This chapter describes restrictions for XStream In.
This chapter contains these topics:
This section describes restrictions for inbound servers.
This section contains these topics:
An inbound server does not apply row LCRs containing the results of DML changes in columns of the following data types:
BFILE
ROWID
The following user-defined types: varrays, REFs, and nested tables
The following Oracle-supplied types: ANYTYPE, ANYDATASET, URI types, SDO_TOPO_GEOMETRY, SDO_GEORASTER, and Expression.
An inbound server raises an error if it attempts to apply a row LCR that contains information about a column of an unsupported data type. In addition, an inbound server cannot apply DML changes to the following types of tables:
Temporary tables
Object tables that include unsupported data types
An inbound server raises an error if it attempts to apply such changes. When an inbound server raises an error for an LCR, it moves the transaction that includes the LCR into the error queue.
These data type restrictions pertain to both ordinary (heap-organized) tables and index-organized tables.
See Also:
Oracle Database SQL Language Reference for information about data types
Statement DML handlers cannot process LONG, LONG RAW, or nonassembled LOB column data in row LCRs. However, statement DML handlers can process LOB column data in row LCRs that have been constructed by LOB assembly. LOB assembly is enabled by default for statement DML handlers.
Procedure DML handlers and error handlers cannot process LONG or LONG RAW column data in row LCRs. However, procedure DML handlers and error handlers can process both nonassembled and assembled LOB column data in row LCRs, but these handlers cannot modify nonassembled LOB column data.
See Also:
Oracle Streams Replication Administrator's Guide for information about LOB assembly
Oracle Database SQL Language Reference for more information about data types
The following types of DDL changes are not supported by an inbound server. These types of DDL changes are not applied:
ALTER MATERIALIZED VIEW
ALTER MATERIALIZED VIEW LOG
CREATE DATABASE LINK
CREATE SCHEMA AUTHORIZATION
CREATE MATERIALIZED VIEW
CREATE MATERIALIZED VIEW LOG
DROP DATABASE LINK
DROP MATERIALIZED VIEW
DROP MATERIALIZED VIEW LOG
FLASHBACK DATABASE
RENAME
If an inbound server receives a DDL LCR that specifies an operation that cannot be applied, then the inbound server ignores the DDL LCR and records the following message in the inbound server trace file, followed by the DDL text that was ignored:
Inbound server ignored the following DDL:
An inbound server applies all other types of DDL changes if the DDL LCRs containing the changes should be applied according to the inbound server rule sets.
Note:
An inbound server applies ALTER object_type object_name RENAME changes, such as ALTER TABLE jobs RENAME. Therefore, if you want DDL changes that rename objects to be applied, then use ALTER object_type object_name RENAME statements instead of RENAME statements. After changing the name of a database object, new rules that specify the new database object name might be needed to replicate changes to the database object.
The name "materialized view" is synonymous with the name "snapshot". Snapshot equivalents of the statements on materialized views are ignored by an inbound server.
See Also:
"Rules and Rule Sets"For a DDL LCR to be applied at a destination database successfully, the user specified as the current_schema in the DDL LCR must exist at the destination database. The current schema is the schema that is used if no schema is specified for an object in the DDL text.
See Also:
Oracle Database Concepts for more information about database structures
Oracle Database PL/SQL Packages and Types Reference for more information about the current_schema attribute in DDL LCRs
This section describes XStream In restrictions for rules.
This section contains these topics:
The following restrictions apply to subset rules:
A table with the table name referenced in the subset rule must exist in the same database as the subset rule, and this table must be in the same schema referenced for the table in the subset rule.
If the subset rule is in the positive rule set for an inbound server, then the table must contain the columns specified in the subset condition, and the data type of each column must match the data type of the corresponding column in row LCRs that evaluate to TRUE for the subset rule.
Creating subset rules for tables that have one or more columns of the following data types is not supported: LOB, LONG, LONG RAW, user-defined types (including object types, REFs, varrays, nested tables), and Oracle-supplied types (including Any types, XML types, spatial types, and media types).
See Also:
Oracle Database SQL Language Reference for more information about data types
This section describes restrictions for rule-based transformations.
See Also:
"Rule-Based Transformations"Except for add column transformations, declarative rule-based transformations that operate on columns support the same data types that are supported by inbound servers.
Add column transformations cannot add columns of the following data types: BLOB, CLOB, NCLOB, BFILE, LONG, LONG RAW, ROWID, user-defined types (including object types, REFs, varrays, nested tables), and Oracle-supplied types (including Any types, XML types, spatial types, and media types).
See Also:
Oracle Database SQL Language Reference for information about data types
The maximum size of the VARCHAR2, NVARCHAR2, and RAW data types has been increased in Oracle Database 12c when the COMPATIBLE initialization parameter is set to 12.0.0 and the MAX_STRING_SIZE initialization parameter is set to EXTENDED. XStream In supports these extended data types.
However, the following limitations apply to the extended data types:
Information about an extended data type column might not be contained in the original LCR for a data manipulation language (DML) operation. Instead, XStream In might treat the extended data type column similar to the way it treats LOB columns. Specifically, additional LCRs might contain the information for the extended data type column.
XStream rules cannot access data in LCRs for extended data type columns.
Extended data type columns cannot be specified in a subset rule clause.
Extended data type columns cannot be used for conflict detection.
Extended data type columns cannot be used for a substitute primary key for apply purposes with the DBMS_APPLY_ADM.SET_KEY_COLUMNS procedure.
Extended data type columns cannot be used in the following types of declarative rule-based transformations:
Add column
Keep columns
See Also:
Oracle Database SQL Language Reference for more information about extended data types