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Fix multi WinGetFuncArgInFrame/Partition calls with IGNORE NULLS.

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Previously it was mistakenly assumed that there's only one window
function argument which needs to be processed by WinGetFuncArgInFrame
or WinGetFuncArgInPartition when IGNORE NULLS option is specified. To
eliminate the limitation, WindowObject->notnull_info is modified from
"uint8 *" to "uint8 **" so that WindowObject->notnull_info could store
pointers to "uint8 *" which holds NOT NULL info corresponding to each
window function argument. Moreover, WindowObject->num_notnull_info is
changed from "int" to "int64 *" so that WindowObject->num_notnull_info
could store the number of NOT NULL info corresponding to each function
argument. Memories for these data structures will be allocated when
WinGetFuncArgInFrame or WinGetFuncArgInPartition is called. Thus no
memory except the pointers is allocated for function arguments which
do not call these functions

Also fix the set mark position logic in WinGetFuncArgInPartition to
not raise a "cannot fetch row before WindowObject's mark position"
error in IGNORE NULLS case.

Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Author: Tatsuo Ishii <ishii@postgresql.org>
Discussion: https://postgr.es/m/2952409.1760023154%40sss.pgh.pa.us
This commit is contained in:
Tatsuo Ishii
2025-10-22 12:06:33 +09:00
parent 883a95646a
commit 2d7b247cb4
1 changed files with 98 additions and 38 deletions
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136
src/backend/executor/nodeWindowAgg.c
View File

@@ -69,8 +69,10 @@ typedef struct WindowObjectData
int readptr; /* tuplestore read pointer for this fn */
int64 markpos; /* row that markptr is positioned on */
int64 seekpos; /* row that readptr is positioned on */
uint8 *notnull_info; /* not null info */
int num_notnull_info; /* track size of the notnull_info array */
uint8 **notnull_info; /* not null info for each func args */
int64 *num_notnull_info; /* track size (number of tuples in
* partition) of the notnull_info array
* for each func args */
/*
* Null treatment options. One of: NO_NULLTREATMENT, PARSER_IGNORE_NULLS,
@@ -214,10 +216,14 @@ static Datum ignorenulls_getfuncarginframe(WindowObject winobj, int argno,
static Datum gettuple_eval_partition(WindowObject winobj, int argno,
int64 abs_pos, bool *isnull,
bool *isout);
static void init_notnull_info(WindowObject winobj);
static void grow_notnull_info(WindowObject winobj, int64 pos);
static uint8 get_notnull_info(WindowObject winobj, int64 pos);
static void put_notnull_info(WindowObject winobj, int64 pos, bool isnull);
static void init_notnull_info(WindowObject winobj,
WindowStatePerFunc perfuncstate);
static void grow_notnull_info(WindowObject winobj,
int64 pos, int argno);
static uint8 get_notnull_info(WindowObject winobj,
int64 pos, int argno);
static void put_notnull_info(WindowObject winobj,
int64 pos, int argno, bool isnull);
/*
* Not null info bit array consists of 2-bit items
@@ -1303,10 +1309,20 @@ begin_partition(WindowAggState *winstate)
winobj->seekpos = -1;
/* reset null map */
if (winobj->ignore_nulls == IGNORE_NULLS)
memset(winobj->notnull_info, 0,
NN_POS_TO_BYTES(
perfuncstate->winobj->num_notnull_info));
if (winobj->ignore_nulls == IGNORE_NULLS ||
winobj->ignore_nulls == PARSER_IGNORE_NULLS)
{
int numargs = perfuncstate->numArguments;
for (int j = 0; j < numargs; j++)
{
int n = winobj->num_notnull_info[j];
if (n > 0)
memset(winobj->notnull_info[j], 0,
NN_POS_TO_BYTES(n));
}
}
}
}
@@ -2734,7 +2750,7 @@ ExecInitWindowAgg(WindowAgg *node, EState *estate, int eflags)
winobj->localmem = NULL;
perfuncstate->winobj = winobj;
winobj->ignore_nulls = wfunc->ignore_nulls;
init_notnull_info(winobj);
init_notnull_info(winobj, perfuncstate);
/* It's a real window function, so set up to call it. */
fmgr_info_cxt(wfunc->winfnoid, &perfuncstate->flinfo,
@@ -3387,7 +3403,7 @@ ignorenulls_getfuncarginframe(WindowObject winobj, int argno,
if (isout)
*isout = false;
v = get_notnull_info(winobj, abs_pos);
v = get_notnull_info(winobj, abs_pos, argno);
if (v == NN_NULL) /* this row is known to be NULL */
goto advance;
@@ -3405,7 +3421,7 @@ ignorenulls_getfuncarginframe(WindowObject winobj, int argno,
notnull_offset++;
/* record the row status */
put_notnull_info(winobj, abs_pos, *isnull);
put_notnull_info(winobj, abs_pos, argno, *isnull);
}
else /* this row is known to be NOT NULL */
{
@@ -3445,17 +3461,14 @@ out_of_frame:
* Initialize non null map.
