dsa.h"
 
-/*
- * The maximum number of tuples per page is not large (typically 256 with
- * 8K pages, or 1024 with 32K pages).  So there's not much point in making
- * the per-page bitmaps variable size.  We just legislate that the size
- * is this:
- */
-#define MAX_TUPLES_PER_PAGE  MaxHeapTuplesPerPage
-
 /*
  * When we have to switch over to lossy storage, we use a data structure
  * with one bit per page, where all pages having the same number DIV
@@ -67,7 +58,7 @@
  * table, using identical data structures.  (This is because the memory
  * management for hashtables doesn't easily/efficiently allow space to be
  * transferred easily from one hashtable to another.)  Therefore it's best
- * if PAGES_PER_CHUNK is the same as MAX_TUPLES_PER_PAGE, or at least not
+ * if PAGES_PER_CHUNK is the same as MaxHeapTuplesPerPage, or at least not
  * too different.  But we also want PAGES_PER_CHUNK to be a power of 2 to
  * avoid expensive integer remainder operations.  So, define it like this:
  */
@@ -79,7 +70,7 @@
 #define BITNUM(x)	((x) % BITS_PER_BITMAPWORD)
 
 /* number of active words for an exact page: */
-#define WORDS_PER_PAGE	((MAX_TUPLES_PER_PAGE - 1) / BITS_PER_BITMAPWORD + 1)
+#define WORDS_PER_PAGE	((MaxHeapTuplesPerPage - 1) / BITS_PER_BITMAPWORD + 1)
 /* number of active words for a lossy chunk: */
 #define WORDS_PER_CHUNK  ((PAGES_PER_CHUNK - 1) / BITS_PER_BITMAPWORD + 1)
 
@@ -181,7 +172,7 @@ struct TBMIterator
 	int			spageptr;		/* next spages index */
 	int			schunkptr;		/* next schunks index */
 	int			schunkbit;		/* next bit to check in current schunk */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /*
@@ -222,7 +213,7 @@ struct TBMSharedIterator
 	PTEntryArray *ptbase;		/* pagetable element array */
 	PTIterationArray *ptpages;	/* sorted exact page index list */
 	PTIterationArray *ptchunks; /* sorted lossy page index list */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /* Local function prototypes */
@@ -390,7 +381,7 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointer tids, int ntids,
 					bitnum;
 
 		/* safety check to ensure we don't overrun bit array bounds */
-		if (off < 1 || off > MAX_TUPLES_PER_PAGE)
+		if (off < 1 || off > MaxHeapTuplesPerPage)
 			elog(ERROR, "tuple offset out of range: %u", off);
 
 		/*
@@ -692,12 +683,7 @@ tbm_begin_iterate(TIDBitmap *tbm)
 
 	Assert(tbm->iterating != TBM_ITERATING_SHARED);
 
-	/*
-	 * Create the TBMIterator struct, with enough trailing space to serve the
-	 * needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMIterator *) palloc(sizeof(TBMIterator) +
-									  MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = palloc(sizeof(TBMIterator));
 	iterator->tbm = tbm;
 
 	/*
@@ -1467,8 +1453,7 @@ tbm_attach_shared_iterate(dsa_area *dsa, dsa_pointer dp)
 	 * Create the TBMSharedIterator struct, with enough trailing space to
 	 * serve the needs of the TBMIterateResult sub-struct.
 	 */
-	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator) +
-											 MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator));
 
 	istate = (TBMSharedIteratorState *) dsa_get_address(dsa, dp);
 
diff --git a/src/include/nodes/tidbitmap.h b/src/include/nodes/tidbitmap.h
index 1945f0639bf..432fae52962 100644
--- a/src/include/nodes/tidbitmap.h
+++ b/src/include/nodes/tidbitmap.h
@@ -22,6 +22,7 @@
 #ifndef TIDBITMAP_H
 #define TIDBITMAP_H
 
+#include "access/htup_details.h"
 #include "storage/itemptr.h"
 #include "utils/dsa.h"
 
@@ -41,9 +42,16 @@ typedef struct TBMIterateResult
 {
 	BlockNumber blockno;		/* page number containing tuples */
 	int			ntuples;		/* -1 indicates lossy result */
-	bool		recheck;		/* should the tuples be rechecked? */
 	/* Note: recheck is always true if ntuples < 0 */
-	OffsetNumber offsets[FLEXIBLE_ARRAY_MEMBER];
+	bool		recheck;		/* should the tuples be rechecked? */
+
+	/*
+	 * The maximum number of tuples per page is not large (typically 256 with
+	 * 8K pages, or 1024 with 32K pages).  So there's not much point in making
+	 * the per-page bitmaps variable size.  We just legislate that the size is
+	 * this:
+	 */
+	OffsetNumber offsets[MaxHeapTuplesPerPage];
 } TBMIterateResult;
 
 /* function prototypes in nodes/tidbitmap.c */
-- 
2.40.1


--kqqpqghcwbcc3dt5
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v7-0011-Separate-TBM-Shared-Iterator-and-TBMIterateResult.patch"



^ permalink  raw  reply  [nested|flat] 19+ messages in thread

* [PATCH v6 11/14] Hard-code TBMIterateResult offsets array size
@ 2024-02-16 01:13 Melanie Plageman <[email protected]>
  0 siblings, 0 replies; 19+ messages in thread

From: Melanie Plageman @ 2024-02-16 01:13 UTC (permalink / raw)

TIDBitmap's TBMIterateResult had a flexible sized array of tuple offsets
but the API always allocated MaxHeapTuplesPerPage OffsetNumbers.
Creating a fixed-size aray of size MaxHeapTuplesPerPage is more clear
for the API user.
---
 src/backend/nodes/tidbitmap.c | 29 +++++++----------------------
 src/include/nodes/tidbitmap.h | 12 ++++++++++--
 2 files changed, 17 insertions(+), 24 deletions(-)

diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index e8ab5d78fcc..d2bf8f44d50 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -40,7 +40,6 @@
 
 #include <limits.h>
 
-#include "access/htup_details.h"
 #include "common/hashfn.h"
 #include "common/int.h"
 #include "nodes/bitmapset.h"
@@ -48,14 +47,6 @@
 #include "storage/lwlock.h"
 #include "utils/dsa.h"
 
-/*
- * The maximum number of tuples per page is not large (typically 256 with
- * 8K pages, or 1024 with 32K pages).  So there's not much point in making
- * the per-page bitmaps variable size.  We just legislate that the size
- * is this:
- */
-#define MAX_TUPLES_PER_PAGE  MaxHeapTuplesPerPage
-
 /*
  * When we have to switch over to lossy storage, we use a data structure
  * with one bit per page, where all pages having the same number DIV
@@ -67,7 +58,7 @@
  * table, using identical data structures.  (This is because the memory
  * management for hashtables doesn't easily/efficiently allow space to be
  * transferred easily from one hashtable to another.)  Therefore it's best
- * if PAGES_PER_CHUNK is the same as MAX_TUPLES_PER_PAGE, or at least not
+ * if PAGES_PER_CHUNK is the same as MaxHeapTuplesPerPage, or at least not
  * too different.  But we also want PAGES_PER_CHUNK to be a power of 2 to
  * avoid expensive integer remainder operations.  So, define it like this:
  */
@@ -79,7 +70,7 @@
 #define BITNUM(x)	((x) % BITS_PER_BITMAPWORD)
 
 /* number of active words for an exact page: */
-#define WORDS_PER_PAGE	((MAX_TUPLES_PER_PAGE - 1) / BITS_PER_BITMAPWORD + 1)
+#define WORDS_PER_PAGE	((MaxHeapTuplesPerPage - 1) / BITS_PER_BITMAPWORD + 1)
 /* number of active words for a lossy chunk: */
 #define WORDS_PER_CHUNK  ((PAGES_PER_CHUNK - 1) / BITS_PER_BITMAPWORD + 1)
 
