Creates and initializes a subscription and materializes subscription data. The subscription may be for a database replication definition, table replication definition, function replication definition, or publication. You can create a database subscription with materialization of the whole database or a subset of the tables. The command supports "and", "or", and "in value list" operators in subscription where clauses. The limitation for this support is that each sub-clause in "and" and "or" must conform and adhere to current SAP Replication Server standards.
To create a database subscription:
create subscription <subname> for database replication definition <repdefname> with primary at <pdsname.pdbname> with replicate at <rdsname.rdbname> {with materialization [init replicate table with {create | create_or_truncate | truncate | recreate} [date time] [user <username> password <password>]] | without materialization} [subscribe to truncate table]
To create a non-database subscription:
create subscription <subname> for {table_repdef | func_repdef | publication pub} [with primary at <pdsname.pdbname>] with replicate at <rdsname.rdbname> [where {{column_name | @param_name} {< | > | >= | <= | = | &} value [and {column_name | @param_name} {< | > | >= | <= | = | &} value]... [or where { column_name | @param_name } {< | > | >= | <= | = | &} value [and {column_name |@param_name} {< | > | >= | <= | = | &} value]...]} | {{column_name | @param_name} in (value1,value2,value3...) [and {column_name | @param_name} in (value1,value2,value3...)]... [or where { column_name | @param_name } in (value1,value2, value3...) [and {column_name |@param_name} in(value1,value2,value3...)...]...]}] [without holdlock [direct_load [init replicate table with {create | create_or_truncate | truncate | recreate}] [user username password pass][num_of_selects selects] [hold_resource_on_error]]| incrementally | without materialization] [subscribe to truncate table] [for new articles]
The name of the subscription, which must conform to the rules for naming identifiers. The subscription name must be unique for the replication definition, where applicable, and for the replicate data server and database.
Specifies the table replication definition the subscription is for.
Specifies the name of the function replication definition the subscription is for.
Specifies the publication the subscription is for.
Specifies the database replication definition the subscription is for.
Specifies the location of the primary data. If the primary database is part of a warm standby application that uses logical connections, <data_server.database> is the name of the logical data server and database. You can also specify an alternate primary connection name in the clause if you are configuring a multi-path replication system.
Specifies the location of the replicate data. If the replicate database is part of a warm standby application, <data_server.database> is the name of the logical data server and database. You can also specify an alternate replicate connection name in the clause if you are configuring a multi-path replication system. For table subscriptions created with the direct_load option, this is the name of the physical data server and database name; logical or alternate connection names are not allowed.
Sets criteria for the column or parameter values that are to be replicated via the subscription. If you omit the where clause, all rows or parameters are replicated.
You can include a where clause in a subscription for a table or function replication definition. You cannot include a where clause in a database or publication subscription.
A where clause is composed of one or more simple comparisons, in which a searchable column or searchable parameter from the replication definition is compared to a literal value using one of these relational operators: <, >, <=, >=, =, or &. (The & operator is supported only for <rs_address> columns or parameters.) You can join comparisons using the keyword and and or. You can group all the rules of one column to a in value list. Example 13 illustrates this scenario.
Column or parameter names used in the expression must be included in the searchable columns list of the table replication definition or the searchable parameters list of the function replication definition.
Java columns cannot be evaluated in subscription expressions. Thus, you cannot include a Java column of type <rawobject> or <rawobject in row> in a where clause.
The maximum size of a where clause in a subscription is 255 characters.
You cannot convert binaries with less than seven bytes into integers. Workarounds include using zeros to pad binary values up to eight bytes, or using integer values instead of binary values.
A column name from the primary table, for a subscription to a table replication definition.
A parameter name from a replicated stored procedure, for a subscription to a function replication definition.
A value for a specified column or parameter. See Datatypes for entry formats for values for different datatypes.
Column or parameter names used in the expression must be included in the searchable columns or searchable parameters list of the replication definition.
Selects data from the primary database without a holdlock, for non-atomic materialization. The rows are applied at the replicate database in increments of 1000-row inserts per transaction. For subscriptions created with the direct_load option, the number of rows applied is determined by the mat_load_tran_size configuration parameter. See “Nonatomic Materialization” for more information.
