Method, computer readable storage medium and computer system for obtaining snapshots of data

摘要

A method includes requesting a source database system including a source database table to record a transaction log including a plurality of transaction log entries that are representative of transactions including modifications of the source database table and to create a snapshot of the source database table during the recording of the transaction log. For each of a plurality of snapshot entries in the snapshot, one or more validity time intervals during which the snapshot entry is valid are determined on the basis of the transaction log. The snapshot entry is valid as long as it matches a corresponding entry in the source database table. A point in time at which a number of valid ones among the plurality of snapshot entries is maximum is determined. The calculated point in time is returned as an approximate value of a point in time at which the snapshot was created.

主权项

1. A method, comprising:
requesting a source database system comprising a source database table to record a transaction log comprising a plurality of transaction log entries that are representative of transactions comprising modifications of said source database table and to create a snapshot of said source database table during the recording of said transaction log; for each of a plurality of snapshot entries in said snapshot, determining, on the basis of said transaction log, one or more validity time intervals during which said snapshot entry is valid, wherein said snapshot entry is valid as long as it matches a corresponding entry in said source database table; and calculating a point in time at which a number of valid ones among said plurality of snapshot entries is maximum and returning the calculated point in time as an approximate value of a point in time at which said snapshot was created.