@@ -181,7 +172,7 @@ struct TBMIterator
 	int			spageptr;		/* next spages index */
 	int			schunkptr;		/* next schunks index */
 	int			schunkbit;		/* next bit to check in current schunk */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /*
@@ -222,7 +213,7 @@ struct TBMSharedIterator
 	PTEntryArray *ptbase;		/* pagetable element array */
 	PTIterationArray *ptpages;	/* sorted exact page index list */
 	PTIterationArray *ptchunks; /* sorted lossy page index list */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /* Local function prototypes */
@@ -390,7 +381,7 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointer tids, int ntids,
 					bitnum;
 
 		/* safety check to ensure we don't overrun bit array bounds */
-		if (off < 1 || off > MAX_TUPLES_PER_PAGE)
+		if (off < 1 || off > MaxHeapTuplesPerPage)
 			elog(ERROR, "tuple offset out of range: %u", off);
 
 		/*
@@ -692,12 +683,7 @@ tbm_begin_iterate(TIDBitmap *tbm)
 
 	Assert(tbm->iterating != TBM_ITERATING_SHARED);
 
-	/*
-	 * Create the TBMIterator struct, with enough trailing space to serve the
-	 * needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMIterator *) palloc(sizeof(TBMIterator) +
-									  MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = palloc(sizeof(TBMIterator));
 	iterator->tbm = tbm;
 
 	/*
@@ -1467,8 +1453,7 @@ tbm_attach_shared_iterate(dsa_area *dsa, dsa_pointer dp)
 	 * Create the TBMSharedIterator struct, with enough trailing space to
 	 * serve the needs of the TBMIterateResult sub-struct.
 	 */
-	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator) +
-											 MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator));
 
 	istate = (TBMSharedIteratorState *) dsa_get_address(dsa, dp);
 
diff --git a/src/include/nodes/tidbitmap.h b/src/include/nodes/tidbitmap.h
index 1945f0639bf..432fae52962 100644
--- a/src/include/nodes/tidbitmap.h
+++ b/src/include/nodes/tidbitmap.h
@@ -22,6 +22,7 @@
 #ifndef TIDBITMAP_H
 #define TIDBITMAP_H
 
+#include "access/htup_details.h"
 #include "storage/itemptr.h"
 #include "utils/dsa.h"
 
@@ -41,9 +42,16 @@ typedef struct TBMIterateResult
 {
 	BlockNumber blockno;		/* page number containing tuples */
 	int			ntuples;		/* -1 indicates lossy result */
-	bool		recheck;		/* should the tuples be rechecked? */
 	/* Note: recheck is always true if ntuples < 0 */
-	OffsetNumber offsets[FLEXIBLE_ARRAY_MEMBER];
+	bool		recheck;		/* should the tuples be rechecked? */
+
+	/*
+	 * The maximum number of tuples per page is not large (typically 256 with
+	 * 8K pages, or 1024 with 32K pages).  So there's not much point in making
+	 * the per-page bitmaps variable size.  We just legislate that the size is
+	 * this:
+	 */
+	OffsetNumber offsets[MaxHeapTuplesPerPage];
 } TBMIterateResult;
 
 /* function prototypes in nodes/tidbitmap.c */
-- 
2.40.1


--w4wcjcocxsm37usi
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v6-0012-Separate-TBM-Shared-Iterator-and-TBMIterateResult.patch"



^ permalink  raw  reply  [nested|flat] 19+ messages in thread

* [PATCH v6 11/14] Hard-code TBMIterateResult offsets array size
@ 2024-02-16 01:13 Melanie Plageman <[email protected]>
  0 siblings, 0 replies; 19+ messages in thread

From: Melanie Plageman @ 2024-02-16 01:13 UTC (permalink / raw)

TIDBitmap's TBMIterateResult had a flexible sized array of tuple offsets
but the API always allocated MaxHeapTuplesPerPage OffsetNumbers.
Creating a fixed-size aray of size MaxHeapTuplesPerPage is more clear
for the API user.
---
 src/backend/nodes/tidbitmap.c | 29 +++++++----------------------
 src/include/nodes/tidbitmap.h | 12 ++++++++++--
 2 files changed, 17 insertions(+), 24 deletions(-)

diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index e8ab5d78fcc..d2bf8f44d50 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -40,7 +40,6 @@
 
 #include <limits.h>
 
-#include "access/htup_details.h"
 #include "common/hashfn.h"
 #include "common/int.h"
 #include "nodes/bitmapset.h"
@@ -48,14 +47,6 @@
 #include "storage/lwlock.h"
 #include "utils/dsa.h"
 
-/*
- * The maximum number of tuples per page is not large (typically 256 with
- * 8K pages, or 1024 with 32K pages).  So there's not much point in making
- * the per-page bitmaps variable size.  We just legislate that the size
- * is this:
- */
-#define MAX_TUPLES_PER_PAGE  MaxHeapTuplesPerPage
-
 /*
  * When we have to switch over to lossy storage, we use a data structure
  * with one bit per page, where all pages having the same number DIV
@@ -67,7 +58,7 @@
  * table, using identical data structures.  (This is because the memory
  * management for hashtables doesn't easily/efficiently allow space to be
  * transferred easily from one hashtable to another.)  Therefore it's best
- * if PAGES_PER_CHUNK is the same as MAX_TUPLES_PER_PAGE, or at least not
+ * if PAGES_PER_CHUNK is the same as MaxHeapTuplesPerPage, or at least not
  * too different.  But we also want PAGES_PER_CHUNK to be a power of 2 to
  * avoid expensive integer remainder operations.  So, define it like this:
  */
@@ -79,7 +70,7 @@
 #define BITNUM(x)	((x) % BITS_PER_BITMAPWORD)
 
 /* number of active words for an exact page: */
-#define WORDS_PER_PAGE	((MAX_TUPLES_PER_PAGE - 1) / BITS_PER_BITMAPWORD + 1)
+#define WORDS_PER_PAGE	((MaxHeapTuplesPerPage - 1) / BITS_PER_BITMAPWORD + 1)
 /* number of active words for a lossy chunk: */
 #define WORDS_PER_CHUNK  ((PAGES_PER_CHUNK - 1) / BITS_PER_BITMAPWORD + 1)
 
@@ -181,7 +172,7 @@ struct TBMIterator
 	int			spageptr;		/* next spages index */
 	int			schunkptr;		/* next schunks index */
 	int			schunkbit;		/* next bit to check in current schunk */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /*
@@ -222,7 +213,7 @@ struct TBMSharedIterator
 	PTEntryArray *ptbase;		/* pagetable element array */
 	PTIterationArray *ptpages;	/* sorted exact page index list */
 	PTIterationArray *ptchunks; /* sorted lossy page index list */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /* Local function prototypes */
@@ -390,7 +381,7 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointer tids, int ntids,
 					bitnum;
 
 		/* safety check to ensure we don't overrun bit array bounds */
-		if (off < 1 || off > MAX_TUPLES_PER_PAGE)
+		if (off < 1 || off > MaxHeapTuplesPerPage)
 			elog(ERROR, "tuple offset out of range: %u", off);
 
 		/*
@@ -692,12 +683,7 @@ tbm_begin_iterate(TIDBitmap *tbm)
 
 	Assert(tbm->iterating != TBM_ITERATING_SHARED);
 
-	/*
-	 * Create the TBMIterator struct, with enough trailing space to serve the
-	 * needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMIterator *) palloc(sizeof(TBMIterator) +
-									  MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = palloc(sizeof(TBMIterator));
 	iterator->tbm = tbm;
 
 	/*
@@ -1467,8 +1453,7 @@ tbm_attach_shared_iterate(dsa_area *dsa, dsa_pointer dp)
 	 * Create the TBMSharedIterator struct, with enough trailing space to
 	 * serve the needs of the TBMIterateResult sub-struct.
 	 */
-	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator) +
-											 MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator));
 
 	istate = (TBMSharedIteratorState *) dsa_get_address(dsa, dp);
 
diff --git a/src/include/nodes/tidbitmap.h b/src/include/nodes/tidbitmap.h
index 1945f0639bf..432fae52962 100644
--- a/src/include/nodes/tidbitmap.h
+++ b/src/include/nodes/tidbitmap.h
@@ -22,6 +22,7 @@
 #ifndef TIDBITMAP_H
 #define TIDBITMAP_H
 
