Oracle Built−in Packages- P155 ppsx

Deferred Transactions and Remote Procedure Calls Contents: About Deferred Transactions and RPCs DBMS_DEFER_SYS: Managing Deferred Transactions DBMS_DEFER: Building Deferred Calls DBMS_DE

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Parameters are summarized in the following table.

Name Description

sname Name of the schema that owns oname

oname Table whose conflict resolution statistics are to be deleted

start_date Beginning of date range for which statistics are to be deleted If NULL, all entries less than

end_date are deleted

end_date End of date range for which statistics are to be deleted If NULL, all entries greater than end_date

are deleted

There are no restrictions on calling PURGE_STATISTICS

16.6.1.3.1 Exceptions

The PURGE_STATISTICS procedure may raise the following exceptions:

Name Number Description

missingobject −23308 Object oname does not exist

missingschema −23306 Schema sname does not exist

16.6.1.3.2 Example

This example purges all records collected for the products table between 01−Jan−1998 and 01−Feb−1998:

BEGIN

DBMS_REPCAT.PURGE_STATISTICS(

sname => 'SPROCKET',

oname => 'PRODUCTS',

start_date => '01−JAN−1998',

end_date => '01−FEB−1998');

END;

16.5 Assigning Resolution

Methods with

DBMS_REPCAT

17 Deferred Transactions and Remote Procedure

Calls

[Appendix A] What's on the Companion Disk?

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Chapter 17

762

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17 Deferred Transactions and Remote Procedure Calls

Contents:

About Deferred Transactions and RPCs

DBMS_DEFER_SYS: Managing Deferred Transactions

DBMS_DEFER: Building Deferred Calls

DBMS_DEFER_QUERY: Performing Diagnostics and Maintenance

Oracle's advanced replication option relies primarily on deferred transactions and remote procedure calls (RPCs) When you commit a transaction against a replicated table, for example, the replication support

triggers queue a deferred transaction to do your bidding in one or more remote databases In addition to providing many of the underpinnings for the advanced replication option, the packages used to create and manipulate deferred calls are available for direct use in your applications You will use the packages described

in this chapter for deferred transactions and RPCs

DBMS_DEFER_SYS

Performs administrative tasks such as scheduling, executing, and deleting queued transactions

DBMS_DEFER

Builds deferred calls

DBMS_DEFER_QUERY

Provides access to parameters passed to deferred calls, primarily for diagnostic purposes

NOTE: Users must have explicit EXECUTE privileges on DBMS_DEFER in order to create

deferred calls

17.1 About Deferred Transactions and RPCs

This section provides some basic information you'll find useful in using the packages described in this

chapter

17.1.1 About Remote Destinations

Every remote procedure call has to be executed somewhere, and Oracle offers several methods of specifying

where

If you are using the advanced replication option, you have implicitly named the destinations for deferred RPCs and transactions by creating master sites Whenever a user performs DML on a table, the transaction is applied locally and is queued for delivery to all other sites where the table is replicated; these sites are listed in the DBA_REPSITES data dictionary view Similarly, replicated procedure calls are also queued for all master sites in the replicated environment Refer to Chapter 15, Advanced Replication, for details on using

DBMS_REPCAT, which performs most replicated environment administration operations

If you are not using the advanced replication option, then the destination site(s) are determined by one of the following means, listed in order of precedence:

1

The sites specified in the nodes parameter in the call to DBMS_DEFER.CALL, described later in this chapter

2

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The sites specified in the nodes parameter to DBMS_DEFER.TRANSACTION, described later in this chapter

3

The sites specified in the DEFDEFAULTDEST data dictionary view, described later in this chapter (Table 17.4)

If Oracle cannot determine a call's destination by any of these methods, or if you specify differing destinations

in the DBMS_DEFER.TRANSACTION and DBMS_DEFER.CALL procedures, the deferred call will raise

an exception

17.1.2 Data Dictionary Views

There are eight data dictionary views (see Table 17.1) that contain data about deferred transactions and RPCs You can query these views to determine information such as the destination of RPC calls, error messages, and scheduled execution times Most of the packages associated with deferred calls reference and/or modify the data in these views

Tables 17−2 through 17−9 provide details about the contents of these views

Table 17.1: Data Dictionary Views Associated with Deferred Calls

View Name Description

DEFCALL Contains information about all deferred RPCs Queries SYSTEM.DEF$_CALL

table

DEFCALLDEST Contains the destination database(s) for each deferred RPC in DEFCALL Queries

SYSTEM.DEF$_CALL, SYSTEM.DEF$_DESTINATION, SYSTEM.DEF$_CALLDEST, SYSTEM.DEF$_ERROR, and SYSTEM.REPCAT$_REPPROP

DEFDEFAULTDEST Contains the default destinations for deferred RPCs Queries

SYSTEM.DEF$_DEFAULTDEST

DEFERROR Contains error information for deferred calls that could not be applied at their

destination Queries SYSTEM

DEF$_ERROR

DEFERRORCOUNT Contains the count of errors for each destination Queries SYSTEM.DEF$_ERROR DEFSCHEDULE Contains information about the scheduling of deferred jobs Queries

SYSTEM.DEF$_DESTINATION and SYS.JOB$

DEFTRAN Contains information about all deferred calls Queries SYSTEM.DEF$_CALL and

SYS.USER$

DEFTRANDEST Contains the destination database(s) for each deferred transaction Queries

SYSTEM.DEF$_CALL, SYSTEM.DEF$_DESTINATION, SYSTEM.DEF$_ERROR, SYSTEM.DEF$_CALLDEST, and SYSTEM.REPCAT$_REPPROP

Table 17.2: Columns in DEFCALL Data Dictionary View

Column Name Description

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CALLNO Unique ID of call at deferred_tran_db

DEFERRED_TRAN_DB Global name of database that originated the call

DEFERRED_TRAN_ID Unique ID of the transaction

SCHEMANAME Schema that owns the package

PACKAGENAME Name of the package

PROCNAME Name of the procedure within the package

ARGCOUNT Number of arguments passed to the procedure

Table 17.3: Columns in DEFCALLDEST Data Dictionary View

DEFERRED_TRAN_ID Unique ID of the transaction Note that each deferred_tran_id has one or more

calls

DEFERRED_TRAN_DB Global name of database that originated the call

DBLINK Global name of the destination database

Table 17.4: Columns in DEFDEFAULTDEST Data Dictionary View

DBLINK Global name of the destination database

Table 17.5: Columns in DEFERROR Data Dictionary View

DEFERRED_TRAN_DB Global name of the database that originated the RPC

DEFERRED_TRAN_ID ID of the transaction originating or copying the deferred RPC

DESTINATION Database link used to specify the destination database

ERROR_TIME Time the error occurred

ERROR_NUMBER Oracle error number

ERROR_MSG Error message text

Table 17.6: Columns in DEFERRCOUNT Data Dictionary View

ERRCOUNT Number of errors in deferred RPC calls to destination

DESTINATION Global name of destination database

Table 17.7: Columns in DEFSCHEDULE Data Dictionary View

DBLINK Global name of the database for which pushes of deferred RPC calls is scheduled

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