Function expertBestIndex

lib-src/sqlite/shell.c:8811–8876

}

static int expertBestIndex(sqlite3_vtab *pVtab, sqlite3_index_info *pIdxInfo){
  ExpertVtab *p = (ExpertVtab*)pVtab;
  int rc = SQLITE_OK;
  int n = 0;
  IdxScan *pScan;
  const int opmask = 
    SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_GT |
    SQLITE_INDEX_CONSTRAINT_LT | SQLITE_INDEX_CONSTRAINT_GE |
    SQLITE_INDEX_CONSTRAINT_LE;

  pScan = idxMalloc(&rc, sizeof(IdxScan));
  if( pScan ){
    int i;

    /* Link the new scan object into the list */
    pScan->pTab = p->pTab;
    pScan->pNextScan = p->pExpert->pScan;
    p->pExpert->pScan = pScan;

    /* Add the constraints to the IdxScan object */
    for(i=0; i<pIdxInfo->nConstraint; i++){
      struct sqlite3_index_constraint *pCons = &pIdxInfo->aConstraint[i];
      if( pCons->usable 
       && pCons->iColumn>=0 
       && p->pTab->aCol[pCons->iColumn].iPk==0
       && (pCons->op & opmask) 
      ){
        IdxConstraint *pNew;
        const char *zColl = sqlite3_vtab_collation(pIdxInfo, i);
        pNew = idxNewConstraint(&rc, zColl);
        if( pNew ){
          pNew->iCol = pCons->iColumn;
          if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ ){
            pNew->pNext = pScan->pEq;
            pScan->pEq = pNew;
          }else{
            pNew->bRange = 1;
            pNew->pNext = pScan->pRange;
            pScan->pRange = pNew;
          }
        }
        n++;
        pIdxInfo->aConstraintUsage[i].argvIndex = n;
      }
    }

    /* Add the ORDER BY to the IdxScan object */
    for(i=pIdxInfo->nOrderBy-1; i>=0; i--){
      int iCol = pIdxInfo->aOrderBy[i].iColumn;
      if( iCol>=0 ){
        IdxConstraint *pNew = idxNewConstraint(&rc, p->pTab->aCol[iCol].zColl);
        if( pNew ){
          pNew->iCol = iCol;
          pNew->bDesc = pIdxInfo->aOrderBy[i].desc;
          pNew->pNext = pScan->pOrder;
          pNew->pLink = pScan->pOrder;
          pScan->pOrder = pNew;
          n++;