+#include "access/htup_details.h"
 #include "storage/itemptr.h"
 #include "utils/dsa.h"
 
@@ -41,9 +42,16 @@ typedef struct TBMIterateResult
 {
 	BlockNumber blockno;		/* page number containing tuples */
 	int			ntuples;		/* -1 indicates lossy result */
-	bool		recheck;		/* should the tuples be rechecked? */
 	/* Note: recheck is always true if ntuples < 0 */
-	OffsetNumber offsets[FLEXIBLE_ARRAY_MEMBER];
+	bool		recheck;		/* should the tuples be rechecked? */
+
+	/*
+	 * The maximum number of tuples per page is not large (typically 256 with
+	 * 8K pages, or 1024 with 32K pages).  So there's not much point in making
+	 * the per-page bitmaps variable size.  We just legislate that the size is
+	 * this:
+	 */
+	OffsetNumber offsets[MaxHeapTuplesPerPage];
 } TBMIterateResult;
 
 /* function prototypes in nodes/tidbitmap.c */
-- 
2.40.1


--w4wcjcocxsm37usi
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v6-0012-Separate-TBM-Shared-Iterator-and-TBMIterateResult.patch"



^ permalink  raw  reply  [nested|flat] 19+ messages in thread

* [PATCH v10 12/17] Hard-code TBMIterateResult offsets array size
@ 2024-02-16 01:13 Melanie Plageman <[email protected]>
  0 siblings, 0 replies; 19+ messages in thread

From: Melanie Plageman @ 2024-02-16 01:13 UTC (permalink / raw)

TIDBitmap's TBMIterateResult had a flexible sized array of tuple offsets
but the API always allocated MaxHeapTuplesPerPage OffsetNumbers.
Creating a fixed-size aray of size MaxHeapTuplesPerPage is more clear
for the API user.
---
 src/backend/nodes/tidbitmap.c | 33 +++++++--------------------------
 src/include/nodes/tidbitmap.h | 12 ++++++++++--
 2 files changed, 17 insertions(+), 28 deletions(-)

diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index e8ab5d78fc..1dc4c99bf9 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -40,7 +40,6 @@
 
 #include <limits.h>
 
-#include "access/htup_details.h"
 #include "common/hashfn.h"
 #include "common/int.h"
 #include "nodes/bitmapset.h"
@@ -48,14 +47,6 @@
 #include "storage/lwlock.h"
 #include "utils/dsa.h"
 
-/*
- * The maximum number of tuples per page is not large (typically 256 with
- * 8K pages, or 1024 with 32K pages).  So there's not much point in making
- * the per-page bitmaps variable size.  We just legislate that the size
- * is this:
- */
-#define MAX_TUPLES_PER_PAGE  MaxHeapTuplesPerPage
-
 /*
  * When we have to switch over to lossy storage, we use a data structure
  * with one bit per page, where all pages having the same number DIV
@@ -67,7 +58,7 @@
  * table, using identical data structures.  (This is because the memory
  * management for hashtables doesn't easily/efficiently allow space to be
  * transferred easily from one hashtable to another.)  Therefore it's best
- * if PAGES_PER_CHUNK is the same as MAX_TUPLES_PER_PAGE, or at least not
+ * if PAGES_PER_CHUNK is the same as MaxHeapTuplesPerPage, or at least not
  * too different.  But we also want PAGES_PER_CHUNK to be a power of 2 to
  * avoid expensive integer remainder operations.  So, define it like this:
  */
@@ -79,7 +70,7 @@
 #define BITNUM(x)	((x) % BITS_PER_BITMAPWORD)
 
 /* number of active words for an exact page: */
-#define WORDS_PER_PAGE	((MAX_TUPLES_PER_PAGE - 1) / BITS_PER_BITMAPWORD + 1)
+#define WORDS_PER_PAGE	((MaxHeapTuplesPerPage - 1) / BITS_PER_BITMAPWORD + 1)
 /* number of active words for a lossy chunk: */
 #define WORDS_PER_CHUNK  ((PAGES_PER_CHUNK - 1) / BITS_PER_BITMAPWORD + 1)
 
@@ -181,7 +172,7 @@ struct TBMIterator
 	int			spageptr;		/* next spages index */
 	int			schunkptr;		/* next schunks index */
 	int			schunkbit;		/* next bit to check in current schunk */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /*
@@ -222,7 +213,7 @@ struct TBMSharedIterator
 	PTEntryArray *ptbase;		/* pagetable element array */
 	PTIterationArray *ptpages;	/* sorted exact page index list */
 	PTIterationArray *ptchunks; /* sorted lossy page index list */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /* Local function prototypes */
@@ -390,7 +381,7 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointer tids, int ntids,
 					bitnum;
 
 		/* safety check to ensure we don't overrun bit array bounds */
-		if (off < 1 || off > MAX_TUPLES_PER_PAGE)
+		if (off < 1 || off > MaxHeapTuplesPerPage)
 			elog(ERROR, "tuple offset out of range: %u", off);
 
 		/*
@@ -692,12 +683,7 @@ tbm_begin_iterate(TIDBitmap *tbm)
 
 	Assert(tbm->iterating != TBM_ITERATING_SHARED);
 
-	/*
-	 * Create the TBMIterator struct, with enough trailing space to serve the
-	 * needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMIterator *) palloc(sizeof(TBMIterator) +
-									  MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = palloc(sizeof(TBMIterator));
 	iterator->tbm = tbm;
 
 	/*
@@ -1463,12 +1449,7 @@ tbm_attach_shared_iterate(dsa_area *dsa, dsa_pointer dp)
 	TBMSharedIterator *iterator;
 	TBMSharedIteratorState *istate;
 
-	/*
-	 * Create the TBMSharedIterator struct, with enough trailing space to
-	 * serve the needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator) +
-											 MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator));
 
 	istate = (TBMSharedIteratorState *) dsa_get_address(dsa, dp);
 
diff --git a/src/include/nodes/tidbitmap.h b/src/include/nodes/tidbitmap.h
index 1945f0639b..432fae5296 100644
--- a/src/include/nodes/tidbitmap.h
+++ b/src/include/nodes/tidbitmap.h
@@ -22,6 +22,7 @@
 #ifndef TIDBITMAP_H
 #define TIDBITMAP_H
 
+#include "access/htup_details.h"
 #include "storage/itemptr.h"
 #include "utils/dsa.h"
 
@@ -41,9 +42,16 @@ typedef struct TBMIterateResult
 {
 	BlockNumber blockno;		/* page number containing tuples */
 	int			ntuples;		/* -1 indicates lossy result */
-	bool		recheck;		/* should the tuples be rechecked? */
 	/* Note: recheck is always true if ntuples < 0 */
-	OffsetNumber offsets[FLEXIBLE_ARRAY_MEMBER];
+	bool		recheck;		/* should the tuples be rechecked? */
+
+	/*
+	 * The maximum number of tuples per page is not large (typically 256 with
+	 * 8K pages, or 1024 with 32K pages).  So there's not much point in making
+	 * the per-page bitmaps variable size.  We just legislate that the size is
+	 * this:
+	 */
+	OffsetNumber offsets[MaxHeapTuplesPerPage];
 } TBMIterateResult;
 
 /* function prototypes in nodes/tidbitmap.c */
-- 
2.40.1


--3o7pc6dfau5a5hry
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v10-0013-Separate-TBM-Shared-Iterator-and-TBMIterateResul.patch"



^ permalink  raw  reply  [nested|flat] 19+ messages in thread

* [PATCH v8 10/17] Hard-code TBMIterateResult offsets array size
@ 2024-02-16 01:13 Melanie Plageman <[email protected]>
  0 siblings, 0 replies; 19+ messages in thread

From: Melanie Plageman @ 2024-02-16 01:13 UTC (permalink / raw)

