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The ANALYZE command picks for 15 samples for sqlite_stat3 with the largest

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nEq fields, plus 5 other evenly spaced samples.

FossilOrigin-Name: 8225924ea015a0c331b69134139922ec83f989f8
This commit is contained in:
drh
2011-08-13 00:58:05 +00:00
parent faacf17cc1
commit ade3addfb5
3 changed files with 262 additions and 59 deletions
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15
manifest
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@@ -1,5 +1,5 @@
C Begin\sa\sbranch\sthat\sexperimentally\sreplaces\ssqlite_stat2\swith\sa\snew\stable\ncalled\ssqlite_stat3\sthat\swill\shopefully\sfacilitate\sbetter\squery\nplanning\sdecisions.
D 2011-08-12T01:51:45.485
C The\sANALYZE\scommand\spicks\sfor\s15\ssamples\sfor\ssqlite_stat3\swith\sthe\slargest\nnEq\sfields,\splus\s5\sother\sevenly\sspaced\ssamples.
D 2011-08-13T00:58:05.748
F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
F Makefile.in 1e6988b3c11dee9bd5edc0c804bd4468d74a9cdc
F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -118,7 +118,7 @@ F sqlite.pc.in 42b7bf0d02e08b9e77734a47798d1a55a9e0716b
F sqlite3.1 6be1ad09113570e1fc8dcaff84c9b0b337db5ffc
F sqlite3.pc.in ae6f59a76e862f5c561eb32a380228a02afc3cad
F src/alter.c ac80a0f31189f8b4a524ebf661e47e84536ee7f5
F src/analyze.c da6661dbe12f71d37e81c1138cd7b3175fa60a4f
F src/analyze.c 31a1ea5a5a355097aa7a5fce09bbd9ae2a2c7672
F src/attach.c 12c6957996908edc31c96d7c68d4942c2474405f
F src/auth.c 523da7fb4979469955d822ff9298352d6b31de34
F src/backup.c 986c15232757f2873dff35ee3b35cbf935fc573c
@@ -958,10 +958,7 @@ F tool/symbols.sh caaf6ccc7300fd43353318b44524853e222557d5
F tool/tostr.awk 11760e1b94a5d3dcd42378f3cc18544c06cfa576
F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
F tool/warnings.sh 2ebae31e1eb352696f3c2f7706a34c084b28c262
P 6b236069e1ea3c99ff0a007a790d4baebda70b13
R 28c5bf799a1842cffe08b02c7be0270b
T *branch * stat3-enhancement
T *sym-stat3-enhancement *
T -sym-trunk *
P 52e1d7e8ddd4bb5ef3a9d00fd2d719a8a784f807
R d14fbf4d209dccbd0b61f66b6e37c6c9
U drh
Z 1615a89a47ce6302aa7ba89aa7dcb40d
Z 59baacb653226a018ea530dc8e60b319

2
manifest.uuid
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@@ -1 +1 @@
52e1d7e8ddd4bb5ef3a9d00fd2d719a8a784f807
8225924ea015a0c331b69134139922ec83f989f8

304
src/analyze.c
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@@ -207,9 +207,214 @@ static void openStatTable(
** Recommended number of samples for sqlite_stat3
*/
#ifndef SQLITE_STAT3_SAMPLES
# define SQLITE_STAT3_SAMPLES 16
# define SQLITE_STAT3_SAMPLES 20
#endif
/*
** Three SQL functions - stat3_init(), stat3_push(), and stat3_pop() -
** share an instance of the following structure to hold their state
** information.
*/
typedef struct Stat3Accum Stat3Accum;
struct Stat3Accum {
tRowcnt nRow; /* Number of rows in the entire table */
tRowcnt nPSample; /* How often to do a periodic sample */
int iMin; /* Index of entry with minimum nEq and hash */
int mxSample; /* Maximum number of samples to accumulate */
int nSample; /* Current number of samples */
struct Stat3Sample {
i64 iRowid; /* Rowid in main table of the key */
tRowcnt nEq; /* sqlite_stat3.nEq */
tRowcnt nLt; /* sqlite_stat3.nLt */
u8 isPSample; /* True if a periodic sample */
u32 iHash; /* Tiebreaker hash */
} *a; /* An array of samples */
};
