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Overview
Comment:Further refinements to the faststat1.c utility.
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SHA1: b051fd19bc5b4e5805154b40beb703674f2a8ba8
User & Date: drh 2016-10-25 19:21:18.947
Context
2016-10-25
19:39
Simplifications to faststat1.c. Fix a bug in sqlite3MovetoProportional() for very large b-trees. (check-in: f7f78147c5 user: drh tags: est_count_pragma)
19:21
Further refinements to the faststat1.c utility. (check-in: b051fd19bc user: drh tags: est_count_pragma)
18:28
Enhance faststat1.c to deal better with WITHOUT ROWID tables. (check-in: 65444f2e35 user: drh tags: est_count_pragma)
Changes
Unified Diff Ignore Whitespace Patch
Changes to tool/faststat1.c.
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  apValue = (sqlite3_value**)&aCnt[nCol];
  zRes = (char*)&apValue[nCol];
  szRes = 30*(nCol+1);

  iLimit = n>10000 ? 100 : 20000;
  pStmt = db_prepare("PRAGMA btree_sample(\"%w\",0.0,%lld)",
                     zIdx, n*2);
  for(i=0; i<N_SPAN; i++){
    k = 0;
    while( k<iLimit && (rc = sqlite3_step(pStmt))==SQLITE_ROW ){
      int iFirst;
      for(iFirst=0; iFirst<nCol; iFirst++){
        if( apValue[iFirst]==0 ) break;
        if( columnNotEqual(pStmt, iFirst, apValue[iFirst]) ) break;
      }
      for(j=iFirst; j<nCol; j++){
        aCnt[j]++;
        sqlite3_value_free(apValue[j]);
        apValue[j] = sqlite3_value_dup(sqlite3_column_value(pStmt,j));
      }



      nRow++;
      k++;
    }
    sqlite3_finalize(pStmt);
    if( rc!=SQLITE_ROW || i==N_SPAN-1 ) break;
    pStmt = db_prepare("PRAGMA btree_sample(\"%w\",%g,%lld)",
                       zIdx, ((double)i)/(double)N_SPAN, n*2);








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  apValue = (sqlite3_value**)&aCnt[nCol];
  zRes = (char*)&apValue[nCol];
  szRes = 30*(nCol+1);

  iLimit = n>10000 ? 100 : 20000;
  pStmt = db_prepare("PRAGMA btree_sample(\"%w\",0.0,%lld)",
                     zIdx, n*2);
  for(i=0; i<=N_SPAN; i++){
    k = 0;
    while( k<iLimit && (rc = sqlite3_step(pStmt))==SQLITE_ROW ){
      int iFirst;
      for(iFirst=0; iFirst<nCol; iFirst++){
        if( apValue[iFirst]==0 ) break;
        if( columnNotEqual(pStmt, iFirst, apValue[iFirst]) ) break;
      }
      for(j=iFirst; j<nCol; j++){
        aCnt[j]++;
        sqlite3_value_free(apValue[j]);
        apValue[j] = sqlite3_value_dup(sqlite3_column_value(pStmt,j));
      }
      if( k==0 && iFirst==nCol ){
        nRow += n/(N_SPAN+1) - iLimit;
      }
      nRow++;
      k++;
    }
    sqlite3_finalize(pStmt);
    if( rc!=SQLITE_ROW || i==N_SPAN-1 ) break;
    pStmt = db_prepare("PRAGMA btree_sample(\"%w\",%g,%lld)",
                       zIdx, ((double)i)/(double)N_SPAN, n*2);
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    }else{
      cmdlineError("unknown argument: %s", argv[i]);
    }
  }
  if( zDb==0 ){
    cmdlineError("database filename required");
  }
  rc = sqlite3_open(zDb, &g.db);
  if( rc ){
    cmdlineError("cannot open database file \"%s\"", zDb);
  }
  rc = sqlite3_exec(g.db, "SELECT * FROM sqlite_master", 0, 0, &zErrMsg);
  if( rc || zErrMsg ){
    cmdlineError("\"%s\" does not appear to be a valid SQLite database", zDb);
  }








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    }else{
      cmdlineError("unknown argument: %s", argv[i]);
    }
  }
  if( zDb==0 ){
    cmdlineError("database filename required");
  }
  rc = sqlite3_open_v2(zDb, &g.db, SQLITE_OPEN_READONLY, 0);
  if( rc ){
    cmdlineError("cannot open database file \"%s\"", zDb);
  }
  rc = sqlite3_exec(g.db, "SELECT * FROM sqlite_master", 0, 0, &zErrMsg);
  if( rc || zErrMsg ){
    cmdlineError("\"%s\" does not appear to be a valid SQLite database", zDb);
  }
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