TIDBitmap's TBMIterateResult had a flexible sized array of tuple offsets
but the API always allocated MaxHeapTuplesPerPage OffsetNumbers.
Creating a fixed-size aray of size MaxHeapTuplesPerPage is more clear
for the API user.
---
 src/backend/nodes/tidbitmap.c | 33 +++++++--------------------------
 src/include/nodes/tidbitmap.h | 12 ++++++++++--
 2 files changed, 17 insertions(+), 28 deletions(-)

diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index e8ab5d78fc..1dc4c99bf9 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -40,7 +40,6 @@
 
 #include <limits.h>
 
-#include "access/htup_details.h"
 #include "common/hashfn.h"
 #include "common/int.h"
 #include "nodes/bitmapset.h"
@@ -48,14 +47,6 @@
 #include "storage/lwlock.h"
 #include "utils/dsa.h"
 
-/*
- * The maximum number of tuples per page is not large (typically 256 with
- * 8K pages, or 1024 with 32K pages).  So there's not much point in making
- * the per-page bitmaps variable size.  We just legislate that the size
- * is this:
- */
-#define MAX_TUPLES_PER_PAGE  MaxHeapTuplesPerPage
-
 /*
  * When we have to switch over to lossy storage, we use a data structure
  * with one bit per page, where all pages having the same number DIV
@@ -67,7 +58,7 @@
  * table, using identical data structures.  (This is because the memory
  * management for hashtables doesn't easily/efficiently allow space to be
  * transferred easily from one hashtable to another.)  Therefore it's best
- * if PAGES_PER_CHUNK is the same as MAX_TUPLES_PER_PAGE, or at least not
+ * if PAGES_PER_CHUNK is the same as MaxHeapTuplesPerPage, or at least not
  * too different.  But we also want PAGES_PER_CHUNK to be a power of 2 to
  * avoid expensive integer remainder operations.  So, define it like this:
  */
@@ -79,7 +70,7 @@
 #define BITNUM(x)	((x) % BITS_PER_BITMAPWORD)
 
 /* number of active words for an exact page: */
-#define WORDS_PER_PAGE	((MAX_TUPLES_PER_PAGE - 1) / BITS_PER_BITMAPWORD + 1)
+#define WORDS_PER_PAGE	((MaxHeapTuplesPerPage - 1) / BITS_PER_BITMAPWORD + 1)
 /* number of active words for a lossy chunk: */
 #define WORDS_PER_CHUNK  ((PAGES_PER_CHUNK - 1) / BITS_PER_BITMAPWORD + 1)
 
@@ -181,7 +172,7 @@ struct TBMIterator
 	int			spageptr;		/* next spages index */
 	int			schunkptr;		/* next schunks index */
 	int			schunkbit;		/* next bit to check in current schunk */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /*
@@ -222,7 +213,7 @@ struct TBMSharedIterator
 	PTEntryArray *ptbase;		/* pagetable element array */
 	PTIterationArray *ptpages;	/* sorted exact page index list */
 	PTIterationArray *ptchunks; /* sorted lossy page index list */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /* Local function prototypes */
@@ -390,7 +381,7 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointer tids, int ntids,
 					bitnum;
 
 		/* safety check to ensure we don't overrun bit array bounds */
-		if (off < 1 || off > MAX_TUPLES_PER_PAGE)
+		if (off < 1 || off > MaxHeapTuplesPerPage)
 			elog(ERROR, "tuple offset out of range: %u", off);
 
 		/*
@@ -692,12 +683,7 @@ tbm_begin_iterate(TIDBitmap *tbm)
 
 	Assert(tbm->iterating != TBM_ITERATING_SHARED);
 
-	/*
-	 * Create the TBMIterator struct, with enough trailing space to serve the
-	 * needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMIterator *) palloc(sizeof(TBMIterator) +
-									  MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = palloc(sizeof(TBMIterator));
 	iterator->tbm = tbm;
 
 	/*
@@ -1463,12 +1449,7 @@ tbm_attach_shared_iterate(dsa_area *dsa, dsa_pointer dp)
 	TBMSharedIterator *iterator;
 	TBMSharedIteratorState *istate;
 
-	/*
-	 * Create the TBMSharedIterator struct, with enough trailing space to
-	 * serve the needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator) +
-											 MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator));
 
 	istate = (TBMSharedIteratorState *) dsa_get_address(dsa, dp);
 
diff --git a/src/include/nodes/tidbitmap.h b/src/include/nodes/tidbitmap.h
index 1945f0639b..432fae5296 100644
--- a/src/include/nodes/tidbitmap.h
+++ b/src/include/nodes/tidbitmap.h
@@ -22,6 +22,7 @@
 #ifndef TIDBITMAP_H
 #define TIDBITMAP_H
 
+#include "access/htup_details.h"
 #include "storage/itemptr.h"
 #include "utils/dsa.h"
 
@@ -41,9 +42,16 @@ typedef struct TBMIterateResult
 {
 	BlockNumber blockno;		/* page number containing tuples */
 	int			ntuples;		/* -1 indicates lossy result */
-	bool		recheck;		/* should the tuples be rechecked? */
 	/* Note: recheck is always true if ntuples < 0 */
-	OffsetNumber offsets[FLEXIBLE_ARRAY_MEMBER];
+	bool		recheck;		/* should the tuples be rechecked? */
+
+	/*
+	 * The maximum number of tuples per page is not large (typically 256 with
+	 * 8K pages, or 1024 with 32K pages).  So there's not much point in making
+	 * the per-page bitmaps variable size.  We just legislate that the size is
+	 * this:
+	 */
+	OffsetNumber offsets[MaxHeapTuplesPerPage];
 } TBMIterateResult;
 
 /* function prototypes in nodes/tidbitmap.c */
-- 
2.40.1


--xqq4defy3uncu6k6
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v8-0011-table_scan_bitmap_next_block-counts-lossy-and-exa.patch"



^ permalink  raw  reply  [nested|flat] 19+ messages in thread

* [PATCH v9 11/17] Hard-code TBMIterateResult offsets array size
@ 2024-02-16 01:13 Melanie Plageman <[email protected]>
  0 siblings, 0 replies; 19+ messages in thread

From: Melanie Plageman @ 2024-02-16 01:13 UTC (permalink / raw)

TIDBitmap's TBMIterateResult had a flexible sized array of tuple offsets
but the API always allocated MaxHeapTuplesPerPage OffsetNumbers.
Creating a fixed-size aray of size MaxHeapTuplesPerPage is more clear
for the API user.
---
 src/backend/nodes/tidbitmap.c | 33 +++++++--------------------------
 src/include/nodes/tidbitmap.h | 12 ++++++++++--
 2 files changed, 17 insertions(+), 28 deletions(-)

diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index e8ab5d78fc..1dc4c99bf9 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -40,7 +40,6 @@
 
 #include <limits.h>
 
-#include "access/htup_details.h"
 #include "common/hashfn.h"
 #include "common/int.h"
 #include "nodes/bitmapset.h"
@@ -48,14 +47,6 @@
 #include "storage/lwlock.h"
 #include "utils/dsa.h"
 
-/*
- * The maximum number of tuples per page is not large (typically 256 with
- * 8K pages, or 1024 with 32K pages).  So there's not much point in making
- * the per-page bitmaps variable size.  We just legislate that the size
- * is this:
- */
-#define MAX_TUPLES_PER_PAGE  MaxHeapTuplesPerPage
-
 /*
  * When we have to switch over to lossy storage, we use a data structure
  * with one bit per page, where all pages having the same number DIV
@@ -67,7 +58,7 @@
  * table, using identical data structures.  (This is because the memory
  * management for hashtables doesn't easily/efficiently allow space to be
  * transferred easily from one hashtable to another.)  Therefore it's best
- * if PAGES_PER_CHUNK is the same as MAX_TUPLES_PER_PAGE, or at least not
+ * if PAGES_PER_CHUNK is the same as MaxHeapTuplesPerPage, or at least not
  * too different.  But we also want PAGES_PER_CHUNK to be a power of 2 to
  * avoid expensive integer remainder operations.  So, define it like this:
  */
@@ -79,7 +70,7 @@
 #define BITNUM(x)	((x) % BITS_PER_BITMAPWORD)
 
