Oracle常用命令大全集（3）

第三章：表

1.create a table

sql> create table table_name (column datatype,column datatype]....)

sql> tablespace tablespace_name [pctfree integer] [pctused integer]

sql> [initrans integer] [maxtrans integer]

sql> storage(initial 200k next 200k pctincrease 0 maxextents 50)

sql> [logging|nologging] [cache|nocache]

2.copy an existing table

sql> create table table_name [logging|nologging] as subquery

3.create temporary table

sql> create global temporary table xay_temp as select * from xay;

on commit preserve rows/on commit delete rows

4.pctfree = (average row size - initial row size) *100 /average row size

pctused = 100-pctfree- (average row size*100/available data space)

5.change storage and block utilization parameter

sql> alter table table_name pctfree=30 pctused=50 storage(next 500k

sql> minextents 2 maxextents 100);

6.manually allocating extents

sql> alter table table_name allocate extent(size 500k datafile 'c:/oracle/data.dbf');

7.move tablespace

sql> alter table employee move tablespace users;

8.deallocate of unused space

sql> alter table table_name deallocate unused [keep integer]

9.truncate a table

sql> truncate table table_name;

10.drop a table

sql> drop table table_name [cascade constraints];

11.drop a column

sql> alter table table_name drop column comments cascade constraints checkpoint 1000;

alter table table_name drop columns continue;

12.mark a column as unused

sql> alter table table_name set unused column comments cascade constraints;

alter table table_name drop unused columns checkpoint 1000;

alter table orders drop columns continue checkpoint 1000

data_dictionary : dba_unused_col_tabs

第四章：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;