Creates the table at the replicate database. If the table already exists, the materialization fails.
Creates the table at the replicate database. If the table already exists, Replication Server uses the existing table after truncation.
Truncates the table at the replicate database. If the table does not exist, materialization fails.
Initializes the subscription and apply subscription data in increments of 1000-row inserts per transaction. A holdlock is used on the primary database, for atomic materialization.
Does not materialize data for the subscription. Use this option when there is no activity at the primary database and the data already exists in the replicate database. Or, use this option when you have suspended activity in the primary database and manually transferred the data to the replicate database. Database subscriptions must include this option.
For a subscription to a table replication definition, a database replication definition, or to a publication, enables replication of the truncate table command to the subscribing replicate database.
You must set this option the same as it is set for any existing subscriptions that replicate data into the same replicate table for a particular database. Otherwise, the new subscription is rejected.
Refreshes an existing subscription. Instructs Replication Server to check the subscription against the publication and then to create subscriptions against unsubscribed articles.
Enables direct load materialization.
When this option is used, no other subscription can be created at the same time for the same replicate table. You can only use this option against a physical database connection, not an alternate or logical connection.
This option is available only if the replicate SAP Replication Server site version and route version to its primary SAP Replication Server are 1571100 or later.
The user ID and password used in direct load materialization to connect to the primary Adaptive Server database or Replication Agent and select from the primary table.
Enables multiple select threads to improve the materialization performance for subscriptions created with direct_load option. The default value is 1, and valid values are 1 – 10. You can use this option only with the direct_load option, and it is available only when the primary database is either DB2 UDB 9.7 and later, or Oracle, and when the function string rs_select is not customized. This number is adjusted down to 1 otherwise, or when there are not many rows in the primary table.
Holds the resource for the subscription if the subscription created with direct load materialization results in an error.The default is not hold resource when a subscription created with the direct_load option results in an error.
Creates a subscription named <titles_sub>. It specifies that rows from the <titles >table with columns of the type “business” are to be replicated in the <titles> table in the <pubs2> database of the data server named SYDNEY_DS:
create subscription titles_sub for titles_rep with replicate at SYDNEY_DS.pubs2 where type = 'business’
Creates a subscription named <titles_sub> that includes rows from the <titles> table with prices that are greater than or equal to $10.00:
create subscription titles_sub for titles_rep with replicate at SYDNEY_DS.pubs2 where price >= $10.00
Creates a subscription named <myproc_sub> for the function replication definition <myproc_rep>. In order to use this command to create a subscription for a function replication definition, data must already exist at the replicate database, and you must use the without materialization clause:
create subscription myproc_sub for myproc_rep with replicate at SYDNEY_DS.pubs2 without materialization
Creates a subscription named <pubs2_sub> for the publication <pubs2_pub>:
create subscription pubs2_sub for publication pubs2_pub with primary at TOKYO_DS.pubs2 with replicate at SYDNEY_DS.pubs2
create subscription pubs2_sub for database replication definition pubs2_rep with primary at NEWYORK_DS.pubs2 with replicate at TOKYO_DS.pubs2 without materialization subscribe to truncate table
create subscription sub_conn2 for repdef_conn2 with replicate at NY_DS.rdb_conn2 without materialization go
create subscription sub_conn2 for repdef_conn2 with primary at LON_DS.pdb_conn2 with replicate at NY_DS.rdb without materialization go
Creates a subscription with the direct load option named <titles_sub> that includes rows from the <titles> table with prices that are greater than or equal to $10.00:
create subscription titles_sub for titles_rep with replicate at SYDNEY_DS.pubs2 where price >= $10.00 without holdlock direct_load
Creates a subscription with the direct load option named <titles_sub> that includes rows from the <titles> table with sales greater than 5,000 copies:
create subscription titles_sub for titles_rep with replicate at SYDNEY_DS.pubs2 where total_sales > 5000 without holdlock direct_load user pubs2_owner password pubs2_owner_pwd
Creates a subscription with the direct_load option named authors_sub with at most 3 select threads:
create subscription authors_sub for authors_repdef with replicate at ost_replnxb10_01.rdb1 without holdlock direct_load 3 selects
create subscription sub_name for {table_repdef | func_repdef | {publication pub | database replication definition db_repdef} with primary at server_name.db} with replicate at data_server.database [where {column_name | @param_name} in {value1,value2,value3...} [and {column_name | @param_name} in {value1,value2,value3...}]... [or where { column_name | @param_name } in {value1,value2, value3...} [and {column_name |@param_name} in{value1,value2,value3...]...]...]