 /* number of active words for an exact page: */
-#define WORDS_PER_PAGE	((MAX_TUPLES_PER_PAGE - 1) / BITS_PER_BITMAPWORD + 1)
+#define WORDS_PER_PAGE	((MaxHeapTuplesPerPage - 1) / BITS_PER_BITMAPWORD + 1)
 /* number of active words for a lossy chunk: */
 #define WORDS_PER_CHUNK  ((PAGES_PER_CHUNK - 1) / BITS_PER_BITMAPWORD + 1)
 
@@ -181,7 +172,7 @@ struct TBMIterator
 	int			spageptr;		/* next spages index */
 	int			schunkptr;		/* next schunks index */
 	int			schunkbit;		/* next bit to check in current schunk */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /*
@@ -222,7 +213,7 @@ struct TBMSharedIterator
 	PTEntryArray *ptbase;		/* pagetable element array */
 	PTIterationArray *ptpages;	/* sorted exact page index list */
 	PTIterationArray *ptchunks; /* sorted lossy page index list */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /* Local function prototypes */
@@ -390,7 +381,7 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointer tids, int ntids,
 					bitnum;
 
 		/* safety check to ensure we don't overrun bit array bounds */
-		if (off < 1 || off > MAX_TUPLES_PER_PAGE)
+		if (off < 1 || off > MaxHeapTuplesPerPage)
 			elog(ERROR, "tuple offset out of range: %u", off);
 
 		/*
@@ -692,12 +683,7 @@ tbm_begin_iterate(TIDBitmap *tbm)
 
 	Assert(tbm->iterating != TBM_ITERATING_SHARED);
 
-	/*
-	 * Create the TBMIterator struct, with enough trailing space to serve the
-	 * needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMIterator *) palloc(sizeof(TBMIterator) +
-									  MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = palloc(sizeof(TBMIterator));
 	iterator->tbm = tbm;
 
 	/*
@@ -1463,12 +1449,7 @@ tbm_attach_shared_iterate(dsa_area *dsa, dsa_pointer dp)
 	TBMSharedIterator *iterator;
 	TBMSharedIteratorState *istate;
 
-	/*
-	 * Create the TBMSharedIterator struct, with enough trailing space to
-	 * serve the needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator) +
-											 MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator));
 
 	istate = (TBMSharedIteratorState *) dsa_get_address(dsa, dp);
 
diff --git a/src/include/nodes/tidbitmap.h b/src/include/nodes/tidbitmap.h
index 1945f0639b..432fae5296 100644
--- a/src/include/nodes/tidbitmap.h
+++ b/src/include/nodes/tidbitmap.h
@@ -22,6 +22,7 @@
 #ifndef TIDBITMAP_H
 #define TIDBITMAP_H
 
+#include "access/htup_details.h"
 #include "storage/itemptr.h"
 #include "utils/dsa.h"
 
@@ -41,9 +42,16 @@ typedef struct TBMIterateResult
 {
 	BlockNumber blockno;		/* page number containing tuples */
 	int			ntuples;		/* -1 indicates lossy result */
-	bool		recheck;		/* should the tuples be rechecked? */
 	/* Note: recheck is always true if ntuples < 0 */
-	OffsetNumber offsets[FLEXIBLE_ARRAY_MEMBER];
+	bool		recheck;		/* should the tuples be rechecked? */
+
+	/*
+	 * The maximum number of tuples per page is not large (typically 256 with
+	 * 8K pages, or 1024 with 32K pages).  So there's not much point in making
+	 * the per-page bitmaps variable size.  We just legislate that the size is
+	 * this:
+	 */
+	OffsetNumber offsets[MaxHeapTuplesPerPage];
 } TBMIterateResult;
 
 /* function prototypes in nodes/tidbitmap.c */
-- 
2.40.1


--7mdtsjmrzitrgzgx
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v9-0012-Separate-TBM-Shared-Iterator-and-TBMIterateResult.patch"



^ permalink  raw  reply  [nested|flat] 19+ messages in thread

* [PATCH v10 12/17] Hard-code TBMIterateResult offsets array size
@ 2024-02-16 01:13 Melanie Plageman <[email protected]>
  0 siblings, 0 replies; 19+ messages in thread

From: Melanie Plageman @ 2024-02-16 01:13 UTC (permalink / raw)

TIDBitmap's TBMIterateResult had a flexible sized array of tuple offsets
but the API always allocated MaxHeapTuplesPerPage OffsetNumbers.
Creating a fixed-size aray of size MaxHeapTuplesPerPage is more clear
for the API user.
---
 src/backend/nodes/tidbitmap.c | 33 +++++++--------------------------
 src/include/nodes/tidbitmap.h | 12 ++++++++++--
 2 files changed, 17 insertions(+), 28 deletions(-)

diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index e8ab5d78fc..1dc4c99bf9 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -40,7 +40,6 @@
 
 #include <limits.h>
 
-#include "access/htup_details.h"
 #include "common/hashfn.h"
 #include "common/int.h"
 #include "nodes/bitmapset.h"
@@ -48,14 +47,6 @@
 #include "storage/lwlock.h"
 #include "utils/dsa.h"
 
-/*
- * The maximum number of tuples per page is not large (typically 256 with
- * 8K pages, or 1024 with 32K pages).  So there's not much point in making
- * the per-page bitmaps variable size.  We just legislate that the size
- * is this:
- */
-#define MAX_TUPLES_PER_PAGE  MaxHeapTuplesPerPage
-
 /*
  * When we have to switch over to lossy storage, we use a data structure
  * with one bit per page, where all pages having the same number DIV
@@ -67,7 +58,7 @@
  * table, using identical data structures.  (This is because the memory
  * management for hashtables doesn't easily/efficiently allow space to be
  * transferred easily from one hashtable to another.)  Therefore it's best
- * if PAGES_PER_CHUNK is the same as MAX_TUPLES_PER_PAGE, or at least not
+ * if PAGES_PER_CHUNK is the same as MaxHeapTuplesPerPage, or at least not
  * too different.  But we also want PAGES_PER_CHUNK to be a power of 2 to
  * avoid expensive integer remainder operations.  So, define it like this:
  */
@@ -79,7 +70,7 @@
 #define BITNUM(x)	((x) % BITS_PER_BITMAPWORD)
 
 /* number of active words for an exact page: */
-#define WORDS_PER_PAGE	((MAX_TUPLES_PER_PAGE - 1) / BITS_PER_BITMAPWORD + 1)
+#define WORDS_PER_PAGE	((MaxHeapTuplesPerPage - 1) / BITS_PER_BITMAPWORD + 1)
 /* number of active words for a lossy chunk: */
 #define WORDS_PER_CHUNK  ((PAGES_PER_CHUNK - 1) / BITS_PER_BITMAPWORD + 1)
 
@@ -181,7 +172,7 @@ struct TBMIterator
 	int			spageptr;		/* next spages index */
 	int			schunkptr;		/* next schunks index */
 	int			schunkbit;		/* next bit to check in current schunk */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /*
@@ -222,7 +213,7 @@ struct TBMSharedIterator
 	PTEntryArray *ptbase;		/* pagetable element array */
 	PTIterationArray *ptpages;	/* sorted exact page index list */
 	PTIterationArray *ptchunks; /* sorted lossy page index list */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /* Local function prototypes */
@@ -390,7 +381,7 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointer tids, int ntids,
 					bitnum;
 
 		/* safety check to ensure we don't overrun bit array bounds */
-		if (off < 1 || off > MAX_TUPLES_PER_PAGE)
+		if (off < 1 || off > MaxHeapTuplesPerPage)
 			elog(ERROR, "tuple offset out of range: %u", off);
 
 		/*
@@ -692,12 +683,7 @@ tbm_begin_iterate(TIDBitmap *tbm)
 
