From 712ea2507ef7f3ea4a7149962c85de0b35245a64 Mon Sep 17 00:00:00 2001
From: "Vadim B. Mikheev" <vadim4o@yahoo.com>
Date: Thu, 18 Sep 1997 05:37:31 +0000
Subject: [PATCH] 1. Use qsort for first run 2. Limit number of tuples in
leftist trees: - put one tuple from current tree to disk if limit
reached; - end run creation if limit reached by nextrun. 3. Avoid
mergeruns() if first run is single one!
---
src/backend/utils/sort/lselect.c | 15 +-
src/backend/utils/sort/psort.c | 332 ++++++++++++++++++++++++-------
2 files changed, 261 insertions(+), 86 deletions(-)
diff --git a/src/backend/utils/sort/lselect.c b/src/backend/utils/sort/lselect.c
index 1805bd3fd95..ad8fc9764fc 100644
--- a/src/backend/utils/sort/lselect.c
+++ b/src/backend/utils/sort/lselect.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/utils/sort/Attic/lselect.c,v 1.8 1997/09/12 04:08:46 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/sort/Attic/lselect.c,v 1.9 1997/09/18 05:37:30 vadim Exp $
*
*-------------------------------------------------------------------------
*/
@@ -26,15 +26,6 @@
#include "utils/psort.h"
#include "utils/lselect.h"
-#define PUTTUP(TUP, FP) fwrite((char *)TUP, (TUP)->t_len, 1, FP)
-
-/*
- * USEMEM - record use of memory
- * FREEMEM - record freeing of memory
- */
-#define USEMEM(context,AMT) context->sortMem -= (AMT)
-#define FREEMEM(context,AMT) context->sortMem += (AMT)
-
/*
* lmerge - merges two leftist trees into one
*
@@ -149,8 +140,7 @@ gettuple(struct leftist ** treep,
else
*treep = lmerge(tp->lt_left, tp->lt_right, context);
- FREEMEM(context, sizeof(struct leftist));
- FREE(tp);
+ pfree (tp);
return (tup);
}
@@ -173,7 +163,6 @@ puttuple(struct leftist ** treep,
register struct leftist *tp;
new1 = (struct leftist *) palloc((unsigned) sizeof(struct leftist));
- USEMEM(context, sizeof(struct leftist));
new1->lt_dist = 1;
new1->lt_devnum = devnum;
new1->lt_tuple = newtuple;
diff --git a/src/backend/utils/sort/psort.c b/src/backend/utils/sort/psort.c
index c5fab144f01..69485c40b6e 100644
--- a/src/backend/utils/sort/psort.c
+++ b/src/backend/utils/sort/psort.c
@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/utils/sort/Attic/psort.c,v 1.22 1997/09/15 14:28:42 vadim Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/sort/Attic/psort.c,v 1.23 1997/09/18 05:37:31 vadim Exp $
*
* NOTES
* Sorts the first relation into the second relation.
@@ -64,15 +64,17 @@
#include "miscadmin.h"
#include "storage/fd.h"
-static bool createrun(Sort *node, FILE *file, bool *empty);
-static void destroytape(FILE *file);
-static void dumptuples(FILE *file, Sort *node);
+static bool createfirstrun(Sort * node);
+static bool createrun(Sort * node, FILE * file);
+static void destroytape(FILE * file);
+static void dumptuples(FILE * file, Sort * node);
static FILE *gettape(void);
-static void initialrun(Sort *node, bool *empty);
-static void inittapes(Sort *node);
-static void merge(Sort *node, struct tape * dest);
-static FILE *mergeruns(Sort *node);
+static void initialrun(Sort * node);
+static void inittapes(Sort * node);
+static void merge(Sort * node, struct tape * dest);
+static FILE *mergeruns(Sort * node);
static HeapTuple tuplecopy(HeapTuple tup);
+static int _psort_cmp (HeapTuple *ltup, HeapTuple *rtup);
@@ -80,6 +82,10 @@ static HeapTuple tuplecopy(HeapTuple tup);
static long shortzero = 0; /* used to delimit runs */
+static TupleDesc PsortTupDesc;
+static ScanKey PsortKeys; /* used by _psort_cmp */
+static int PsortNkeys;
+
/*
* old psort global variables
*
@@ -123,9 +129,8 @@ static long shortzero = 0; /* used to delimit runs */
* Allocates and initializes sort node's psort state.
