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-
sql 代码
- SQL>create table Employee(
- 2 ID VARCHAR2(4 BYTE) NOT NULL,
- 3 First_Name VARCHAR2(10 BYTE),
- 4 Last_Name VARCHAR2(10 BYTE),
- 5 Start_Date DATE,
- 6 End_Date DATE,
- 7 Salary Number(8,2),
- 8 City VARCHAR2(10 BYTE),
- 9 Description VARCHAR2(15 BYTE)
- 10 )
- 11 /
-
- 表已创建。
-
- SQL>insert into Employee(ID, First_Name, Last_Name, Start_Date,
- End_Date, Salary, City, Description)
- 2 values ('01','Jason', 'Martin', to_date('19960725','YY
- YYMMDD'), to_date('20060725','YYYYMMDD'), 1234.56, 'Toronto', 'Programmer')
- 3 /
-
- 已创建 1 行。
-
- SQL>insert into Employee(ID, First_Name, Last_Name, Start_Date,
- End_Date, Salary, City, Description)
- 2 values('02','Alison', 'Mathews', to_date('19760321','YYY
- YMMDD'), to_date('19860221','YYYYMMDD'), 6661.78, 'Vancouver','Tester')
- 3 /
-
- 已创建 1 行。
-
- SQL>select * from Employee
- 2 /
-
- ID FIRST_NAME LAST_NAME START_DATE END_DATE SALARY CITY
-
- DESCRIPTION
-
- 01 Jason Martin 25-7月 -96 25-7月 -06 1234.56 Toronto
- Programmer
-
- 02 Alison Mathews 21-3月 -76 21-2月 -86 6661.78 Vancouver
- Tester
-
-
- SQL>set autotrace on;
- SQL>select count(*) from employee;
-
- COUNT(*)
-
- 2
-
-
- 执行计划
-
- 0 SELECT STATEMENT Optimizer=ALL_ROWS (Cost=2 Card=1)
- 1 0 SORT (AGGREGATE)
- 2 1 TABLE ACCESS (FULL) OF 'EMPLOYEE' (TABLE) (Cost=2 Card=2
- )
-
-
-
-
-
- 统计信息
-
- 5 recursive calls
- 0 db block gets
- 7 consistent gets
- 0 physical reads
- 0 redo size
- 390 bytes sent via SQL*Net to client
- 512 bytes received via SQL*Net from client
- 2 SQL*Net roundtrips to/from client
- 0 sorts (memory)
- 0 sorts (disk)
- 1 rows processed
- SQL>set autotrace off;
- SQL>set autotrace on;
- SQL>set timing on;
- SQL>select count(*) from employee;
-
- COUNT(*)
-
- 2
-
- 已用时间: 00: 00: 00.00
-
- 执行计划
-
- 0 SELECT STATEMENT Optimizer=ALL_ROWS (Cost=2 Card=1)
- 1 0 SORT (AGGREGATE)
- 2 1 TABLE ACCESS (FULL) OF 'EMPLOYEE' (TABLE) (Cost=2 Card=2
- )
-
-
-
-
-
- 统计信息
-
- 0 recursive calls
- 0 db block gets
- 3 consistent gets
- 0 physical reads
- 0 redo size
- 390 bytes sent via SQL*Net to client
- 512 bytes received via SQL*Net from client
- 2 SQL*Net roundtrips to/from client
- 0 sorts (memory)
- 0 sorts (disk)
- 1 rows processed
-
- SQL>set autotrace off;
- SQL>set autotrace traceonly explain
- SQL>select * from employee;
- 已用时间: 00: 00: 00.00
-
- 执行计划
-
- 0 SELECT STATEMENT Optimizer=ALL_ROWS (Cost=2 Card=2 Bytes=130
- )
-
- 1 0 TABLE ACCESS (FULL) OF 'EMPLOYEE' (TABLE) (Cost=2 Card=2 B
- ytes=130)
-
-
-
-
- SQL>analyze table employee compute statistics;
-
- 表已分析。
-
- 已用时间: 00: 00: 00.18
- SQL> select * from employee;
- 已用时间: 00: 00: 00.00
-
- 执行计划
-
- 0 SELECT STATEMENT Optimizer=ALL_ROWS (Cost=2 Card=2 Bytes=98)
- 1 0 TABLE ACCESS (FULL) OF 'EMPLOYEE' (TABLE) (Cost=2 Card=2 B
- ytes=98)
-
-
-
-
- SQL>set autotrace off
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