Use direct load materialization to materialize data between different
kinds of primary and replicate databases.
Direct load materialization
differs from other automatic materialization methods:
- No materialization queue is used with direct load materialization. Data is
loaded directly from a primary table into a replicate table.
- Replication to other tables is not suspended during direct load materialization.
DML operations on a primary table being materialized are stored in a catch-up
queue and applied to the replicate table after the initial materialization
phase. DML operations on a primary table that is not being materialized are
replicated into the replicate table as the DSI receives them. Multiple tables
can be concurrently materialized with direct load materialization.
- When subscription materialization stops due to an error, regular replication to
other tables is not suspended.
- Multiple parallel threads can be used to load data from one primary table to its
corresponding replicate table. You can tune this multi-threaded behavior with
max_mat_load_threads.
The atomic and nonatomic materialization methods described here are only
supported for an Adaptive Server primary. For an explanation of the different types and
methods of materialization, see the
Replication Server Heterogeneous Replication
Guide > Materialization > Types of Materialization and the
Replication
Server Administration Guide: Volume 1 > Manage Subscriptions > Subscription
Materialization Methods.
Direct load materialization can be used to materialize data:
Note: Direct load materialization is not supported for
materializing data into an Adaptive Server database.
Restrictions and Limitations for create subscription
- When the direct_load option is used, no other
subscription can be created or defined at the same time for the same
replicate table.
- The direct_load option is for subscriptions to table
replication definitions only and is used with without
holdlock. It cannot be used with without
materialization or
incrementally.
- The user and password options are used
only with direct_load.
- You can only use the
direct_load option against a physical database
connection, not an alternate or logical connection. This is the case for
both the primary connection—the connection specified in the replication
definition—and the replicate connection—the connection specified in the
subscription.
- The maintenance user of the primary database cannot be used in the
user and password options to
create subscriptions.
- You cannot use atomic materialization if the primary database is not
Adaptive Server. For a primary database other than Adaptive Server, the only
automatic materialization option supported is direct load.You cannot drop a
subscription with the with purge option if the replicate
database is not Adaptive Server.
- The direct_load option is available only if the replicate
Replication Server site version and route version are 1571100 or later.
- You can use row filtering, name mapping, customized function strings and
datatype mapping with subscriptions created using the
direct_load option.
- Replication Server rejects any attempt to create a subscription with the
direct_load option if the number of subscriptions
being created has reached or exceeded
num_concurrent_subs.