我做的程序一开始,没有创建plan_table表 但是当过一段时间的时候发现 数据库中突然出现了plan_table表,怀疑是系统自动生成的,但是不知道为什么生成plan_table这个表,plan_table这个表又是干什么用的呢?=======================
这个表的具体字段是
=======================
=====================================================================================
-- Create table
create table PLAN_TABLE
(
STATEMENT_ID VARCHAR2(30),
PLAN_ID NUMBER,
TIMESTAMP DATE,
REMARKS VARCHAR2(4000),
OPERATION VARCHAR2(30),
OPTIONS VARCHAR2(255),
OBJECT_NODE VARCHAR2(128),
OBJECT_OWNER VARCHAR2(30),
OBJECT_NAME VARCHAR2(30),
OBJECT_ALIAS VARCHAR2(65),
OBJECT_INSTANCE INTEGER,
OBJECT_TYPE VARCHAR2(30),
OPTIMIZER VARCHAR2(255),
SEARCH_COLUMNS NUMBER,
ID INTEGER,
PARENT_ID INTEGER,
DEPTH INTEGER,
POSITION INTEGER,
COST INTEGER,
CARDINALITY INTEGER,
BYTES INTEGER,
OTHER_TAG VARCHAR2(255),
PARTITION_START VARCHAR2(255),
PARTITION_STOP VARCHAR2(255),
PARTITION_ID INTEGER,
OTHER LONG,
DISTRIBUTION VARCHAR2(30),
CPU_COST INTEGER,
IO_COST INTEGER,
TEMP_SPACE INTEGER,
ACCESS_PREDICATES VARCHAR2(4000),
FILTER_PREDICATES VARCHAR2(4000),
PROJECTION VARCHAR2(4000),
TIME INTEGER,
QBLOCK_NAME VARCHAR2(30)
)
tablespace CRM
pctfree 10
initrans 1
maxtrans 255
storage
(
initial 64K
minextents 1
maxextents unlimited
);
这个表的具体字段是
=======================
=====================================================================================
-- Create table
create table PLAN_TABLE
(
STATEMENT_ID VARCHAR2(30),
PLAN_ID NUMBER,
TIMESTAMP DATE,
REMARKS VARCHAR2(4000),
OPERATION VARCHAR2(30),
OPTIONS VARCHAR2(255),
OBJECT_NODE VARCHAR2(128),
OBJECT_OWNER VARCHAR2(30),
OBJECT_NAME VARCHAR2(30),
OBJECT_ALIAS VARCHAR2(65),
OBJECT_INSTANCE INTEGER,
OBJECT_TYPE VARCHAR2(30),
OPTIMIZER VARCHAR2(255),
SEARCH_COLUMNS NUMBER,
ID INTEGER,
PARENT_ID INTEGER,
DEPTH INTEGER,
POSITION INTEGER,
COST INTEGER,
CARDINALITY INTEGER,
BYTES INTEGER,
OTHER_TAG VARCHAR2(255),
PARTITION_START VARCHAR2(255),
PARTITION_STOP VARCHAR2(255),
PARTITION_ID INTEGER,
OTHER LONG,
DISTRIBUTION VARCHAR2(30),
CPU_COST INTEGER,
IO_COST INTEGER,
TEMP_SPACE INTEGER,
ACCESS_PREDICATES VARCHAR2(4000),
FILTER_PREDICATES VARCHAR2(4000),
PROJECTION VARCHAR2(4000),
TIME INTEGER,
QBLOCK_NAME VARCHAR2(30)
)
tablespace CRM
pctfree 10
initrans 1
maxtrans 255
storage
(
initial 64K
minextents 1
maxextents unlimited
);
PLAN_TABLE is the default table for results of the EXPLAIN PLAN statement. It is created by utlxplan.sql, and it contains one row for each step in the execution plan.
当你使用EXPLAIN PLAN 时生成。