#ifdef SQLITE_ENABLE_STAT3
/*
** Implementation of the stat3_init(C,S) SQL function. The two parameters
** are the number of rows in the table or index (C) and the number of samples
** to accumulate (S).
**
** This routine allocates the Stat3Accum object.
**
** The return value is the Stat3Accum object (P).
*/
static void stat3Init(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
Stat3Accum *p;
tRowcnt nRow;
int mxSample;
int n;
nRow = (tRowcnt)sqlite3_value_int64(argv[0]);
mxSample = sqlite3_value_int(argv[1]);
n = sizeof(*p) + sizeof(p->a[0])*mxSample;
p = sqlite3_malloc( n );
if( p==0 ){
sqlite3_result_error_nomem(context);
return;
}
memset(p, 0, n);
p->a = (struct Stat3Sample*)&p[1];
p->nRow = nRow;
p->mxSample = mxSample;
p->nPSample = p->nRow/6 + 1;
sqlite3_result_blob(context, p, sizeof(p), sqlite3_free);
}
static const FuncDef stat3InitFuncdef = {
2, /* nArg */
SQLITE_UTF8, /* iPrefEnc */
0, /* flags */
0, /* pUserData */
0, /* pNext */
stat3Init, /* xFunc */
0, /* xStep */
0, /* xFinalize */
"stat3_init", /* zName */
0, /* pHash */
0 /* pDestructor */
};
/*
** Implementation of the stat3_push(nEq,nLt,rowid,P) SQL function. The
** arguments describe a single key instance. This routine makes the
** decision about whether or not to retain this key for the sqlite_stat3
** table.
**
** The return value is NULL.
*/
static void stat3Push(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
Stat3Accum *p = (Stat3Accum*)sqlite3_value_blob(argv[3]);
tRowcnt nEq = sqlite3_value_int64(argv[0]);
tRowcnt nLt = sqlite3_value_int64(argv[1]);
i64 rowid = sqlite3_value_int64(argv[2]);
u8 isPSample = 0;
u8 doInsert = 0;
int iMin = p->iMin;
struct Stat3Sample *pSample;
int i;
u32 h, h1, h2, h3;
if( nEq==0 ) return;
h1 = (unsigned)(rowid&0xffff);
h2 = (unsigned)nEq;
h3 = (unsigned)(nLt+1);
h = h1*h2*h3*0x10010001;
if( (nLt/p->nPSample)!=((nEq+nLt)/p->nPSample) ){
doInsert = isPSample = 1;
}else if( p->nSample<p->mxSample ){
doInsert = 1;
}else{
if( nEq>p->a[iMin].nEq || (nEq==p->a[iMin].nEq && h>p->a[iMin].iHash) ){
doInsert = 1;
}
}
if( !doInsert ) return;
if( p->nSample==p->mxSample ){
pSample = &p->a[iMin];
}else{
pSample = &p->a[p->nSample++];
}
pSample->iRowid = rowid;
pSample->nEq = nEq;
pSample->nLt = nLt;
pSample->iHash = h;
pSample->isPSample = isPSample;
/* Find the new minimum */
if( p->nSample==p->mxSample ){
pSample = p->a;
i = 0;
while( pSample->isPSample ){
i++;
pSample++;
assert( i<p->nSample );
}
nEq = pSample->nEq;
h = pSample->iHash;
iMin = i;
for(i++, pSample++; i<p->nSample; i++, pSample++){
if( pSample->isPSample ) continue;
if( pSample->nEq<nEq
|| (pSample->nEq==nEq && pSample->iHash<h)
){
iMin = i;
nEq = pSample->nEq;
h = pSample->iHash;
}
}
p->iMin = iMin;
}
}
static const FuncDef stat3PushFuncdef = {
3, /* nArg */
SQLITE_UTF8, /* iPrefEnc */
0, /* flags */
0, /* pUserData */
0, /* pNext */
stat3Push, /* xFunc */
0, /* xStep */
0, /* xFinalize */
"stat3_push", /* zName */
0, /* pHash */
0 /* pDestructor */
};
/*
** Implementation of the stat3_get(P,N,...) SQL function. This routine is
** used to query the results. Content is returned for the Nth sqlite_stat3
** row where N is between 0 and S-1 and S is the number of samples. The
** value returned depends on the number of arguments.
**
** argc==2 result: rowid
** argc==3 result: nEq
** argc==4 result: nLt
*/
static void stat3Get(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
int n = sqlite3_value_int(argv[1]);
Stat3Accum *p = (Stat3Accum*)sqlite3_value_blob(argv[0]);
assert( p!=0 );
if( p->nSample<=n ) return;
switch( argc ){
case 2: sqlite3_result_int64(context, p->a[n].iRowid); break;
case 3: sqlite3_result_int64(context, p->a[n].nEq); break;
case 4: sqlite3_result_int64(context, p->a[n].nLt); break;
}
}
static const FuncDef stat3GetFuncdef = {
-1, /* nArg */
SQLITE_UTF8, /* iPrefEnc */
0, /* flags */
0, /* pUserData */
0, /* pNext */
stat3Get, /* xFunc */
0, /* xStep */
0, /* xFinalize */
"stat3_get", /* zName */
0, /* pHash */
0 /* pDestructor */
};
