(11)Managing Table

• Storing User Data
  (1) Regular table
  (2) Partitioned table
  (3) Index-organized table
  (4) Cluster

• ROWID: 18位，64进制的字符串 （内部10bytes，80bit）

  object# 32bits        rfile# 10bits        block# 22bits        row# 16bits

  base 64: A-Z, a-z, 0-9, /,

  SQL> desc dbms_rowid

• Column length: 1或者3 字节

• Creating Temporary Tables
  SQL> create global temporary table xxx 
            on commit delete rows (on commit preserve rows)  as select * from xxx
  DML locks are not acquired
  DMSs don't generate redo logs
  Can create indexes,views and tr