Oracle Built−in Packages- P129 pdf

14.4.2.1.1 ExceptionsThe CREATE_SNAPSHOT_REPGROUP procedure raises the following exceptions: Name Number Description commfailure −23317 Unable to communicate with master dbnotcompatible

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14.4.2.1.1 Exceptions

The CREATE_SNAPSHOT_REPGROUP procedure raises the following exceptions:

Name Number Description

commfailure −23317 Unable to communicate with master

dbnotcompatible −23375 Attempt to use SYNCHRONOUS propagation in pre−7.3 database

duplicaterepgroup −23374 Replication group gname already exists

nonmaster −23312 The master parameter is not a master site

norepoption −23364 Replication option not installed

typefailure −23319 propagation_mode not specified correctly

14.4.2.1.2 Restrictions

Note the following restrictions on calling CREATE_SNAPSHOT_REPGROUP:

•

You must be connected to the replication administrator account (typically REPADMIN) to call the CREATE_SNAPSHOT_REPGROUP procedure

•

The snapshot group name must match the name of the master replication group

14.4.2.2 The offline snapshot instantiation procedure

The procedure for performing offline instantiation of snapshots in an advanced replication environment (using the CREATE SNAPSHOT command and the DBMS_OFFLINE_SNAPSHOT and DBMS_REPCAT

packages) follows:

1

Create a snapshot log for each master table if one does not already exist

2

Create a snapshot of each master table in the master database, and in the same schema as the master

table Of course, the name of the snapshot will have to be different from the name of the master table.

The CREATE SNAPSHOT statement must also include a loopback database link qualifier

CREATE SNAPSHOT snp_countries

AS SELECT * FROM countries@D7CA.BIGWHEEL.COM@TCPIP

3

Perform user exports of all schema that own master tables You should be logged on to the schema owner account for these exports The only tables that you need to export are the snapshot base

tables −− that is, those whose names begin with "SNAP$_"

4

Copy the export dump file(s) to the new snapshot site(s)

5

Use CREATE_SNAPSHOT_REPGROUP at the snapshot sites to create a new snapshot replication object group The name of this object group should be the same as the name of the replication group

of which the master tables are members

14.4.2 Creating and Dropping Snapshot Replication Groups 631

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BEGIN DBMS_REPCAT.CREATE_SNAPSHOT_REPGROUP(

gname => 'SPROCKET', master => 'D7CA.BIGWHEEL.COM', comment => 'Group created on '||sysdate|| ' by '||user, propagation_mode=> 'ASYNCHRONOUS');

END;

6

Call DBMS_OFFLINE_SNAPSHOT.BEGIN_LOAD to begin loading the data from the export

file(s) You must call the procedure for every snapshot you plan to import

BEGIN DBMS_OFFLINE_SNAPSHOT.BEGIN_LOAD(

gname => 'SPROCKET', sname => 'SPROCKET', master_site => 'D7CA.BIGWHEEL.COM' snapshot_oname => 'SNP_COUNTRIES' storage_c => 'TABLESPACE sprocket_data STORAGE (INITIAL 64K)' comment => 'Load of COUNTRIES snapshot begun at '||sysdate); END;

7

Import the snapshot base table(s) from the export file(s) created in step 4

8

Call DBMS_OFFLINE_SNAPSHOT.END_LOAD for each snapshot when the load is complete

BEGIN DBMS_OFFLINE_SNAPSHOT.END_LOAD(

gname => 'SPROCKET' sname => 'SPROCKET' snapshot_oname => 'SNP_COUNTRIES');

END;

14.4.2.3 The DBMS_REPCAT.DROP_SNAPSHOT_REPGROUP procedure

The DBMS_REPCAT package's DROP_SNAPSHOT_REPGROUP procedure is the counterpart to the

CREATE_SNAPSHOT_REPGROUP procedure As you would suspect, this procedure drops an existing

snapshot replication group, and optionally, all member snapshots Here's the specification:

PROCEDURE DBMS_REPCAT>DROP_SNAPSHOT_REPGROUP

(gname IN VARCHAR2,

drop_contents IN BOOLEAN := FALSE);

Parameters are summarized in the following table

Name Description

gname Name of the snapshot group

drop_contents If TRUE, objects in gname are dropped If FALSE (the default) they are simply no longer

replicated

The DROP_SNAPSHOT_REPGROUP procedure raises the following exceptions:

missingrepgroup −23373 Replication group gname does not exist

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nonmaster −23313 Calling site is not a snapshot site

If drop_contents is set to FALSE, the triggers created to support snapshot modifications remain

14.4.2.3.3 Example

The following example illustrates the dropping of a snapshot replication group with the

DROP_SNAPSHOT_REPGROUP procedure:

BEGIN

DBMS_REPCAT.DROP_SNAPSHOT_REPGROUP(

gname => 'SPROCKET',

drop_objects => TRUE);

END;

Here, we drop the snapshot replication group SPROCKET and drop the member snapshots as well

14.4.3 Adding and Removing Snapshot Replication Group Objects

The CREATE_SNAPSHOT_REPOBJECT and DROP_SNAPSHOT_REPOBJECT procedures add and remove objects, respectively, from a snapshot replication group These objects may be snapshots, packages, package bodies, procedures, synonyms, or views