*/
bool
-psort_begin(Sort *node, int nkeys, ScanKey key)
+psort_begin(Sort * node, int nkeys, ScanKey key)
{
- bool empty; /* to answer: is child node empty? */
node->psortstate = (struct Psortstate *) palloc(sizeof(struct Psortstate));
@@ -142,17 +147,20 @@ psort_begin(Sort *node, int nkeys, ScanKey key)
PS(node)->treeContext.sortMem = SortMem * 1024;
PS(node)->Tuples = NULL;
+ PS(node)->lasttuple = NULL;
+ PS(node)->lt_tupcount = 0;
PS(node)->tupcount = 0;
PS(node)->using_tape_files = false;
+ PS(node)->psort_grab_file = NULL;
PS(node)->memtuples = NULL;
- initialrun(node, &empty);
+ initialrun(node);
- if (empty)
+ if (PS(node)->tupcount == 0)
return false;
- if (PS(node)->using_tape_files)
+ if (PS(node)->using_tape_files && PS(node)->psort_grab_file == NULL)
PS(node)->psort_grab_file = mergeruns(node);
PS(node)->psort_current = 0;
@@ -168,7 +176,7 @@ psort_begin(Sort *node, int nkeys, ScanKey key)
* number of allocated tapes
*/
static void
-inittapes(Sort *node)
+inittapes(Sort * node)
{
register int i;
register struct tape *tp;
@@ -266,7 +274,7 @@ inittapes(Sort *node)
* Also, perhaps allocate tapes when needed. Split into 2 funcs.
*/
static void
-initialrun(Sort *node, bool *empty)
+initialrun(Sort * node)
{
/* register struct tuple *tup; */
register struct tape *tp;
@@ -278,20 +286,27 @@ initialrun(Sort *node, bool *empty)
tp = PS(node)->Tape;
- if ((bool) createrun(node, NULL, empty) != false)
+ if (createfirstrun(node))
{
- if (!PS(node)->using_tape_files)
- inittapes(node);
+ Assert (PS(node)->using_tape_files);
extrapasses = 0;
}
- else
+ else /* all tuples fetched */
{
- /* if empty or rows fit in memory, we never access tape stuff */
- if (*empty || !PS(node)->using_tape_files)
+ if ( !PS(node)->using_tape_files ) /* empty or sorted in memory */
+ return;
+ /*
+ * if PS(node)->Tuples == NULL then we have single (sorted) run
+ * which can be used as result grab file! So, we may avoid
+ * mergeruns - it will just copy this run to new file.
+ */
+ if ( PS(node)->Tuples == NULL )
+ {
+ PS(node)->psort_grab_file = PS(node)->Tape->tp_file;
+ rewind (PS(node)->psort_grab_file);
return;
- if (!PS(node)->using_tape_files)
- inittapes(node);
- extrapasses = 1 + (PS(node)->Tuples != NULL); /* (T != N) ? 2 : 1 */
+ }
+ extrapasses = 2;
}
for (;;)
@@ -328,7 +343,7 @@ initialrun(Sort *node, bool *empty)
else
break;
- if ((bool) createrun(node, tp->tp_file, empty) == false)
+ if ((bool) createrun(node, tp->tp_file) == false)
extrapasses = 1 + (PS(node)->Tuples != NULL);
/* D2 */
}
@@ -336,6 +351,138 @@ initialrun(Sort *node, bool *empty)
rewind(tp->tp_file); /* D. */
}
+/*
+ * createfirstrun - tries to sort tuples in memory using qsort
+ * until LACKMEM; if not enough memory then switches
+ * to tape method
+ *
+ * Returns:
+ * FALSE iff process through end of relation
+ * Tuples contains the tuples for the following run upon exit
+ */
+static bool
+createfirstrun(Sort *node)
+{
+ HeapTuple tup;
+ bool foundeor = false;
+ HeapTuple *memtuples;
+ int t_last = -1;
+ int t_free = 1000;
+ TupleTableSlot *cr_slot;
+
+ Assert(node != (Sort *) NULL);
+ Assert(PS(node) != (Psortstate *) NULL);
+ Assert(!PS(node)->using_tape_files);
+ Assert(PS(node)->memtuples == NULL);
+ Assert(PS(node)->tupcount == 0);
+ if (LACKMEM(node))
+ elog (FATAL, "psort: LACKMEM in createfirstrun");
