** 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.
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);
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.
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"));
}
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
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.
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);
}
}
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);
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) );
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{
projects / thirdparty / sqlite.git / commitdiff
