A table can be replicated from a generic, possibly non-Virtuoso
source in an incremental fashion if the data source meets certain
The data should come from a single table.
The source table should have an explicit primary key.
There source query should have the form
SELECT fields FROM source_table WHERE scalar_conditions
A snapshot log on the source table should exist.
There should be insert, delete and update triggers on the source
table to update the snapshot log.
The incremental update is done in the following way:
All the changed records with a snaptime greater or equal from
REPL_START_TIME(SN_LAST_TS) are processed. If the record to insert
already exists, then it is updated. If the record to update does
not exist in the destination table, then it is inserted. This
contributes for conflict resolving.