create subscription tb_name_demo for tb_name_repdefdemo with replicate at rqa10.tdb2 where col1 > 20 and col1 < 100 or where col2 = 'charvalue0' or where col3 = 'varcharvalue0'
create subscription tb_name_subdemo for tb_name_repdefdemo with replicate at rqa10.tdb2 where col2 in ('charvalue0','charvalue2', 'charvalue3','charvalue4') or where col3 in ('varcharvalue0')
To subscribe to a function or database replication definition, use create subscription with the without materialization clause, or use define subscription and the other bulk materialization commands.
Execute create subscription at the Replication Server of the database where the replicated data will be stored.
See the Replication Server Administration Guide Volume 1 for more information about subscriptions and the role they play in replication.
Starting from Replication Server 15.5, if you change a replication definition that has table subscriptions, you do not have to drop and re-create the table subscriptions.
You can create multiple replication definitions for the same primary table or database. You cannot subscribe to more than one replication definition for the same replicate table or database, although you can subscribe to the same replication definition more than once.
Support for subscription materialization of LOB compressed data depends on how you specify the column datatype in the replication definition and on the version of Replication Server. See Subscription Materialization of LOB Compressed Data in the Replication Server Administration Guide Volume 1.
If you are using quoted identifiers with a custom function string that includes a quoted constant, create subscription without a quoted constant or without materialization clause. Otherwise, during subscription materialization the quoted constant causes a query failure. The replicate data server identifies the quoted constant as a column instead of a constant.
Subscribing to Database Replication Definitions
When you create a database subscription, you cannot use the where clause to limit data subscription. All data is subscribed.
With database subscriptions, you can use only the no materialization or bulk materialization methods. Use define subscription to use dump and load or other bulk materialization method. Use create subscription to use the no materialization method.
You cannot subscribe to more than one database replication definition from the same origin.
If your replicate Replication Server is at lower version than your primary Replication Server, you cannot create a database subscription at the replicate Replication Server for a primary database controlled by the primary Replication Server.
To successfully create a table replication definition for a primary database that is subscribed by a database subscription, the replicate Replication Server must be at the same or higher version as the table replication definition.
Subscribing to Publications
When a publication is valid, you can create a subscription for the publication in order to begin replication to a replicate database. All forms of subscription materialization are supported.
When you use atomic or non-atomic materialization, article subscriptions are materialized one at a time in the order that the articles were added to the publication.
When you use create subscription with the without materialization clause, all article subscriptions are activated and validated at the same time.
A subscription to a publication cannot include a where clause. Instead, you can customize replication to replicate sites by including one or more where clauses in each article the publication contains.
Specifying Columns Subject to HDS Translations
When you create a subscription that includes a where clause, make sure that the value in the where clause comparison is in the declared datatype format.
Subscriptions that specify columns subject to class- or column-level translations in the where clause cannot be dematerialized automatically. You must use either the bulk or the no-materialization method.
Replicating Truncate Table
Requirements for Executing create subscription
In addition to the permissions listed below, make sure that these requirements are met before you execute create subscription.
A replication definition exists for the primary table you are replicating, and the table is marked for replication with sp_setreptable.
If you subscribe to tables marked using sp_reptostandby, you must configure the primary database connection using the rep_as_standby configuration parameter and configure Replication Agent using send_warm_standby_exacts.
Tables referenced in the replication definition exist in both the primary and the replicate database. Each table has the columns and datatypes defined in the replication definition.
