SQLite

  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
  int rc = SQLITE_OK;
  int iCol;

  if( pExpr->bDeferred && pExpr->pParent->eType!=FTSQUERY_NEAR ){
    assert( pCsr->nDoc>0 );
    for(iCol=0; iCol<pTab->nColumn; iCol++){
      aiOut[iCol*3 + 1] = (u32)pCsr->nDoc;
      aiOut[iCol*3 + 2] = (u32)pCsr->nDoc;
    }
  }else{
    rc = fts3EvalGatherStats(pCsr, pExpr);
    if( rc==SQLITE_OK ){
      assert( pExpr->aMI );
      for(iCol=0; iCol<pTab->nColumn; iCol++){
        aiOut[iCol*3 + 1] = pExpr->aMI[iCol*3 + 1];

  sqlite3_int64 iPrevId;          /* Previous id read from aDoclist */
  char *pNextId;                  /* Pointer into the body of aDoclist */
  char *aDoclist;                 /* List of docids for full-text queries */
  int nDoclist;                   /* Size of buffer at aDoclist */
  u8 bDesc;                       /* True to sort in descending order */
  int eEvalmode;                  /* An FTS3_EVAL_XX constant */
  int nRowAvg;                    /* Average size of database rows, in pages */
  sqlite3_int64 nDoc;             /* Documents in table */

  int isMatchinfoNeeded;          /* True when aMatchinfo[] needs filling in */
  u32 *aMatchinfo;                /* Information about most recent match */
  int nMatchinfo;                 /* Number of elements in aMatchinfo[] */
  char *zMatchinfo;               /* Matchinfo specification */
};

  assert( pgsz>0 );

  for(ii=0; rc==SQLITE_OK && ii<pMsr->nSegment; ii++){
    Fts3SegReader *pReader = pMsr->apSegment[ii];
    if( !fts3SegReaderIsPending(pReader) 
     && !fts3SegReaderIsRootOnly(pReader) 
    ){
      sqlite3_int64 jj;
      for(jj=pReader->iStartBlock; jj<=pReader->iLeafEndBlock; jj++){
        int nBlob;
        rc = sqlite3Fts3ReadBlock(p, jj, 0, &nBlob, 0);
        if( rc!=SQLITE_OK ) break;
        if( (nBlob+35)>pgsz ){
          nOvfl += (nBlob + 34)/pgsz;
        }

/*
** Return the N-dimensional volumn of the cell stored in *p.
*/
static float cellArea(Rtree *pRtree, RtreeCell *p){
  float area = 1.0;
  int ii;
  for(ii=0; ii<(pRtree->nDim*2); ii+=2){
    area = (float)(area * (DCOORD(p->aCoord[ii+1]) - DCOORD(p->aCoord[ii])));
  }
  return area;
}

/*
** Return the margin length of cell p. The margin length is the sum
** of the objects size in each dimension.
*/
static float cellMargin(Rtree *pRtree, RtreeCell *p){
  float margin = 0.0;
  int ii;
  for(ii=0; ii<(pRtree->nDim*2); ii+=2){
    margin += (float)(DCOORD(p->aCoord[ii+1]) - DCOORD(p->aCoord[ii]));
  }
  return margin;
}

/*
** Store the union of cells p1 and p2 in p1.
*/

        x1 = MAX(DCOORD(p->aCoord[jj]), DCOORD(aCell[ii].aCoord[jj]));
        x2 = MIN(DCOORD(p->aCoord[jj+1]), DCOORD(aCell[ii].aCoord[jj+1]));

        if( x2<x1 ){
          o = 0.0;
          break;
        }else{
          o = o * (float)(x2-x1);
        }
      }
      overlap += o;
    }
  }
  return overlap;
}
#endif

#if VARIANT_RSTARTREE_CHOOSESUBTREE
static float cellOverlapEnlargement(
  Rtree *pRtree, 
  RtreeCell *p, 
  RtreeCell *pInsert, 
  RtreeCell *aCell, 
  int nCell, 
  int iExclude
){
  double before;
  double after;
  before = cellOverlap(pRtree, p, aCell, nCell, iExclude);
  cellUnion(pRtree, p, pInsert);
  after = cellOverlap(pRtree, p, aCell, nCell, iExclude);
  return (float)(after-before);
}
#endif


