Copying data changes to a target database

A system, comprising:

• a memory for storing a computer program for copying data from a source database maintained by a first database engine to a target database maintained by a second database engine;
• and
• a processor connected to said memory, wherein said processor is configured to execute the program instructions of the computer program comprising:
• executing, by the first database engine, one or more transactions, thereby changing rows of a source table of the source database;
• assigning, by the first database engine, a data-change-ID to each changed row in the source table, the data-change-ID being indicative of the time of changing said row;
• maintaining, by the first database engine, a plurality of source pages, wherein each source page having a source-page-ID and comprising an up-to-date highest-data-change-ID, the highest-data-change-ID being the data-change-ID having been assigned most recently to one of the data rows comprised in the source page;
• creating, by the second database engine, a target table, the target table comprising a source-page-ID-column for storing, for each data row copied from the source table into the target table, the source-page-ID of the source page comprising said data row;
• maintaining, by the second database engine, a metadata table, the metadata table comprising a column for the source-page-IDs and a further column for the highest-data-change-IDs of the source pages identified by said source-page-IDs, the highest-data-change-IDs in the metadata table indicating the highest-data-change-IDs of the source pages at the time of previously copying rows of said source page to the target database;
• and
• copying data from the source table to the target table.