This table is visible to the user creating the subscription and to the user maintaining it. The easiest way to achieve this is to have the Database Owner creates the table.
A replication definition exists for the stored procedure you are replicating, and the stored procedure is marked for replication with sp_setrepproc.
Stored procedures referenced in the function replication definition exist in both the primary and replicate database. Each stored procedure has the parameters and datatypes defined in the function replication definition.
For a subscription to a publication:
A publication exists that contains articles for the primary tables or stored procedure you are replicating. The articles specify replication definitions that meet the requirements described above.
The publication is valid.
Requirements for Warm Standby Applications
If the destination database is part of a warm standby application, the table must exist in both the active and standby databases. Both tables must be marked for replication using sp_setreptable or sp_reptostandby.
For a logical primary database, you cannot create a subscription while Replication Server is in the process of adding a standby database.
You cannot create table subscriptions against warm standby connections with the direct_load option.
Requirements for Tables with the Same Name
If there is a replication definition for a primary table named <db.dbo.table1>, and
Database user “jane” owns a table named <db.jane.table1>, then
Jane cannot create a subscription to the replication definition for <db.dbo.table1> using the default function strings.
Atomic Materialization
The default method for materializing subscriptions with this command is atomic materialization. Atomic materialization locks the primary table and copies subscription data through the network in a single atomic operation.
During atomic materialization, no rows appear at the replicate database until the select transaction has been completed in the primary database. If the subscription specifies a large number of rows, the select transaction can run for a long time, causing a delay at the replicate site.
Requirements for Using Atomic Materialization
You or the Database Owner must own the primary table, or you must use user-defined function strings for select operations at the primary database.
The Database Owner or the maintenance user must own the replicate table, or you must use user-defined function strings for select operations at the replicate database. If the owner of the replicate table is different from the owner of the primary table, you must create a unique function string by using a distinct function-string class.The primary database must be an Adaptive Server database.
Using the Without Holdlock or Incrementally Option
The without holdlock or incrementally options are alternatives to the default atomic method of subscription materialization. When you specify these options, Replication Server applies the rows in batches, so that data appears at the replicate database a batch at a time.
As a result, during materialization, queries at the replicate database may return incomplete data for the subscription. This temporary condition ends when check subscription indicates the subscription is valid.
The Incrementally Option
The incrementally option is a variation of atomic materialization. Use this option for large subscriptions to avoid a long-running transaction at the replicate database. The subscription data is not applied atomically at the replicate database, so the data is available; however, it is incomplete until materialization has completed and the subscription is validated.
When incrementally is used, select is performed with a holdlock to maintain serial consistency with the primary database. The replicate table passes through states that occurred previously at the primary database.
In all cases, replicate data is consistent with the primary database by the time materialization completes and check subscription indicates that the subscription is valid.
Nonatomic Materialization
The without holdlock option uses non-atomic materialization. When this option is specified, materialization rows are selected from the primary database without a holdlock. This can introduce inconsistency if rows are updated at the primary database after the select. To correct inconsistencies, use set autocorrection on when using without holdlock.
When data already exists at the replicate database, you can use atomic or non-atomic materialization instead of bulk materialization.
Requirements for Using Nonatomic Materialization
Do not use without holdlock if you update data by distributing applied functions from the primary database or if you update the data with commutative functions. For example, if a stored procedure updates a row by incrementing the previous value of a column, the value may be incorrect when materialization has completed.
For non-atomic subscriptions, if a non-atomic subscription is materializing when switch active executes, it is marked “SUSPECT.
If you are using create subscription with either atomic or non-atomic materialization methods and you have quoted identifiers in your replication definition, then you must alter your primary connection to allow the use of quoted identifiers.
Direct Load Materialization
When DML operations in a catch-up queue are applied to the replicate table, each insert operation is converted into a delete followed by an insert. Materialization fails when an update changes the primary key.
For direct load materialization, Replication Server selects rows from the primary table without holdlock. Thus if a row is being deleted and inserted multiple times while the selection is going on, multiple rows with the same primary key could be selected. Inserting these rows to the replicate table would cause unique index violation if there is a unique index on the replicate table. To avoid the unique index violation error, you can drop the unique index at the replicate and recreate the unique index after the subscription becomes valid. The temporary inconsistency would be resolved during the subscription catch-up time.