+
+ memtuples = palloc(t_free * sizeof(HeapTuple));
+
+ for (;;)
+ {
+ if ( LACKMEM (node) )
+ break;
+
+ /*
+ * About to call ExecProcNode, it can mess up the state if it
+ * eventually calls another Sort node. So must stow it away here
+ * for the meantime. -Rex
+ * 2.2.1995
+ */
+
+ cr_slot = ExecProcNode(outerPlan((Plan *) node), (Plan *) node);
+
+ if (TupIsNull(cr_slot))
+ {
+ foundeor = true;
+ break;
+ }
+
+ tup = tuplecopy(cr_slot->val);
+ ExecClearTuple(cr_slot);
+
+ IncrProcessed();
+ USEMEM(node, tup->t_len);
+ TRACEMEM(createfirstrun);
+ if ( t_free <= 0 )
+ {
+ t_free = 1000;
+ memtuples = repalloc (memtuples,
+ (t_last + t_free + 1) * sizeof (HeapTuple));
+ }
+ t_last++;
+ t_free--;
+ memtuples[t_last] = tup;
+ }
+
+ if ( t_last < 0 ) /* empty */
+ {
+ Assert (foundeor);
+ pfree (memtuples);
+ return (false);
+ }
+ t_last++;
+ PS(node)->tupcount = t_last;
+ PsortTupDesc = PS(node)->treeContext.tupDesc;
+ PsortKeys = PS(node)->treeContext.scanKeys;
+ PsortNkeys = PS(node)->treeContext.nKeys;
+ qsort (memtuples, t_last, sizeof (HeapTuple),
+ (int (*)(const void *,const void *))_psort_cmp);
+
+ if ( LACKMEM (node) ) /* in-memory sort is impossible */
+ {
+ register int t;
+ register int f;
+ FILE *file;
+
+ Assert (!foundeor);
+ inittapes(node);
+ file = PS(node)->Tape->tp_file;
+
+ /* put extra tuples into tape file */
+ if ( t_last > SortTuplesInTree )
+ {
+ register HeapTuple lasttuple;
+
+ t = t_last - SortTuplesInTree;
+ for (f = 0, lasttuple = NULL; f < t; f++)
+ {
+ if ( lasttuple )
+ {
+ FREEMEM(node, lasttuple->t_len);
+ FREE(lasttuple);
+ TRACEMEM(createfirstrun);
+ }
+ lasttuple = memtuples[f];
+ PUTTUP(node, lasttuple, file);
+ TRACEOUT(createfirstrun, lasttuple);
+ }
+ PS(node)->lasttuple = lasttuple;
+ }
+ else
+ {
+ PS(node)->lasttuple = NULL;
+ f = 0;
+ }
+
+ /* put rest of tuples into leftist tree for createrun */
+ for (t = t_last - 1 ; t >= f; t--)
+ puttuple(&PS(node)->Tuples, memtuples[t], 0, &PS(node)->treeContext);
+ PS(node)->lt_tupcount = t_last - f;
+ pfree (memtuples);
+ foundeor = !createrun (node, file);
+ }
+ else
+ {
+ Assert (foundeor);
+ PS(node)->memtuples = memtuples;
+ }
+
+ return (!foundeor);
+}
+
/*
* createrun - places the next run on file, grabbing the tuples by
* executing the subplan passed in
@@ -348,13 +495,15 @@ initialrun(Sort *node, bool *empty)
* Tuples contains the tuples for the following run upon exit
*/
static bool
-createrun(Sort *node, FILE *file, bool *empty)
+createrun(Sort * node, FILE * file)
{
register HeapTuple lasttuple;
register HeapTuple tup;
struct leftist *nextrun;
bool foundeor;
short junk;
+ int curr_tupcount = (PS(node)->Tuples != NULL) ? PS(node)->lt_tupcount : 0;
+ int next_tupcount = 0;
int cr_tuples = 0; /* Count tuples grabbed from plannode */
TupleTableSlot *cr_slot;
@@ -362,33 +511,36 @@ createrun(Sort *node, FILE *file, bool *empty)
Assert(node != (Sort *) NULL);
Assert(PS(node) != (Psortstate *) NULL);
- lasttuple = NULL;
+ lasttuple = PS(node)->lasttuple; /* !NULL if called from createfirstrun */
nextrun = NULL;
foundeor = false;
for (;;)
{
- while (LACKMEM(node) && PS(node)->Tuples != NULL)
+ if ((LACKMEM(node) && PS(node)->Tuples != NULL) || curr_tupcount > SortTuplesInTree)
{
- if (lasttuple != NULL)
- {
- FREEMEM(node, lasttuple->t_len);
- FREE(lasttuple);
- TRACEMEM(createrun);