*/
static void
init_notnull_info(WindowObject winobj)
init_notnull_info(WindowObject winobj, WindowStatePerFunc perfuncstate)
{
/* initial number of notnull info members */
#define INIT_NOT_NULL_INFO_NUM 128
int numargs = perfuncstate->numArguments;
if (winobj->ignore_nulls == PARSER_IGNORE_NULLS)
{
Size size = NN_POS_TO_BYTES(INIT_NOT_NULL_INFO_NUM);
winobj->notnull_info = palloc0(size);
winobj->num_notnull_info = INIT_NOT_NULL_INFO_NUM;
winobj->notnull_info = palloc0(sizeof(uint8 *) * numargs);
winobj->num_notnull_info = palloc0(sizeof(int64) * numargs);
}
}
@@ -3463,23 +3476,43 @@ init_notnull_info(WindowObject winobj)
* grow_notnull_info
* expand notnull_info if necessary.
* pos: not null info position
* argno: argument number
*/
static void
grow_notnull_info(WindowObject winobj, int64 pos)
grow_notnull_info(WindowObject winobj, int64 pos, int argno)
{
if (pos >= winobj->num_notnull_info)
/* initial number of notnull info members */
#define INIT_NOT_NULL_INFO_NUM 128
if (pos >= winobj->num_notnull_info[argno])
{
/* We may be called in a short-lived context */
MemoryContext oldcontext = MemoryContextSwitchTo
(winobj->winstate->ss.ps.ps_ExprContext->ecxt_per_query_memory);
for (;;)
{
Size oldsize = NN_POS_TO_BYTES(winobj->num_notnull_info);
Size newsize = oldsize * 2;
Size oldsize = NN_POS_TO_BYTES
(winobj->num_notnull_info[argno]);
Size newsize;
winobj->notnull_info =
repalloc0(winobj->notnull_info, oldsize, newsize);
winobj->num_notnull_info = NN_BYTES_TO_POS(newsize);
if (winobj->num_notnull_info > pos)
if (oldsize == 0) /* memory has not been allocated yet for this
* arg */
{
newsize = NN_POS_TO_BYTES(INIT_NOT_NULL_INFO_NUM);
winobj->notnull_info[argno] = palloc0(newsize);
}
else
{
newsize = oldsize * 2;
winobj->notnull_info[argno] =
repalloc0(winobj->notnull_info[argno], oldsize, newsize);
}
winobj->num_notnull_info[argno] = NN_BYTES_TO_POS(newsize);
if (winobj->num_notnull_info[argno] > pos)
break;
}
MemoryContextSwitchTo(oldcontext);
}
}
@@ -3487,16 +3520,19 @@ grow_notnull_info(WindowObject winobj, int64 pos)
* get_notnull_info
* retrieve a map
* pos: map position
* argno: argument number
*/
static uint8
get_notnull_info(WindowObject winobj, int64 pos)
get_notnull_info(WindowObject winobj, int64 pos, int argno)
{
uint8 *mbp;
uint8 mb;
int64 bpos;
grow_notnull_info(winobj, pos);
grow_notnull_info(winobj, pos, argno);
bpos = NN_POS_TO_BYTES(pos);
mb = winobj->notnull_info[bpos];
mbp = winobj->notnull_info[argno];
mb = mbp[bpos];
return (mb >> (NN_SHIFT(pos))) & NN_MASK;
}
@@ -3504,22 +3540,26 @@ get_notnull_info(WindowObject winobj, int64 pos)
* put_notnull_info
* update map
* pos: map position
* argno: argument number
* isnull: indicate NULL or NOT
*/
static void
