Algorithm to find LOB value in a relational table after key columns have been modified

摘要

A method and system for asynchronously replicating data changes in a database system captures update information for a data update in a source table from a database log, where the data value from the data update is not in the database log. A query is built to obtain the data value from the source table using the update information, including a key column value that identifies the row of the source table in which the data resides. When the key column is also updated in the same or different transaction, the data update information is stored, and the updated key column value is replaced with a later captured key column update value. The query is built and executed, and the data update is replicated at a target table. In this manner, data objects whose values are not recorded in a database log can be asynchronously replicated in a database system.