SQLite

      n++;
    }
    sqlite3_finalize(pStmt);
  }
  return n==0 ? 0 : (sqlite3_int64)(sum/n);
}



















/*
** Compare the i-th column of pStmt against pValue.  Return true if they
** are different.
*/
static int columnNotEqual(sqlite3_stmt *pStmt, int i, sqlite3_value *pValue){
  int n1, n2, n;
  if( sqlite3_column_type(pStmt,i)!=sqlite3_value_type(pValue) ) return 1;

      return n1!=n2;
 
  }
  return 1;
}

/*
** Stat1 for an index.  Return non-zero if an entry was created.
*/
static int analyzeIndex(const char *zTab, const char *zIdx){
  sqlite3_int64 n = estEntryCount(zIdx);
  sqlite3_stmt *pStmt;
  sqlite3_uint64 *aCnt;
  sqlite3_value **apValue;
  int nCol = 0;
  int nByte;
  int i, j, k;
  int iLimit;
  int nRow = 0;
  char *zRes;
  int szRes;
  int rc;

# define N_SPAN  5
  if( n==0 ) return 0;
  pStmt = db_prepare("PRAGMA index_xinfo=\"%w\"", zIdx);
  while( sqlite3_step(pStmt)==SQLITE_ROW ){
    const char *zColl = (const char*)sqlite3_column_text(pStmt,4);
    if( sqlite3_stricmp(zColl,"binary")!=0 ){
      printf("-- cannot analyze index \"%s\" because column \"%s\" uses"
             " collating sequence \"%s\".\n",
             zIdx, sqlite3_column_text(pStmt, 2), zColl);
      sqlite3_finalize(pStmt);
      return 0;
    }
    if( sqlite3_column_int(pStmt, 5)==0 ) break;
    nCol++;
  }
  sqlite3_finalize(pStmt);
  if( nCol==0 ) return 0;
  nByte = (sizeof(aCnt[0]) + sizeof(apValue[0]))*nCol + 30*(nCol+1);
  aCnt = sqlite3_malloc( nByte );
  if( aCnt==0 ){
    runtimeError("out of memory");
  }
  memset(aCnt, 0, nByte);
  apValue = (sqlite3_value**)&aCnt[nCol];

    pStmt = db_prepare("PRAGMA btree_sample(\"%w\",%g,%lld)",
                       zIdx, ((double)i)/(double)N_SPAN, n*2);
  }  
  for(j=0; j<nCol; j++) sqlite3_value_free(apValue[j]);
  sqlite3_snprintf(szRes, zRes, "%lld", n);
  k = (int)strlen(zRes);
  for(j=0; j<nCol; j++){
    sqlite3_snprintf(szRes-k, zRes+k, " %d", (nRow+aCnt[j]-1)/aCnt[j]);
    k += (int)strlen(zRes+k);
  }
  pStmt = db_prepare(
     "INSERT INTO temp.est_stat1(tbl,idx,stat)"
     "VALUES(\"%w\",\"%w\",'%s')", zTab, zIdx, zRes
  );
  sqlite3_step(pStmt);
  sqlite3_finalize(pStmt);
  return 1;
}

/*
** Stat1 for a table.
*/
static void analyzeTable(const char *zTab){
  sqlite3_int64 n = estEntryCount(zTab);
  sqlite3_stmt *pStmt;
  int nIndex = 0;
  int isWithoutRowid = 0;
  if( n==0 ){
    printf("-- empty table: %s\n", zTab);
    return;
  }
  if( analyzeIndex(zTab,zTab) ){
    isWithoutRowid = 1;
    nIndex++;
  }
  pStmt = db_prepare("PRAGMA index_list(\"%w\")", zTab);
  while( sqlite3_step(pStmt)==SQLITE_ROW ){
    if( sqlite3_column_text(pStmt,3)[0]=='p' && isWithoutRowid ) continue;
    if( sqlite3_column_int(pStmt,4)==0 ) nIndex++;
    analyzeIndex(zTab, (const char*)sqlite3_column_text(pStmt,1));
  }
  sqlite3_finalize(pStmt);
  if( nIndex==0 ){
    pStmt = db_prepare(
       "INSERT INTO temp.est_stat1(tbl,idx,stat)"
       "VALUES(\"%w\",NULL,'%lld')", zTab, n
    );
    sqlite3_step(pStmt);
    sqlite3_finalize(pStmt);
  }
}


/*
** Print the sqlite3_value X as an SQL literal.
*/
static void printQuoted(FILE *out, sqlite3_value *X){
  switch( sqlite3_value_type(X) ){
    case SQLITE_FLOAT: {

    cmdlineError("\"%s\" does not appear to be a valid SQLite database", zDb);
  }
  rc = sqlite3_exec(g.db, "CREATE TEMP TABLE est_stat1(tbl,idx,stat);",
                    0, 0, &zErrMsg);
  if( rc || zErrMsg ){
    cmdlineError("Cannot CREATE TEMP TABLE");
  }
  pStmt = db_prepare("SELECT name FROM sqlite_master"

                     " WHERE type='table' AND rootpage>0"
                     "   AND name NOT LIKE 'sqlite_%%'"
                     " ORDER BY name");
  while( sqlite3_step(pStmt)==SQLITE_ROW ){

    const char *zName = (const char*)sqlite3_column_text(pStmt, 0);


    analyzeTable(zName);



  }
  sqlite3_finalize(pStmt);
  dump_table("temp.est_stat1","sqlite_stat1");
  sqlite3_close(g.db);
  return 0;
}