RepAgent
for Adaptive Server uses Log Transfer Language (LTL) to specify a table or column name that
may be quoted, and whether a table column is part of the table primary key. Since RepAgent
sends the primary key and quoted identifier information to Replication Server, you do not
need a replication definition if the sole purpose of the replication definition is to
specify primary key and quoted identifier information, in a replication system that contains
only Adaptive Server databases.
The reduced requirement for replication definitions makes it easier to manage a
replication environment involving databases with many tables, tables with many columns,
or tables with frequent schema changes. Replication performance improves for tables that
are currently without replication definitions, as RepAgent directly provides Replication
Server with table primary-key information, so that Replication Server packs only the
primary-key columns in the
where clauses of
update,
delete, and
select commands.
- When a replication definition is subscribed by an MSA database, its primary key
columns are used for the where clause packing for the
database.
- When a replication definition is marked send standby replication
definition columns or send standby all columns,
primary-key columns of the replication definition are used for the
where clause packing for the standby and the MSA
databases that do not have a subscription to any of the replication definitions
of the same table.
- When there are one or more replication definitions for a table, and none of them
are marked send standby, Replication Server uses the union of
the primary key columns for the replication definitions for the
where clause packing for the standby and MSA databases
that do not have subscriptions to any of the replication definitions for the
table.
- When there is no replication definition for a table, and LTL sends information
about the primary key, the primary key columns indicated by the LTL are used for
the where clause packing.
- When there is no replication definition for a table, and an LTL command does not
indicate any primary column, all columns except text,
image, and unitext columns are used for
the where clause packing.
See Replication Server Administration Guide Vol 2 > Manage Warm Standby
Applications.
Quoted Table and Column Names and Replication Definitions
When Replication Server packs a DML command for the target database, and if there are
one or more replication definitions for the table, Replication Server decides that a
table or column name should be quoted according to a replication definition if the
replication definition is:
- Subscribed by a MSA database.
- Marked send standby [ replication definition | all ]
columns for MSA databases that do not have subscriptions to a
replication definition.
- Marked send standby replication definition columns for
the standby database.
Otherwise,
Replication Server packs a table or column name according to the LTL.
System Requirements
RepAgent sends primary-key and quoted identifier
information only with LTL version 740 or later, which is supported by Adaptive Server
15.7 and later, and Replication Server 15.7 and later.