 	Assert(tbm->iterating != TBM_ITERATING_SHARED);
 
-	/*
-	 * Create the TBMIterator struct, with enough trailing space to serve the
-	 * needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMIterator *) palloc(sizeof(TBMIterator) +
-									  MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = palloc(sizeof(TBMIterator));
 	iterator->tbm = tbm;
 
 	/*
@@ -1463,12 +1449,7 @@ tbm_attach_shared_iterate(dsa_area *dsa, dsa_pointer dp)
 	TBMSharedIterator *iterator;
 	TBMSharedIteratorState *istate;
 
-	/*
-	 * Create the TBMSharedIterator struct, with enough trailing space to
-	 * serve the needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator) +
-											 MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator));
 
 	istate = (TBMSharedIteratorState *) dsa_get_address(dsa, dp);
 
diff --git a/src/include/nodes/tidbitmap.h b/src/include/nodes/tidbitmap.h
index 1945f0639b..432fae5296 100644
--- a/src/include/nodes/tidbitmap.h
+++ b/src/include/nodes/tidbitmap.h
@@ -22,6 +22,7 @@
 #ifndef TIDBITMAP_H
 #define TIDBITMAP_H
 
+#include "access/htup_details.h"
 #include "storage/itemptr.h"
 #include "utils/dsa.h"
 
@@ -41,9 +42,16 @@ typedef struct TBMIterateResult
 {
 	BlockNumber blockno;		/* page number containing tuples */
 	int			ntuples;		/* -1 indicates lossy result */
-	bool		recheck;		/* should the tuples be rechecked? */
 	/* Note: recheck is always true if ntuples < 0 */
-	OffsetNumber offsets[FLEXIBLE_ARRAY_MEMBER];
+	bool		recheck;		/* should the tuples be rechecked? */
+
+	/*
+	 * The maximum number of tuples per page is not large (typically 256 with
+	 * 8K pages, or 1024 with 32K pages).  So there's not much point in making
+	 * the per-page bitmaps variable size.  We just legislate that the size is
+	 * this:
+	 */
+	OffsetNumber offsets[MaxHeapTuplesPerPage];
 } TBMIterateResult;
 
 /* function prototypes in nodes/tidbitmap.c */
-- 
2.40.1


--3o7pc6dfau5a5hry
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v10-0013-Separate-TBM-Shared-Iterator-and-TBMIterateResul.patch"



^ permalink  raw  reply  [nested|flat] 19+ messages in thread

* [PATCH v11 12/17] Hard-code TBMIterateResult offsets array size
@ 2024-02-16 01:13 Melanie Plageman <[email protected]>
  0 siblings, 0 replies; 19+ messages in thread

From: Melanie Plageman @ 2024-02-16 01:13 UTC (permalink / raw)

TIDBitmap's TBMIterateResult had a flexible sized array of tuple offsets
but the API always allocated MaxHeapTuplesPerPage OffsetNumbers.
Creating a fixed-size aray of size MaxHeapTuplesPerPage is more clear
for the API user.
---
 src/backend/nodes/tidbitmap.c | 33 +++++++--------------------------
 src/include/nodes/tidbitmap.h | 12 ++++++++++--
 2 files changed, 17 insertions(+), 28 deletions(-)

diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index e8ab5d78fc..1dc4c99bf9 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -40,7 +40,6 @@
 
 #include <limits.h>
 
-#include "access/htup_details.h"
 #include "common/hashfn.h"
 #include "common/int.h"
 #include "nodes/bitmapset.h"
@@ -48,14 +47,6 @@
 #include "storage/lwlock.h"
 #include "utils/dsa.h"
 
-/*
- * The maximum number of tuples per page is not large (typically 256 with
- * 8K pages, or 1024 with 32K pages).  So there's not much point in making
- * the per-page bitmaps variable size.  We just legislate that the size
- * is this:
- */
-#define MAX_TUPLES_PER_PAGE  MaxHeapTuplesPerPage
-
 /*
  * When we have to switch over to lossy storage, we use a data structure
  * with one bit per page, where all pages having the same number DIV
@@ -67,7 +58,7 @@
  * table, using identical data structures.  (This is because the memory
  * management for hashtables doesn't easily/efficiently allow space to be
  * transferred easily from one hashtable to another.)  Therefore it's best
- * if PAGES_PER_CHUNK is the same as MAX_TUPLES_PER_PAGE, or at least not
+ * if PAGES_PER_CHUNK is the same as MaxHeapTuplesPerPage, or at least not
  * too different.  But we also want PAGES_PER_CHUNK to be a power of 2 to
  * avoid expensive integer remainder operations.  So, define it like this:
  */
@@ -79,7 +70,7 @@
 #define BITNUM(x)	((x) % BITS_PER_BITMAPWORD)
 
 /* number of active words for an exact page: */
-#define WORDS_PER_PAGE	((MAX_TUPLES_PER_PAGE - 1) / BITS_PER_BITMAPWORD + 1)
+#define WORDS_PER_PAGE	((MaxHeapTuplesPerPage - 1) / BITS_PER_BITMAPWORD + 1)
 /* number of active words for a lossy chunk: */
 #define WORDS_PER_CHUNK  ((PAGES_PER_CHUNK - 1) / BITS_PER_BITMAPWORD + 1)
 
@@ -181,7 +172,7 @@ struct TBMIterator
 	int			spageptr;		/* next spages index */
 	int			schunkptr;		/* next schunks index */
 	int			schunkbit;		/* next bit to check in current schunk */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /*
@@ -222,7 +213,7 @@ struct TBMSharedIterator
 	PTEntryArray *ptbase;		/* pagetable element array */
 	PTIterationArray *ptpages;	/* sorted exact page index list */
 	PTIterationArray *ptchunks; /* sorted lossy page index list */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /* Local function prototypes */
@@ -390,7 +381,7 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointer tids, int ntids,
 					bitnum;
 
 		/* safety check to ensure we don't overrun bit array bounds */
-		if (off < 1 || off > MAX_TUPLES_PER_PAGE)
+		if (off < 1 || off > MaxHeapTuplesPerPage)
 			elog(ERROR, "tuple offset out of range: %u", off);
 
 		/*
@@ -692,12 +683,7 @@ tbm_begin_iterate(TIDBitmap *tbm)
 
 	Assert(tbm->iterating != TBM_ITERATING_SHARED);
 
-	/*
-	 * Create the TBMIterator struct, with enough trailing space to serve the
-	 * needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMIterator *) palloc(sizeof(TBMIterator) +
-									  MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = palloc(sizeof(TBMIterator));
 	iterator->tbm = tbm;
 
 	/*
@@ -1463,12 +1449,7 @@ tbm_attach_shared_iterate(dsa_area *dsa, dsa_pointer dp)
 	TBMSharedIterator *iterator;
 	TBMSharedIteratorState *istate;
 
-	/*
-	 * Create the TBMSharedIterator struct, with enough trailing space to
-	 * serve the needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator) +
-											 MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator));
 
 	istate = (TBMSharedIteratorState *) dsa_get_address(dsa, dp);
 
diff --git a/src/include/nodes/tidbitmap.h b/src/include/nodes/tidbitmap.h
index 1945f0639b..432fae5296 100644
--- a/src/include/nodes/tidbitmap.h
+++ b/src/include/nodes/tidbitmap.h
@@ -22,6 +22,7 @@
 #ifndef TIDBITMAP_H
 #define TIDBITMAP_H
 
+#include "access/htup_details.h"
 #include "storage/itemptr.h"
 #include "utils/dsa.h"
 
@@ -41,9 +42,16 @@ typedef struct TBMIterateResult
 {
 	BlockNumber blockno;		/* page number containing tuples */
 	int			ntuples;		/* -1 indicates lossy result */
-	bool		recheck;		/* should the tuples be rechecked? */
 	/* Note: recheck is always true if ntuples < 0 */
-	OffsetNumber offsets[FLEXIBLE_ARRAY_MEMBER];
+	bool		recheck;		/* should the tuples be rechecked? */
+
+	/*
+	 * The maximum number of tuples per page is not large (typically 256 with
+	 * 8K pages, or 1024 with 32K pages).  So there's not much point in making
+	 * the per-page bitmaps variable size.  We just legislate that the size is
+	 * this:
+	 */
+	OffsetNumber offsets[MaxHeapTuplesPerPage];
 } TBMIterateResult;
 