No Materialization
The without materialization clause specifies the no-materialization method. It provides an convenient way to create a subscription when the subscription data already exists at the replicate database.
Requirements for No Materialization
The subscription data must already exist at the replicate database.
The primary and replicate database must be in sync.
Activity must be stopped at the primary database so that there are no further updates in the Replication Server stable queue.
Using the rs_address datatype
You can subscribe to replication definitions whose columns or parameters use the special datatype <rs_address>. This datatype allows a unique subscription resolution method, whereby bitmaps of the <rs_address> datatype (based on the underlying <int> datatype) are compared with a bitmask in a subscription where clause. The bitmap comparison tells the primary Replication Server whether or not a replicate site should receive the data in each row.
where <rs_address_column1> & <bitmask >[and <rs_address_column2> & <bitmask>] [and <other_search_conditions>]
Replication Server does not replicate a row if the only changed columns are <rs_address> columns, unless the changed bits indicate that the row should be inserted or deleted at the replicate database.
Because of this filtering, <rs_address> columns in replicate databases may not be identical to the corresponding columns at the primary database. This optimizes applications that use <rs_address> columns to specify the destination replicate databases.
How the rs_address datatype works
Each bit in an <rs_address> column field may represent a category of data, such as inventory or billing. In a subscription bitmask, you set the corresponding bit to “on” (1), for each category of data you want to replicate to the subscribing site.
For example, users at a warehouse site who are interested in inventory data would set the inventory bit to “on” in a subscription bitmap. If the same warehouse users are not interested in billing data, they would set that bit to “off” (0). When a bit is set to “on” in both a subscription bitmask and an <rs_address> column, the row containing the bit is replicated.
32-Bit Limitation of Underlying int datatype for rs_address
Due to the 32-bit limitation of the underlying <int> datatype, you may need to construct primary tables with more than one <rs_address> column. The and keyword allows you to create a single subscription to perform bitmap comparisons on more than one <rs_address> column.
However, to subscribe to a row when one or more bits are set in either of two or more <rs_address> columns, you must create separate subscriptions.
Using 32-Bit Hexadecimal Numbers for rs_address
You can also specify search conditions for non-<rs_address> columns using the and keyword and the comparison operators (other than &) described in the command syntax. If you use and to specify search conditions, subscription data may not be replicated or may migrate out of a subscription, even if <rs_address> bitmap comparisons would otherwise replicate a row.
You can compare <rs_address> columns to 32-bit integer values or 32-bit hexadecimal numbers in the where clause. If you use hexadecimal numbers, pad each number with zeros, as necessary, to create an 8-digit hexadecimal value.
Be very cautious about comparing <rs_address> columns to hexadecimal numbers in the where clause of a subscription. Hexadecimal values are treated as binary strings by Adaptive Server and Replication Server. Binary strings are converted to integers by copying bytes. The resulting bit pattern may represent different integer values on different platforms.
For example, 0x0000100 represents 65,536 on platforms that consider byte 0 most significant, and represents 256 on platforms that consider byte 0 least significant. Because of these byte-ordering differences, bitmap subscriptions involving hexadecimal numbers may not work in a multi-platform replication system.
See "Datatypes" for more information about the <rs_address> and <int> datatypes. Also, see the Replication Server Administration Guide Volume 1.
Refer to the Adaptive Server Enterprise Reference Manual and the Open Client and Open Server Common Libraries Reference Manual for more information about conversion between datatypes.
Monitoring a Subscription
When Replication Server materializes a subscription, it logs in to the primary data server, using the subscription creator login name, and selects the rows from the primary table. Use check subscription to monitor the progress of the materialization.
create subscription returns a prompt before the data materialization is complete. Materialization is complete when check subscription reports “VALID” at the replicate Replication Server.
To perform database materialization for tables with timestamp columns, enable the send_timestamp_to_standby configuration parameter for the direct load connection to the primary Replication Agent, and for the connection to the replicate database.