Oracle常用命令_索引

1.creating function-based indexes
　　sql> create index summit.item_quantity on summit.item(quantity-quantity_shipped);
　　 2.create a B-tree index
　　sql> create [unique] index index_name on table_name(column,.. asc/desc)
　　tablespace
　　sql> tablespace_name [pctfree integer] [initrans integer] [maxtrans integer]
　 　sql> [logging | nologging] [nosort] storage(initial 200k next 200k pctincrease 0
　　sql> maxextents 50);
　　 3.pctfree(index)=(maximum number of rows-initial number of rows)*100/maximum number of rows
　　4.creating reverse key indexes
　 　sql> create unique index xay_id on xay(a) reverse pctfree 30 storage(initial 200k
　　sql> next 200k pctincrease 0 maxextents 50) tablespace indx;
　　5.create bitmap index
　　sql> create bitmap index xay_id on xay(a) pctfree 30 storage( initial 200k next 200k
　　 sql> pctincrease 0 maxextents 50) tablespace indx;
　　6.change storage parameter of index
　　sql> alter index xay_id storage (next 400k maxextents 100);
　　7.allocating index space
　　sql> alter index xay_id allocate extent(size 200k datafile
　　 'c:/oracle/index.dbf');
　　8.alter index xay_id deallocate unused;