 /* function prototypes in nodes/tidbitmap.c */
-- 
2.40.1


--owzzsiozz6hgpp7e
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v11-0013-Separate-TBM-Shared-Iterator-and-TBMIterateResul.patch"



^ permalink  raw  reply  [nested|flat] 19+ messages in thread

* [PATCH v7 10/13] Hard-code TBMIterateResult offsets array size
@ 2024-02-16 01:13 Melanie Plageman <[email protected]>
  0 siblings, 0 replies; 19+ messages in thread

From: Melanie Plageman @ 2024-02-16 01:13 UTC (permalink / raw)

TIDBitmap's TBMIterateResult had a flexible sized array of tuple offsets
but the API always allocated MaxHeapTuplesPerPage OffsetNumbers.
Creating a fixed-size aray of size MaxHeapTuplesPerPage is more clear
for the API user.
---
 src/backend/nodes/tidbitmap.c | 29 +++++++----------------------
 src/include/nodes/tidbitmap.h | 12 ++++++++++--
 2 files changed, 17 insertions(+), 24 deletions(-)

diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index e8ab5d78fcc..d2bf8f44d50 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -40,7 +40,6 @@
 
 #include <limits.h>
 
-#include "access/htup_details.h"
 #include "common/hashfn.h"
 #include "common/int.h"
 #include "nodes/bitmapset.h"
@@ -48,14 +47,6 @@
 #include "storage/lwlock.h"
 #include "utils/dsa.h"
 
-/*
- * The maximum number of tuples per page is not large (typically 256 with
- * 8K pages, or 1024 with 32K pages).  So there's not much point in making
- * the per-page bitmaps variable size.  We just legislate that the size
- * is this:
- */
-#define MAX_TUPLES_PER_PAGE  MaxHeapTuplesPerPage
-
 /*
  * When we have to switch over to lossy storage, we use a data structure
  * with one bit per page, where all pages having the same number DIV
@@ -67,7 +58,7 @@
  * table, using identical data structures.  (This is because the memory
  * management for hashtables doesn't easily/efficiently allow space to be
  * transferred easily from one hashtable to another.)  Therefore it's best
- * if PAGES_PER_CHUNK is the same as MAX_TUPLES_PER_PAGE, or at least not
+ * if PAGES_PER_CHUNK is the same as MaxHeapTuplesPerPage, or at least not
  * too different.  But we also want PAGES_PER_CHUNK to be a power of 2 to
  * avoid expensive integer remainder operations.  So, define it like this:
  */
@@ -79,7 +70,7 @@
 #define BITNUM(x)	((x) % BITS_PER_BITMAPWORD)
 
 /* number of active words for an exact page: */
-#define WORDS_PER_PAGE	((MAX_TUPLES_PER_PAGE - 1) / BITS_PER_BITMAPWORD + 1)
+#define WORDS_PER_PAGE	((MaxHeapTuplesPerPage - 1) / BITS_PER_BITMAPWORD + 1)
 /* number of active words for a lossy chunk: */
 #define WORDS_PER_CHUNK  ((PAGES_PER_CHUNK - 1) / BITS_PER_BITMAPWORD + 1)
 
@@ -181,7 +172,7 @@ struct TBMIterator
 	int			spageptr;		/* next spages index */
 	int			schunkptr;		/* next schunks index */
 	int			schunkbit;		/* next bit to check in current schunk */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /*
@@ -222,7 +213,7 @@ struct TBMSharedIterator
 	PTEntryArray *ptbase;		/* pagetable element array */
 	PTIterationArray *ptpages;	/* sorted exact page index list */
 	PTIterationArray *ptchunks; /* sorted lossy page index list */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /* Local function prototypes */
@@ -390,7 +381,7 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointer tids, int ntids,
 					bitnum;
 
 		/* safety check to ensure we don't overrun bit array bounds */
-		if (off < 1 || off > MAX_TUPLES_PER_PAGE)
+		if (off < 1 || off > MaxHeapTuplesPerPage)
 			elog(ERROR, "tuple offset out of range: %u", off);
 
 		/*
@@ -692,12 +683,7 @@ tbm_begin_iterate(TIDBitmap *tbm)
 
 	Assert(tbm->iterating != TBM_ITERATING_SHARED);
 
-	/*
-	 * Create the TBMIterator struct, with enough trailing space to serve the
-	 * needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMIterator *) palloc(sizeof(TBMIterator) +
-									  MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = palloc(sizeof(TBMIterator));
 	iterator->tbm = tbm;
 
 	/*
@@ -1467,8 +1453,7 @@ tbm_attach_shared_iterate(dsa_area *dsa, dsa_pointer dp)
 	 * Create the TBMSharedIterator struct, with enough trailing space to
 	 * serve the needs of the TBMIterateResult sub-struct.
 	 */
-	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator) +
-											 MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator));
 
 	istate = (TBMSharedIteratorState *) dsa_get_address(dsa, dp);
 
diff --git a/src/include/nodes/tidbitmap.h b/src/include/nodes/tidbitmap.h
index 1945f0639bf..432fae52962 100644
--- a/src/include/nodes/tidbitmap.h
+++ b/src/include/nodes/tidbitmap.h
@@ -22,6 +22,7 @@
 #ifndef TIDBITMAP_H
 #define TIDBITMAP_H
 
+#include "access/htup_details.h"
 #include "storage/itemptr.h"
 #include "utils/dsa.h"
 
@@ -41,9 +42,16 @@ typedef struct TBMIterateResult
 {
 	BlockNumber blockno;		/* page number containing tuples */
 	int			ntuples;		/* -1 indicates lossy result */
-	bool		recheck;		/* should the tuples be rechecked? */
 	/* Note: recheck is always true if ntuples < 0 */
-	OffsetNumber offsets[FLEXIBLE_ARRAY_MEMBER];
+	bool		recheck;		/* should the tuples be rechecked? */
+
+	/*
+	 * The maximum number of tuples per page is not large (typically 256 with
+	 * 8K pages, or 1024 with 32K pages).  So there's not much point in making
+	 * the per-page bitmaps variable size.  We just legislate that the size is
+	 * this:
+	 */
+	OffsetNumber offsets[MaxHeapTuplesPerPage];
 } TBMIterateResult;
 
 /* function prototypes in nodes/tidbitmap.c */
-- 
2.40.1


--kqqpqghcwbcc3dt5
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v7-0011-Separate-TBM-Shared-Iterator-and-TBMIterateResult.patch"



^ permalink  raw  reply  [nested|flat] 19+ messages in thread

* [PATCH v8 10/17] Hard-code TBMIterateResult offsets array size
@ 2024-02-16 01:13 Melanie Plageman <[email protected]>
  0 siblings, 0 replies; 19+ messages in thread

From: Melanie Plageman @ 2024-02-16 01:13 UTC (permalink / raw)

TIDBitmap's TBMIterateResult had a flexible sized array of tuple offsets
but the API always allocated MaxHeapTuplesPerPage OffsetNumbers.
Creating a fixed-size aray of size MaxHeapTuplesPerPage is more clear
for the API user.
---
 src/backend/nodes/tidbitmap.c | 33 +++++++--------------------------
 src/include/nodes/tidbitmap.h | 12 ++++++++++--
 2 files changed, 17 insertions(+), 28 deletions(-)

diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index e8ab5d78fc..1dc4c99bf9 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -40,7 +40,6 @@
 
 #include <limits.h>
 
-#include "access/htup_details.h"
 #include "common/hashfn.h"
 #include "common/int.h"
 #include "nodes/bitmapset.h"
@@ -48,14 +47,6 @@
 #include "storage/lwlock.h"
 #include "utils/dsa.h"
 
