Oracle Built−in Packages- P148 pdf

16.3.2.1.1 Exceptions The DEFINE_PRIORITY_GROUP procedure may raise the following exceptions: duplicateprioritygroup −23335 Priority group pgroup already exists missingschema −23306 Sche

Trang 1

comment Comment.

sname (Oracle7 only) Not used

16.3.2.1.1 Exceptions

The DEFINE_PRIORITY_GROUP procedure may raise the following exceptions:

duplicateprioritygroup −23335 Priority group pgroup already exists

missingschema −23306 Schema does not exist

nonmasterdef −23312 Calling site is not the master definition site

typefailure −23319 Datatype not supported

16.3.2.1.2 Restrictions

Note the following restrictions on calling DEFINE_PRIORITY_GROUP:

•

You must call the DEFINE_PRIORITY_GROUP procedure from the master definition site

•

You must call GENERATE_REPLICATION_SUPPORT for any object in the replication group for

the new priority group to become active

16.3.2.1.3 Example

Since priority groups are meant to work with a specific range of values, you must specify the datatype of these values when you create the group Valid datatypes follow:

CHAR

NCHAR (Oracle8 only)

VARCHAR2

NUMBER

DATE

RAW

If the data type is CHAR, then you must also specify the length of the data with the fixed_length parameter

After you create a priority group, you must run DBMS_REPCAT.GENERATE_REPLICATION_SUPPORT

for any object in the same replication group to propagate the new priority group to other master sites (Since

priority groups are not associated with a specific object, it does not matter what object you use in the call the

GENERATE_REPLICATION_SUPPORT.)

16.3.2.1.4 Creating a priority group for datatype CHAR

This call creates a priority group for a CHAR datatype For the sake of this example, assume that the range of

values is GREEN, YELLOW, RED, and the longest string is six characters long

BEGIN

DBMS_REPCAT.DEFINE_PRIORITY_GROUP(

gname => 'SPROCKET',

pgroup => 'PG_SIGNAL_COLORS',

datatype => 'CHAR',

fixed_length => 6,

comment => 'PG_SIGNAL_COLORS created '||sysdate); END;

Trang 2

16.3.2.1.5 Creating a priority group for datatype VARCHAR

For all other datatypes, the use of the fixed_length parameter does not apply This statement creates a priority group for use with the PRODUCTION_STATUS field in the PRODUCTS table:

BEGIN

DBMS_REPCAT.DEFINE_PRIORITY_GROUP(

pgroup => 'PG_PRODUCTION_STATUS',

datatype => 'VARCHAR',

comment => 'PG_PRODUCTION_STATUS created '||sysdate); END;

16.3.2.2 The DBMS_REPCAT.DROP_PRIORITY_GROUP procedure

The DROP_PRIORITY_GROUP procedure lets you drop a priority group that you have defined The

specifications differ for Oracle7 and Oracle8 as follows

here is the Oracle7 specification:

PROCEDURE DBMS_REPCAT.DROP_PRIORITY_GROUP

(gname IN VARCHAR2 := '',

pgroup IN VARCHAR2,

sname IN VARCHAR2 := '');

Here is the Oracle8 specification:

PROCEDURE DBMS_REPCAT.DROP_PRIORITY_GROUP

pgroup IN VARCHAR2);

Parameters are summarized in the following table

gname Name of the replication group containing the priority group

pgroup Name of the priority group to drop

WARNING: Do not drop a priority group that you have designated as an UPDATE conflict

resolution method for a column group You must first use DROP_UPDATE_RESOLUTION

for the column group Records in the data dictionary view DBA_REPRESOLUTION indicate

if and where the priority group is used Attempting to drop a priority group that is in use

raises the referenced exception.

The DROP_PRIORITY_GROUP procedure may raise the following exceptions:

missingrepgroup −23373 Replication group gname does not exist

referenced −23332 Priority group pgroup is used by existing conflict resolution methods

16.3.2 Creating, Maintaining, and Dropping Priority Groups 727

Trang 3

You must call DBMS_REPCAT.DROP_PRIORITY_GROUP from the master definition site

16.3.2.2.3 Example

You can use DBMS_REPCAT.DROP_PRIORITY_GROUP as follows to remove a particular priority group from the replication group:

BEGIN

DBMS_REPCAT.DROP_PRIORITY_GROUP(

gname =>'SPROCKET',

pgroup =>'PG_PRODUCTION_STATUS');