- }
- lasttuple = tup = gettuple(&PS(node)->Tuples, &junk,
- &PS(node)->treeContext);
- if (!PS(node)->using_tape_files)
+ do
{
- inittapes(node);
- if (!file)
- file = PS(node)->Tape->tp_file; /* was NULL */
- }
- PUTTUP(node, tup, file);
- TRACEOUT(createrun, tup);
+ if (lasttuple != NULL)
+ {
+ FREEMEM(node, lasttuple->t_len);
+ FREE(lasttuple);
+ TRACEMEM(createrun);
+ }
+ lasttuple = tup = gettuple(&PS(node)->Tuples, &junk,
+ &PS(node)->treeContext);
+ Assert (PS(node)->using_tape_files);
+ PUTTUP(node, tup, file);
+ TRACEOUT(createrun, tup);
+ curr_tupcount--;
+ } while (LACKMEM(node) && PS(node)->Tuples != NULL);
}
+
if (LACKMEM(node))
break;
-
+
+ if ( next_tupcount >= SortTuplesInTree )
+ break;
+
/*
* About to call ExecProcNode, it can mess up the state if it
* eventually calls another Sort node. So must stow it away here
@@ -416,9 +568,15 @@ createrun(Sort *node, FILE *file, bool *empty)
TRACEMEM(createrun);
if (lasttuple != NULL && tuplecmp(tup, lasttuple,
&PS(node)->treeContext))
+ {
puttuple(&nextrun, tup, 0, &PS(node)->treeContext);
+ next_tupcount++;
+ }
else
+ {
puttuple(&PS(node)->Tuples, tup, 0, &PS(node)->treeContext);
+ curr_tupcount++;
+ }
}
if (lasttuple != NULL)
{
@@ -427,15 +585,13 @@ createrun(Sort *node, FILE *file, bool *empty)
TRACEMEM(createrun);
}
dumptuples(file, node);
- if (PS(node)->using_tape_files)
- ENDRUN(file);
+ ENDRUN(file);
/* delimit the end of the run */
PS(node)->Tuples = nextrun;
+ PS(node)->lt_tupcount = next_tupcount;
+ PS(node)->lasttuple = NULL;
- /* if we did not see any tuples, mark empty */
- *empty = (cr_tuples > 0) ? false : true;
-
- return ((bool) !foundeor); /* XXX - works iff bool is {0,1} */
+ return ((bool) ! foundeor); /* XXX - works iff bool is {0,1} */
}
/*
@@ -466,7 +622,7 @@ tuplecopy(HeapTuple tup)
* file of tuples in order
*/
static FILE *
-mergeruns(Sort *node)
+mergeruns(Sort * node)
{
register struct tape *tp;
@@ -493,7 +649,7 @@ mergeruns(Sort *node)
* (polyphase merge Alg.D(D5)--Knuth, Vol.3, p271)
*/
static void
-merge(Sort *node, struct tape * dest)
+merge(Sort * node, struct tape * dest)
{
register HeapTuple tup;
register struct tape *lasttp; /* (TAPE[P]) */
@@ -600,20 +756,15 @@ merge(Sort *node, struct tape * dest)
* dumptuples - stores all the tuples in tree into file
*/
static void
-dumptuples(FILE *file, Sort *node)
+dumptuples(FILE * file, Sort * node)
{
register struct leftist *tp;
register struct leftist *newp;
struct leftist **treep = &PS(node)->Tuples;
LeftistContext context = &PS(node)->treeContext;
HeapTuple tup;
- int memtupindex = 0;
- if (!PS(node)->using_tape_files && PS(node)->tupcount)
- {
- Assert(PS(node)->memtuples == NULL);
- PS(node)->memtuples = palloc(PS(node)->tupcount * sizeof(HeapTuple));
- }
+ Assert (PS(node)->using_tape_files);
tp = *treep;
while (tp != NULL)
@@ -625,14 +776,9 @@ dumptuples(FILE *file, Sort *node)
newp = lmerge(tp->lt_left, tp->lt_right, context);
FREEMEM(node, sizeof(struct leftist));
FREE(tp);
- if (PS(node)->using_tape_files)
- {
- PUTTUP(node, tup, file);
- FREEMEM(node, tup->t_len);
- FREE(tup);
- }
- else
- PS(node)->memtuples[memtupindex++] = tup;
+ PUTTUP(node, tup, file);
+ FREEMEM(node, tup->t_len);
+ FREE(tup);
tp = newp;
}
@@ -646,7 +792,7 @@ dumptuples(FILE *file, Sort *node)
* a NULL indicating the last tuple has been processed.