14.4.3.1 The DBMS_REPCAT.CREATE_SNAPSHOT_REPOBJECT procedure

The CREATE_SNAPSHOT_REPOBJECT procedure adds an object to a snapshot replication group For new snapshot objects, this procedure generates row−level replication triggers for snapshots if the master table uses row−level replication The specifications differ for Oracle7 and Oracle8 as follows

Here is the Oracle7 specification:

PROCEDURE DBMS_REPCAT CREATE_SNAPSHOT_REPOBJECT

(sname IN VARCHAR2,

oname IN VARCHAR2,

type IN VARCHAR2,

ddl_text IN VARCHAR2 := '',

comment IN VARCHAR2 := '',

gname IN VARCHAR2 := '',

gen_objs_owner IN VARCHAR2 := '');

Here is the Oracle8 specification:

PROCEDURE DBMS_REPCAT.CREATE_SNAPSHOT_REPOBJECT

(sname IN VARCHAR2,

oname IN VARCHAR2,

type IN VARCHAR2,

ddl_text IN VARCHAR2 := '',

comment IN VARCHAR2 := '',

gname IN VARCHAR2 := '',

gen_objs_owner IN VARCHAR2 := '',

min_communication IN BOOLEAN := TRUE);

NOTE: The only difference between the Orace7 and Oracle8 implementations is the addition

of the min_communication parameter in Oracle8

Parameters are summarized in the following table

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Name Description

sname Name of schema to which oname belongs

oname Name of object to be added

type Object type Supported types are PACKAGE, PACKAGE BODY, PROCEDURE,

SNAPSHOT, SYNONYM, and VIEW

ddl_text DDL used to create object (for type SNAPSHOT only)

comment Comment on object, visible in DBA_REPOBJECT data dictionary view

gname Name of snapshot group to which object is being added Defaults to sname if not

specified

gen_objs_owner Name of the schema in which to create the generated trigger and trigger package or

procedure wrapper for the object Defaults to sname

drop_objects If set to TRUE, object is dropped too If FALSE (the default), object is only removed

from the snapshot group

min_communication

(Oracle8 only)

Must be FALSE if any master site is running Oracle7 TRUE, the default setting, uses the minimum communication algorithm

14.4.3.1.1 Exceptions.

CREATE_SNAPSHOT_REPGROUP raises the following exceptions:

commfailure −23317 Unable to communicate with master site

ddlfailure −23318 Unable to perform DDL

duplicateobject −23309 Object oname already exists

missingobject −23308 Object oname does not exist in master's replication group gname

missingremoteobject −23381 Master site has not generated replication support for oname

missingschema −23306 Schema sname does not exist

misssnapobject −23355 Object oname does not exist at master

nonmaster −23312 Master site associated with snapshot group is no longer a master site

nonsnapshot −23314 Calling site is not a snapshot site

typefailure −23319 Invalid value for type

NOTE: CREATE_SNAPSHOT_REPOBJECT is called from the replication administrator

(typically REPADMIN) account If you are creating an snapshot with ddl_text, be sure to

specify the schema in which it should be created (if other than the replication administrator

account)

14.4.3.1.2 Example

The following example illustrates how to add an object to an existing snapshot replication group:

BEGIN

DBMS_REPCAT.CREATE_SNAPSHOT_REPOBJECT(

sname => 'SPROCKET',

oname => 'PRICE_LIST',

type => 'SNAPSHOT' ,

ddl_text=>

'CREATE SNAPSHOT SPROCKET.PRICES AS SELECT * FROM

14.4.3 Adding and Removing Snapshot Replication Group Objects 634

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PRICES@D7CA.BIGWHEEL.COM' ,

gnam => 'SPROCKET',

gen_objs_owner => 'SPROCKET')

END;

BEGIN

14.4.3.2 The DBMS_REPCAT.DROP_SNAPSHOT_REPOBJECT procedure

The DROP_SNAPSHOT_REPOBJECT procedure drops an object from a snapshot replication group

PROCEDURE DBMS_REPCAT.DROP_SNAPSHOT_REPOBJECT

(sname IN VARCHAR2,

oname IN VARCHAR2,

type IN VARCHAR2,

drop_objects IN BOOLEAN := FALSE);.

For parameter descriptions, see the table in the Section 14.4.3.1, "The

DBMS_REPCAT.CREATE_SNAPSHOT_REPOBJECT procedure"" section

DROP_SNAPSHOT_REPOBJECT raises the following exceptions:

missingobject −23308 Object oname does not exist in master's replication group gname

nonsnapshot −23314 Calling site is not a snapshot site

typefailure −23319 Invalid value for type

If the type parameter in DROP_REPOBJECT is SNAPSHOT and you do not set the drop_objects parameter

to TRUE, replication triggers and associated packages remain in the schema, and deferred transactions (if any) remain in the DEFTRANS queue

14.4.3.2.3 Example

The following example drops an object from a snapshot replication group:

DBMS_REPCAT.FTOP_SNAPSHOT_REPOBJECT(

sname => 'SPROCKET',

oname => 'PRICE_LIST',

type => 'SNAPSHOT',

drop_objects=> TRUE);

END;

14.4.4 Altering a Snapshot Replication Group's Propagation Mode

The ALTER_SNAPSHOT_PROPAGATION procedure changes a snapshot replication group's propagation mode The propagation mode can be either SYNCHRONOUS or ASYNCHRONOUS When you call this procedure, Oracle does the following:

•

Pushes any transactions that exist in the deferred RPC queue for the group

•

14.4.3 Adding and Removing Snapshot Replication Group Objects 635

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