END;

16.3.2.3 The DBMS_REPCAT.COMMENT_ON_PRIORITY_GROUP procedure

The COMMENT_ON_PRIORITY_GROUP procedure allows you to create or replace the comment for a priority group (as seen in the DBA_REPPRIORITY_GROUP data dictionary view) The specifications for Oracle7 and Oracle8 differ as follows

PROCEDURE DBMS_REPCAT.COMMENT_ON_PRIORITY_GROUP

pgroup IN VARCHAR2,

comment IN VARCHAR2,

PROCEDURE DBMS_REPCAT.COMMENT_ON_PRIORITY_GROUP

pgroup IN VARCHAR2,

comment IN VARCHAR2);

gname Name of the replication group containing the priority group

pgroup Name of the priority group

The COMMENT_ON_PRIORITY_GROUP procedure may raise the following exceptions:

missingprioritygroup −23336 Priority group pgroup does not exist

Trang 4

You must call COMMENT_ON_PRIORITY_GROUP from the master definition site

16.3.2.3.3 Example

The following illustrates how you can replace the comment for the PG_SIGNAL_COLORS priority group:

BEGIN

DBMS_REPCAT.COMMENT_ON_PRIORITY_GROUP(

comment => 'Valid values are GREEN, YELLOW, and RED');

END;

16.3.3 Creating and Maintaining Priorities Within a Priority Group

The next step after creating a priority group is to add priorities to it This task entails specifying every possible value for the data in the priority group, and assigning a priority to each value

For example, recall the PRODUCTION_STATUS field we described earlier, which has this range of five possible values:

1

CONCEPT

2

DEVELOPMENT

3

BETA

4

PRODUCTION

5

DISCONTINUED

We want to resolve conflicts for this data by accepting the data that is furthest in the production cycle If a conflict arises in which one update has PRODUCTION_STATUS set to "BETA," and another update has it set to "PRODUCTION," we would take the data from the latter update

The examples in the following sections illustrate exactly how to implement this priority group We will show the following packages:

DBMS_REPCAT.ADD_PRIORITY_<datatype>

DBMS_REPCAT.ALTER_PRIORITY

DBMS_REPCAT.ALTER_PRIORITY_<datatype>

DBMS_REPCAT.DROP_PRIORITY

DBMS_REPCAT.DROP_PRIORITY_<datatype>

NOTE: Each of the procedures containing the <datatype> suffix actually has five different

versions in Oracle7, one for each of the datatypes CHAR, VARCHAR2, NUMBER, RAW,

and DATE Oracle8 adds support for two more datatypes: NCHAR and NVARCHAR2 The

usage of each of these packages is identical Most of the examples in the following sections

will use the VARCHAR2 version of these packages

16.3.2 Creating, Maintaining, and Dropping Priority Groups 729

Trang 5

16.3.3.1 The DBMS_REPCAT.ADD_PRIORITY_<datatype> procedure

The ADD_PRIORITY_<datatype> procedure adds a member (of the specified datatype) to an existing priority group The specifications differ for Oracle7 and Oracle8 as follows

PROCEDURE DBMS_REPCAT.ADD_PRIORITY_<datatype>

pgroup IN VARCHAR2,

value IN {CHAR|VARCHAR2|NUMBER|DATE|RAW,

priority IN NUMBER,

PROCEDURE DBMS_REPCAT.ADD_PRIORITY_<datatype>

pgroup IN VARCHAR2,

value IN {CHAR|NCHAR|VARCHAR2|NUMBER|DATE|RAW,

priority IN NUMBER)

In these specifications, <datatype> can be any of the following, and value can be any of these types:

CHAR

VARCHAR2

NUMBER

DATE

RAW

NCHAR (Oracle8 only)

NVARCHAR2 (Oracle8 only)

gname Name of the replication group to which priority group pgroup belongs

pgroup Priority group to which new value and priority are being added

value Literal value that is being assigned added to pgroup

priority Priority designated to value

This procedure may raise the following exceptions:

duplicatepriority −23335 Another value is already designated with priority priority

duplicatevalue −23338 Value is already in the priority group pgroup

missingprioritygroup −23336 Priority group pgroup does not exist

typefailure −23319 Datatype of value is not the same as the datatype for priority group pgroup

Định dạng
Số trang	5
Dung lượng	80,01 KB