#endif /* SQLITE_ENABLE_STAT3 */
/*
** Generate code to do an analysis of all indices associated with
** a single table.
@@ -234,23 +439,23 @@ static void analyzeOneTable(
int regIdxname = iMem++; /* Register containing index name */
int regStat1 = iMem++; /* The stat column of sqlite_stat1 */
#ifdef SQLITE_ENABLE_STAT3
int regNumEq = iMem-1; /* Number of instances. Same as regStat1 */
int regNumEq = regStat1; /* Number of instances. Same as regStat1 */
int regNumLt = iMem++; /* Number of keys less than regSample */
int regSample = iMem++; /* The next sample value */
int regNext = iMem++; /* Index of next sample to record */
int regSpacing = iMem++; /* Spacing between samples */
int regBigSize = iMem++; /* Always save entries with nEq >= this */
int regTemp1 = iMem++; /* Intermediate register */
int regRowid = regSample; /* Rowid of a sample */
int regAccum = iMem++; /* Register to hold Stat3Accum object */
int regLoop = iMem++; /* Loop counter */
int regCount = iMem++; /* Number of rows in the table or index */
int regGosub = iMem++; /* Register holding subroutine return addr */
int regTemp1 = iMem++; /* Intermediate register */
int regTemp2 = iMem++; /* Intermediate register */
int once = 1; /* One-time initialization */
int shortJump = 0; /* Instruction address */
int addrStoreStat3 = 0; /* Address of subroutine to wrote to stat3 */
int iTabCur = pParse->nTab++; /* Table cursor */
#endif
int regCol = iMem++; /* Content of a column in analyzed table */
int regRec = iMem++; /* Register holding completed record */
int regTemp = iMem++; /* Temporary use register */
int regRowid = iMem++; /* Rowid for the inserted record */
int regNewRowid = iMem++; /* Rowid for the inserted record */
v = sqlite3GetVdbe(pParse);
@@ -307,41 +512,17 @@ static void analyzeOneTable(
sqlite3VdbeAddOp4(v, OP_String8, 0, regIdxname, 0, pIdx->zName, 0);
#ifdef SQLITE_ENABLE_STAT3
/* If this iteration of the loop is generating code to analyze the
** first index in the pTab->pIndex list, then register regLast has
** not been populated. In this case populate it now. */
if( once ){
once = 0;
sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regCount);
sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_STAT3_SAMPLES, regTemp1);
sqlite3VdbeAddOp3(v, OP_Divide, regTemp1, regCount, regSpacing);
sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_STAT3_SAMPLES/2, regTemp1);
sqlite3VdbeAddOp3(v, OP_Divide, regTemp1, regCount, regBigSize);
/* Generate code for a subroutine that store the most recent sample
** in the sqlite_stat3 table
*/
shortJump = sqlite3VdbeAddOp0(v, OP_Goto);
sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 5, regRec, "bbbbb", 0);
VdbeComment((v, "begin stat3 write subroutine"));
sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur+1, regRowid);
sqlite3VdbeAddOp3(v, OP_Insert, iStatCur+1, regRec, regRowid);
sqlite3VdbeAddOp3(v, OP_Add, regNext, regSpacing, regNext);
sqlite3VdbeAddOp1(v, OP_Return, regGosub);
addrStoreStat3 =
sqlite3VdbeAddOp3(v, OP_Ge, regBigSize, shortJump+1, regNumEq);
sqlite3VdbeAddOp3(v, OP_Add, regNumEq, regNumLt, regTemp1);
sqlite3VdbeAddOp3(v, OP_Ge, regNext, shortJump+1, regTemp1);
sqlite3VdbeAddOp1(v, OP_Return, regGosub);
VdbeComment((v, "end stat3 write subroutine"));
sqlite3VdbeJumpHere(v, shortJump);
sqlite3OpenTable(pParse, iTabCur, iDb, pTab, OP_OpenRead);
}
/* Reset state registers */
sqlite3VdbeAddOp2(v, OP_Copy, regSpacing, regNext);
sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regCount);
sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_STAT3_SAMPLES, regTemp1);
sqlite3VdbeAddOp2(v, OP_Integer, 0, regNumEq);
sqlite3VdbeAddOp2(v, OP_Integer, 0, regNumLt);
sqlite3VdbeAddOp4(v, OP_Function, 1, regCount, regAccum,
(char*)&stat3InitFuncdef, P4_FUNCDEF);
sqlite3VdbeChangeP5(v, 2);
#endif /* SQLITE_ENABLE_STAT3 */
/* The block of memory cells initialized here is used as follows.