-/*
- * The maximum number of tuples per page is not large (typically 256 with
- * 8K pages, or 1024 with 32K pages).  So there's not much point in making
- * the per-page bitmaps variable size.  We just legislate that the size
- * is this:
- */
-#define MAX_TUPLES_PER_PAGE  MaxHeapTuplesPerPage
-
 /*
  * When we have to switch over to lossy storage, we use a data structure
  * with one bit per page, where all pages having the same number DIV
@@ -67,7 +58,7 @@
  * table, using identical data structures.  (This is because the memory
  * management for hashtables doesn't easily/efficiently allow space to be
  * transferred easily from one hashtable to another.)  Therefore it's best
- * if PAGES_PER_CHUNK is the same as MAX_TUPLES_PER_PAGE, or at least not
+ * if PAGES_PER_CHUNK is the same as MaxHeapTuplesPerPage, or at least not
  * too different.  But we also want PAGES_PER_CHUNK to be a power of 2 to
  * avoid expensive integer remainder operations.  So, define it like this:
  */
@@ -79,7 +70,7 @@
 #define BITNUM(x)	((x) % BITS_PER_BITMAPWORD)
 
 /* number of active words for an exact page: */
-#define WORDS_PER_PAGE	((MAX_TUPLES_PER_PAGE - 1) / BITS_PER_BITMAPWORD + 1)
+#define WORDS_PER_PAGE	((MaxHeapTuplesPerPage - 1) / BITS_PER_BITMAPWORD + 1)
 /* number of active words for a lossy chunk: */
 #define WORDS_PER_CHUNK  ((PAGES_PER_CHUNK - 1) / BITS_PER_BITMAPWORD + 1)
 
@@ -181,7 +172,7 @@ struct TBMIterator
 	int			spageptr;		/* next spages index */
 	int			schunkptr;		/* next schunks index */
 	int			schunkbit;		/* next bit to check in current schunk */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /*
@@ -222,7 +213,7 @@ struct TBMSharedIterator
 	PTEntryArray *ptbase;		/* pagetable element array */
 	PTIterationArray *ptpages;	/* sorted exact page index list */
 	PTIterationArray *ptchunks; /* sorted lossy page index list */
-	TBMIterateResult output;	/* MUST BE LAST (because variable-size) */
+	TBMIterateResult output;
 };
 
 /* Local function prototypes */
@@ -390,7 +381,7 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointer tids, int ntids,
 					bitnum;
 
 		/* safety check to ensure we don't overrun bit array bounds */
-		if (off < 1 || off > MAX_TUPLES_PER_PAGE)
+		if (off < 1 || off > MaxHeapTuplesPerPage)
 			elog(ERROR, "tuple offset out of range: %u", off);
 
 		/*
@@ -692,12 +683,7 @@ tbm_begin_iterate(TIDBitmap *tbm)
 
 	Assert(tbm->iterating != TBM_ITERATING_SHARED);
 
-	/*
-	 * Create the TBMIterator struct, with enough trailing space to serve the
-	 * needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMIterator *) palloc(sizeof(TBMIterator) +
-									  MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = palloc(sizeof(TBMIterator));
 	iterator->tbm = tbm;
 
 	/*
@@ -1463,12 +1449,7 @@ tbm_attach_shared_iterate(dsa_area *dsa, dsa_pointer dp)
 	TBMSharedIterator *iterator;
 	TBMSharedIteratorState *istate;
 
-	/*
-	 * Create the TBMSharedIterator struct, with enough trailing space to
-	 * serve the needs of the TBMIterateResult sub-struct.
-	 */
-	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator) +
-											 MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+	iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator));
 
 	istate = (TBMSharedIteratorState *) dsa_get_address(dsa, dp);
 
diff --git a/src/include/nodes/tidbitmap.h b/src/include/nodes/tidbitmap.h
index 1945f0639b..432fae5296 100644
--- a/src/include/nodes/tidbitmap.h
+++ b/src/include/nodes/tidbitmap.h
@@ -22,6 +22,7 @@
 #ifndef TIDBITMAP_H
 #define TIDBITMAP_H
 
+#include "access/htup_details.h"
 #include "storage/itemptr.h"
 #include "utils/dsa.h"
 
@@ -41,9 +42,16 @@ typedef struct TBMIterateResult
 {
 	BlockNumber blockno;		/* page number containing tuples */
 	int			ntuples;		/* -1 indicates lossy result */
-	bool		recheck;		/* should the tuples be rechecked? */
 	/* Note: recheck is always true if ntuples < 0 */
-	OffsetNumber offsets[FLEXIBLE_ARRAY_MEMBER];
+	bool		recheck;		/* should the tuples be rechecked? */
+
+	/*
+	 * The maximum number of tuples per page is not large (typically 256 with
+	 * 8K pages, or 1024 with 32K pages).  So there's not much point in making
+	 * the per-page bitmaps variable size.  We just legislate that the size is
+	 * this:
+	 */
+	OffsetNumber offsets[MaxHeapTuplesPerPage];
 } TBMIterateResult;
 
 /* function prototypes in nodes/tidbitmap.c */
-- 
2.40.1


--xqq4defy3uncu6k6
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v8-0011-table_scan_bitmap_next_block-counts-lossy-and-exa.patch"



^ permalink  raw  reply  [nested|flat] 19+ messages in thread


end of thread, other threads:[~2024-02-16 01:13 UTC | newest]

Thread overview: 19+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2023-02-10 08:27 Re: Inconsistent nullingrels due to oversight in deconstruct_distribute_oj_quals Richard Guo <[email protected]>
2023-02-10 18:40 ` Tom Lane <[email protected]>
2024-02-16 01:13 [PATCH v7 10/13] Hard-code TBMIterateResult offsets array size Melanie Plageman <[email protected]>
2024-02-16 01:13 [PATCH v6 11/14] Hard-code TBMIterateResult offsets array size Melanie Plageman <[email protected]>
2024-02-16 01:13 [PATCH v11 12/17] Hard-code TBMIterateResult offsets array size Melanie Plageman <[email protected]>
2024-02-16 01:13 [PATCH v12 12/17] Hard-code TBMIterateResult offsets array size Melanie Plageman <[email protected]>
2024-02-16 01:13 [PATCH v9 11/17] Hard-code TBMIterateResult offsets array size Melanie Plageman <[email protected]>
2024-02-16 01:13 [PATCH v8 10/17] Hard-code TBMIterateResult offsets array size Melanie Plageman <[email protected]>
2024-02-16 01:13 [PATCH v9 11/17] Hard-code TBMIterateResult offsets array size Melanie Plageman <[email protected]>
2024-02-16 01:13 [PATCH v7 10/13] Hard-code TBMIterateResult offsets array size Melanie Plageman <[email protected]>
2024-02-16 01:13 [PATCH v6 11/14] Hard-code TBMIterateResult offsets array size Melanie Plageman <[email protected]>
2024-02-16 01:13 [PATCH v6 11/14] Hard-code TBMIterateResult offsets array size Melanie Plageman <[email protected]>
2024-02-16 01:13 [PATCH v10 12/17] Hard-code TBMIterateResult offsets array size Melanie Plageman <[email protected]>
2024-02-16 01:13 [PATCH v8 10/17] Hard-code TBMIterateResult offsets array size Melanie Plageman <[email protected]>
2024-02-16 01:13 [PATCH v9 11/17] Hard-code TBMIterateResult offsets array size Melanie Plageman <[email protected]>
2024-02-16 01:13 [PATCH v10 12/17] Hard-code TBMIterateResult offsets array size Melanie Plageman <[email protected]>
2024-02-16 01:13 [PATCH v11 12/17] Hard-code TBMIterateResult offsets array size Melanie Plageman <[email protected]>
2024-02-16 01:13 [PATCH v7 10/13] Hard-code TBMIterateResult offsets array size Melanie Plageman <[email protected]>
2024-02-16 01:13 [PATCH v8 10/17] Hard-code TBMIterateResult offsets array size Melanie Plageman <[email protected]>

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