Oracle Sql 高階程式設計學習過程記錄
sqlplus工具使用:
SQL>help index
@ COPY PAUSE SHUTDOWN
@@ DEFINE PRINT SPOOL
/ DEL PROMPT SQLPLUS
ACCEPT DESCRIBE QUIT START
APPEND DISCONNECT RECOVER STARTUP
ARCHIVE LOG EDIT REMARK STORE
ATTRIBUTE EXECUTE REPFOOTER TIMING
BREAK EXIT REPHEADER TTITLE
BTITLE GET RESERVED WORDS (SQL) UNDEFINE
CHANGE HELP RESERVED WORDS (PL/SQL) VARIABLE
CLEAR HOST RUN WHENEVER OSERROR
COLUMN INPUT SAVE WHENEVER SQLERROR
COMPUTE LIST SET XQUERY
CONNECT PASSWORD SHOW
2016-06-23
程式碼清單3-1
create table scott.t1 as
select trunc((rownum - 1) / 100) id,
rpad(rownum,100) t_pad
from dba_source
where rownum <= 10000;
create index t1_idx1 on t1(id);
exec dbms_stats.gather_table_stats(user,'t1',method_opt=>'FOR ALL COLUMNS SIZE 1',cascade=>true);
drop table t2;
create table scott.t2 as
select mod(rownum,100) id,
rpad(rownum,100) t_pad
from dba_source
where rownum <=10000;
create index t2_idx1 on t2(id);
exec dbms_stats.gather_table_stats(user,'t2',method_opt=>'FOR ALL COLUMNS SIZE 1',cascade=>true);
select count(*) ct from t1 where id = 1 ;
select count(*) ct from t2 where id = 1 ;
select table_name,num_rows,blocks from user_tables where table_name = 'T2';