/*
** This function implements the ChooseLeaf algorithm from Gutman[84].
** ChooseSubTree in r*tree terminology.

    if( ii==(nCell-1) ){
      memcpy(&aCell[ii], pCell, sizeof(RtreeCell));
    }else{
      nodeGetCell(pRtree, pNode, ii, &aCell[ii]);
    }
    aOrder[ii] = ii;
    for(iDim=0; iDim<pRtree->nDim; iDim++){
      aCenterCoord[iDim] += (float)DCOORD(aCell[ii].aCoord[iDim*2]);
      aCenterCoord[iDim] += (float)DCOORD(aCell[ii].aCoord[iDim*2+1]);
    }
  }
  for(iDim=0; iDim<pRtree->nDim; iDim++){
    aCenterCoord[iDim] = (float)(aCenterCoord[iDim]/((float)nCell*2.0));
  }

  for(ii=0; ii<nCell; ii++){
    aDistance[ii] = 0.0;
    for(iDim=0; iDim<pRtree->nDim; iDim++){
      float coord = (float)(DCOORD(aCell[ii].aCoord[iDim*2+1]) - 
          DCOORD(aCell[ii].aCoord[iDim*2]));
      aDistance[ii] += (coord-aCenterCoord[iDim])*(coord-aCenterCoord[iDim]);
    }
  }

  SortByDistance(aOrder, nCell, aDistance, aSpare);
  nodeZero(pRtree, pNode);

    RtreeNode *pInsert;
    RtreeCell cell;
    nodeGetCell(pRtree, pNode, ii, &cell);

    /* Find a node to store this cell in. pNode->iNode currently contains
    ** the height of the sub-tree headed by the cell.
    */
    rc = ChooseLeaf(pRtree, &cell, (int)pNode->iNode, &pInsert);
    if( rc==SQLITE_OK ){
      int rc2;
      rc = rtreeInsertCell(pRtree, pInsert, &cell, (int)pNode->iNode);
      rc2 = nodeRelease(pRtree, pInsert);
      if( rc==SQLITE_OK ){
        rc = rc2;
      }
    }
  }
  return rc;

          int bytes = sqlite3_value_bytes(pIn);
          pVal = Tcl_NewByteArrayObj(sqlite3_value_blob(pIn), bytes);
          break;
        }
        case SQLITE_INTEGER: {
          sqlite_int64 v = sqlite3_value_int64(pIn);
          if( v>=-2147483647 && v<=2147483647 ){
            pVal = Tcl_NewIntObj((int)v);
          }else{
            pVal = Tcl_NewWideIntObj(v);
          }
          break;
        }
        case SQLITE_FLOAT: {
          double r = sqlite3_value_double(pIn);

      const char *zBlob = sqlite3_column_blob(pStmt, iCol);
      if( !zBlob ) bytes = 0;
      return Tcl_NewByteArrayObj((u8*)zBlob, bytes);
    }
    case SQLITE_INTEGER: {
      sqlite_int64 v = sqlite3_column_int64(pStmt, iCol);
      if( v>=-2147483647 && v<=2147483647 ){
        return Tcl_NewIntObj((int)v);
      }else{
        return Tcl_NewWideIntObj(v);
      }
    }
    case SQLITE_FLOAT: {
      return Tcl_NewDoubleObj(sqlite3_column_double(pStmt, iCol));
    }

      int len;
      char *zNull = Tcl_GetStringFromObj(objv[2], &len);
      if( pDb->zNull ){
        Tcl_Free(pDb->zNull);
      }
      if( zNull && len>0 ){
        pDb->zNull = Tcl_Alloc( len + 1 );
        memcpy(pDb->zNull, zNull, len);
        pDb->zNull[len] = '\0';
      }else{
        pDb->zNull = 0;
      }
    }
    Tcl_SetObjResult(interp, dbTextToObj(pDb->zNull));
    break;