put_notnull_info(WindowObject winobj, int64 pos, bool isnull)
put_notnull_info(WindowObject winobj, int64 pos, int argno, bool isnull)
{
uint8 *mbp;
uint8 mb;
int64 bpos;
uint8 val = isnull ? NN_NULL : NN_NOTNULL;
int shift;
grow_notnull_info(winobj, pos);
grow_notnull_info(winobj, pos, argno);
bpos = NN_POS_TO_BYTES(pos);
mb = winobj->notnull_info[bpos];
mbp = winobj->notnull_info[argno];
mb = mbp[bpos];
shift = NN_SHIFT(pos);
mb &= ~(NN_MASK << shift); /* clear map */
mb |= (val << shift); /* update map */
winobj->notnull_info[bpos] = mb;
mbp[bpos] = mb;
}
/***********************************************************************
@@ -3714,6 +3754,7 @@ WinGetFuncArgInPartition(WindowObject winobj, int argno,
{
WindowAggState *winstate;
int64 abs_pos;
int64 mark_pos;
Datum datum;
bool null_treatment;
int notnull_offset;
@@ -3770,6 +3811,25 @@ WinGetFuncArgInPartition(WindowObject winobj, int argno,
myisout = false;
datum = 0;
/*
* IGNORE NULLS + WINDOW_SEEK_CURRENT + relpos > 0 case, we would fetch
* beyond the current row + relpos to find out the target row. If we mark
* at abs_pos, next call to WinGetFuncArgInPartition or
* WinGetFuncArgInFrame (in case when a window function have multiple
* args) could fail with "cannot fetch row before WindowObject's mark
* position". So keep the mark position at currentpos.
*/
if (seektype == WINDOW_SEEK_CURRENT && relpos > 0)
mark_pos = winstate->currentpos;
else
/*
* For other cases we have no idea what position of row callers would
* fetch next time. Also for relpos < 0 case (we go backward), we
* cannot set mark either. For those cases we always set mark at 0.
*/
mark_pos = 0;
/*
* Get the next nonnull value in the partition, moving forward or backward
* until we find a value or reach the partition's end. We cache the
@@ -3784,7 +3844,7 @@ WinGetFuncArgInPartition(WindowObject winobj, int argno,
break;
/* check NOT NULL cached info */
nn_info = get_notnull_info(winobj, abs_pos);
nn_info = get_notnull_info(winobj, abs_pos, argno);
if (nn_info == NN_NOTNULL) /* this row is known to be NOT NULL */
notnull_offset++;
else if (nn_info == NN_NULL) /* this row is known to be NULL */
@@ -3805,7 +3865,7 @@ WinGetFuncArgInPartition(WindowObject winobj, int argno,
if (!*isnull)
notnull_offset++;
/* record the row status */
put_notnull_info(winobj, abs_pos, *isnull);
put_notnull_info(winobj, abs_pos, argno, *isnull);
}
} while (notnull_offset < notnull_relpos);
@@ -3813,7 +3873,7 @@ WinGetFuncArgInPartition(WindowObject winobj, int argno,
datum = gettuple_eval_partition(winobj, argno,
abs_pos, isnull, &myisout);
if (!myisout && set_mark)
WinSetMarkPosition(winobj, abs_pos);
WinSetMarkPosition(winobj, mark_pos);
if (isout)
*isout = myisout;