public ChunkScan(TableInfo ti,long startBlkNum,long endBlkNum,Transaction tx){
  pages=new ArrayList<RecordPage>();
  this.startBlkNum=startBlkNum;
  this.endBlkNum=endBlkNum;
  this.schema=ti.schema();
  this.fileName=ti.fileName();
  for (long i=startBlkNum; i <= endBlkNum; i++) {
    BlockId blk=new BlockId(fileName,i);
    pages.add(new RecordPage(blk,ti,tx,true));
  }
  beforeFirst();
}

public ChunkScan ( TableInfo ti , long startBlkNum , long endBlkNum , Transaction tx ) { pages = new ArrayList < RecordPage > ( ) ; this . startBlkNum = startBlkNum ; this . endBlkNum = endBlkNum ; this . schema = ti . schema ( ) ; this . fileName = ti . fileName ( ) ; for ( long i = startBlkNum ; i <= endBlkNum ; i ++ ) { BlockId blk = new BlockId ( fileName , i ) ; pages . add ( new RecordPage ( blk , ti , tx , true ) ) ; } beforeFirst ( ) ; }
creates a chunk consisting of the specified pages .
