ITPub博客

首页 > Linux操作系统 > Linux操作系统 > export和import的一点总结

export和import的一点总结

原创 Linux操作系统 作者:等待和希望 时间:2008-05-12 14:35:50 0 删除 编辑
  • 使用sys用户作导出:
    (windows) EXP "'SYS/ORACLE@ORA10G AS SYSDBA"' PARFILE=D:\param.dat
    (unix) exp \'sys/oracle@ora10g as sysdba\' parfile=d:\param.dat
  • 导出大批量数据的时候使用buffer和feedback参数
  • buffer参数:定义export工具每次可取回数据的行数。
    buffer_size = rows_in_array * maximum_row_size
    如果设定buffer=0,则每次取回一条纪录。Tables with columns of type LONG, LOB, BFILE, REF, ROWID, LOGICAL ROWID, or DATE are fetched one row at a time.
    例如表 CREATE TABLE sample (name varchar(30), weight number);
    则 maximum row size=30+2(identifier)+22(number)+2(identifier)
    如导入100行,则buffer=56*100=5600
  • feedback:在导入过程中给与进度提示
  • compress:  Specifies how Export and Import manage the initial extent for table data.
  • The default, COMPRESS=y, causes Export to flag table data for consolidation into one initial extent upon Import. If extent sizes are large (for example, because of the PCTINCREASE parameter), the allocated space will be larger than the space required to hold the data.If you specify COMPRESS=n, Export uses the current storage parameters, including the values of initial extent size and next extent size. The values of the parameters may be the values specified in the CREATE TABLE or ALTER TABLE statements or the values modified by the database system. For example, the NEXT extent size value may be modified if the table grows and if the PCTINCREASE parameter is nonzero.

  • import的表如果包含LOB字段,则尽可能先创建表结构,再进行导入


来自 “ ITPUB博客 ” ,链接:https://blog.itpub.net/55472/viewspace-265164/ ,如需转载,请注明出处,否则将追究法律责任。

下一篇: DMT和LMT
请登录后发表评论 登录
全部评论

注册时间:2008-05-09

  • 博文量
    39
  • 访问量
    93668