*/
HeapTuple
-psort_grabtuple(Sort *node, bool *should_free)
+psort_grabtuple(Sort * node, bool * should_free)
{
register HeapTuple tup;
long tuplen;
@@ -691,7 +837,7 @@ psort_grabtuple(Sort *node, bool *should_free)
* psort_markpos - saves current position in the merged sort file
*/
void
-psort_markpos(Sort *node)
+psort_markpos(Sort * node)
{
Assert(node != (Sort *) NULL);
Assert(PS(node) != (Psortstate *) NULL);
@@ -704,7 +850,7 @@ psort_markpos(Sort *node)
* last saved position
*/
void
-psort_restorepos(Sort *node)
+psort_restorepos(Sort * node)
{
Assert(node != (Sort *) NULL);
Assert(PS(node) != (Psortstate *) NULL);
@@ -719,13 +865,14 @@ psort_restorepos(Sort *node)
* called unless psort_grabtuple has returned a NULL.
*/
void
-psort_end(Sort *node)
+psort_end(Sort * node)
{
register struct tape *tp;
if (!node->cleaned)
{
Assert(node != (Sort *) NULL);
+
/*
* I'm changing this because if we are sorting a relation with no
* tuples, psortstate is NULL.
@@ -818,7 +965,7 @@ gettape()
*/
#ifdef NOT_USED
static void
-resettape(FILE *file)
+resettape(FILE * file)
{
register struct tapelst *tp;
register int fd;
@@ -850,7 +997,7 @@ resettape(FILE *file)
* Exits instead of returning status, if given invalid tape.
*/
static void
-destroytape(FILE *file)
+destroytape(FILE * file)
{
register struct tapelst *tp,
*tq;
@@ -885,3 +1032,42 @@ destroytape(FILE *file)
tp = tp->tl_next;
}
}
+
+static int
+_psort_cmp (HeapTuple *ltup, HeapTuple *rtup)
+{
+ register Datum lattr, rattr;
+ int nkey = 0;
+ int result = 0;
+ bool isnull1, isnull2;
+
+ while ( nkey < PsortNkeys && !result )
+ {
+ lattr = heap_getattr(*ltup, InvalidBuffer,
+ PsortKeys[nkey].sk_attno,
+ PsortTupDesc,
+ &isnull1);
+ rattr = heap_getattr(*rtup, InvalidBuffer,
+ PsortKeys[nkey].sk_attno,
+ PsortTupDesc,
+ &isnull2);
+ if ( isnull1 )
+ {
+ if ( isnull2 )
+ return (0);
+ return(1);
+ }
+ else if ( isnull2 )
+ return (-1);
+
+ if (PsortKeys[nkey].sk_flags & SK_COMMUTE)
+ {
+ if (!(result = -(long) (*PsortKeys[nkey].sk_func) (rattr, lattr)))
+ result = (long) (*PsortKeys[nkey].sk_func) (lattr, rattr);
+ }
+ else if (!(result = -(long) (*PsortKeys[nkey].sk_func) (lattr, rattr)))
+ result = (long) (*PsortKeys[nkey].sk_func) (rattr, lattr);
+ nkey++;
+ }
+ return (result);
+}
--
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