@@ -389,7 +570,7 @@ static void analyzeOneTable(
sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);
VdbeComment((v, "jump if column %d changed", i));
#ifdef SQLITE_ENABLE_STAT3
if( i==0 && addrStoreStat3 ){
if( i==0 ){
sqlite3VdbeAddOp2(v, OP_AddImm, regNumEq, 1);
VdbeComment((v, "incr repeat count"));
}
@@ -401,8 +582,10 @@ static void analyzeOneTable(
if( i==0 ){
sqlite3VdbeJumpHere(v, addrIfNot); /* Jump dest for OP_IfNot */
#ifdef SQLITE_ENABLE_STAT3
sqlite3VdbeAddOp2(v, OP_Gosub, regGosub, addrStoreStat3);
sqlite3VdbeAddOp2(v, OP_Copy, regCol, regSample);
sqlite3VdbeAddOp4(v, OP_Function, 1, regNumEq, regTemp2,
(char*)&stat3PushFuncdef, P4_FUNCDEF);
sqlite3VdbeChangeP5(v, 4);
sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, pIdx->nColumn, regRowid);
sqlite3VdbeAddOp3(v, OP_Add, regNumEq, regNumLt, regNumLt);
sqlite3VdbeAddOp2(v, OP_Integer, 1, regNumEq);
#endif
@@ -418,7 +601,30 @@ static void analyzeOneTable(
sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, topOfLoop);
sqlite3VdbeAddOp1(v, OP_Close, iIdxCur);
#ifdef SQLITE_ENABLE_STAT3
sqlite3VdbeAddOp2(v, OP_Gosub, regGosub, addrStoreStat3);
sqlite3VdbeAddOp4(v, OP_Function, 1, regNumEq, regTemp2,
(char*)&stat3PushFuncdef, P4_FUNCDEF);
sqlite3VdbeChangeP5(v, 4);
sqlite3VdbeAddOp2(v, OP_Integer, -1, regLoop);
shortJump =
sqlite3VdbeAddOp2(v, OP_AddImm, regLoop, 1);
sqlite3VdbeAddOp4(v, OP_Function, 1, regAccum, regTemp1,
(char*)&stat3GetFuncdef, P4_FUNCDEF);
sqlite3VdbeChangeP5(v, 2);
sqlite3VdbeAddOp1(v, OP_IsNull, regTemp1);
sqlite3VdbeAddOp3(v, OP_NotExists, iTabCur, shortJump, regTemp1);
sqlite3VdbeAddOp3(v, OP_Column, iTabCur, pIdx->aiColumn[0], regSample);
sqlite3ColumnDefault(v, pTab, pIdx->aiColumn[0], regSample);
sqlite3VdbeAddOp4(v, OP_Function, 1, regAccum, regNumEq,
(char*)&stat3GetFuncdef, P4_FUNCDEF);
sqlite3VdbeChangeP5(v, 3);
sqlite3VdbeAddOp4(v, OP_Function, 1, regAccum, regNumLt,
(char*)&stat3GetFuncdef, P4_FUNCDEF);
sqlite3VdbeChangeP5(v, 4);
sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 5, regRec, "bbbbb", 0);
sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur+1, regNewRowid);
sqlite3VdbeAddOp3(v, OP_Insert, iStatCur+1, regRec, regNewRowid);
sqlite3VdbeAddOp2(v, OP_Goto, 0, shortJump);
sqlite3VdbeJumpHere(v, shortJump+2);
#endif
/* Store the results in sqlite_stat1.
@@ -453,8 +659,8 @@ static void analyzeOneTable(
sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regStat1, regStat1);
}
sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0);
sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regRowid);
sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regRowid);
sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid);
sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regNewRowid);
sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
}
@@ -473,8 +679,8 @@ static void analyzeOneTable(
}
sqlite3VdbeAddOp2(v, OP_Null, 0, regIdxname);
sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0);
sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regRowid);
sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regRowid);
sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid);
sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regNewRowid);
sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
if( pParse->nMem<regRec ) pParse->nMem = regRec;
sqlite3VdbeJumpHere(v, jZeroRows);
@@ -504,7 +710,7 @@ static void analyzeDatabase(Parse *pParse, int iDb){
sqlite3BeginWriteOperation(pParse, 0, iDb);
iStatCur = pParse->nTab;
pParse->nTab += 2;
pParse->nTab += 3;
openStatTable(pParse, iDb, iStatCur, 0, 0);
iMem = pParse->nMem+1;
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
@@ -529,7 +735,7 @@ static void analyzeTable(Parse *pParse, Table *pTab, Index *pOnlyIdx){
iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
sqlite3BeginWriteOperation(pParse, 0, iDb);
iStatCur = pParse->nTab;
pParse->nTab += 2;
pParse->nTab += 3;
if( pOnlyIdx ){
openStatTable(pParse, iDb, iStatCur, pOnlyIdx->zName, "idx");
}else{