Apress.Expert.Oracle.Database.Architecture.9i.and.10g.Programming.Techniques.and.Solutions.Sep.2005

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CHAPTER 10 ■ DATABASE TABLES
[tkyte@localhost tkyte]$ imp userid=/ indexfile=people.sql full=y
Import: Release 10.1.0.3.0 - Production on Sun May 1 14:04:33 2005
Copyright (c) 1982, 2004, Oracle. All rights reserved.
Connected to: Oracle Database 10g Enterprise Edition Release 10.1.0.3.0 - Production
With the Partitioning, OLAP and Data Mining options
Export file created by EXPORT:V10.01.00 via conventional path
import done in WE8ISO8859P1 character set and AL16UTF16 NCHAR character set
Import terminated successfully without warnings.
Review of the people.sql file that results would show this:
CREATE TABLE "OPS$TKYTE"."PEOPLE"
OF "PERSON_TYPE" OID 'F610318AC3D8981FE030007F01001464'
OIDINDEX (PCTFREE 10 INITRANS 2 MAXTRANS 255
STORAGE(INITIAL 131072 NEXT 131072
MINEXTENTS 1 MAXEXTENTS 4096
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
BUFFER_POOL DEFAULT)
TABLESPACE "USERS")
PCTFREE 10 PCTUSED 40
INITRANS 1 MAXTRANS 255
LOGGING STORAGE(INITIAL 131072 NEXT 131072
MINEXTENTS 1 MAXEXTENTS 4096
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
BUFFER_POOL DEFAULT) TABLESPACE "USERS" NOCOMPRESS
/
ALTER TABLE "OPS$TKYTE"."PEOPLE" MODIFY
("SYS_NC_OID$" DEFAULT SYS_OP_GUID())
/
This gives us a little more insight into what is actually taking place here. We see the
OIDINDEX clause clearly now, and we see a reference to the SYS_NC_OID$ column. This is the hidden
primary key of the table. The function SYS_OP_GUID is the same as the function SYS_GUID.
They both return a globally unique identifier that is a 16-byte RAW field.
The OID '' syntax is not documented in the Oracle documentation.
All this is doing is ensuring that during an EXP and subsequent IMP, the underlying type
PERSON_TYPE is in fact the same type. This will prevent an error that would occur if we performed
the following steps:
1. Create the PEOPLE table.
2. Export the table.
3. Drop the table and the underlying PERSON_TYPE.
4. Create a new PERSON_TYPE with different attributes.
5.