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Replace variable Index.avgEq (average number of rows in keys for which there is no sample in sqlite_stat4) with vector Index.aAvgEq.

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FossilOrigin-Name: 7b70b419c43b2c3b2daf11d833a1d60245bfaef5
This commit is contained in:
dan
2013-08-07 19:46:15 +00:00
parent 3d40759803
commit eea568d68e
5 changed files with 32 additions and 24 deletions
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18
src/analyze.c
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@@ -327,7 +327,6 @@ static void stat4Push(
){
Stat4Accum *p = (Stat4Accum*)sqlite3_value_blob(argv[0]);
i64 rowid = sqlite3_value_int64(argv[1]);
i64 nSumEq = 0; /* Sum of all nEq parameters */
struct Stat4Sample *pSample;
u32 h;
int iMin = p->iMin;
@@ -1176,14 +1175,15 @@ static int loadStat4(sqlite3 *db, const char *zDb){
pIdx->nSample = nSample;
nByte = sizeof(IndexSample) * nSample;
nByte += sizeof(tRowcnt) * pIdx->nColumn * 3 * nSample;
nByte += pIdx->nColumn * sizeof(tRowcnt); /* Space for Index.aAvgEq[] */
pIdx->aSample = sqlite3DbMallocZero(db, nByte);
pIdx->avgEq = pIdx->aiRowEst[1];
if( pIdx->aSample==0 ){
sqlite3_finalize(pStmt);
return SQLITE_NOMEM;
}
pSpace = (tRowcnt*)&pIdx->aSample[nSample];
pIdx->aAvgEq = pSpace; pSpace += pIdx->nColumn;
for(i=0; i<pIdx->nSample; i++){
pIdx->aSample[i].anEq = pSpace; pSpace += pIdx->nColumn;
pIdx->aSample[i].anLt = pSpace; pSpace += pIdx->nColumn;
@@ -1229,11 +1229,17 @@ static int loadStat4(sqlite3 *db, const char *zDb){
decodeIntArray((char*)sqlite3_column_text(pStmt,3), nCol, pSample->anDLt,0);
if( idx==pIdx->nSample-1 ){
if( pSample->anDLt[0]>0 ){
for(i=0, sumEq=0; i<=idx-1; i++) sumEq += pIdx->aSample[i].anEq[0];
pIdx->avgEq = (pSample->anLt[0] - sumEq)/pSample->anDLt[0];
int iCol;
for(iCol=0; iCol<pIdx->nColumn; iCol++){
tRowcnt avgEq = 0;
tRowcnt nDLt = pSample->anDLt[iCol];
if( nDLt>idx ){
for(i=0, sumEq=0; i<idx; i++) sumEq += pIdx->aSample[i].anEq[iCol];
avgEq = (pSample->anLt[iCol] - sumEq)/(nDLt - idx);
}
if( avgEq==0 ) avgEq = 1;
pIdx->aAvgEq[iCol] = avgEq;
}
if( pIdx->avgEq<=0 ) pIdx->avgEq = 1;
}
pSample->n = sqlite3_column_bytes(pStmt, 4);