1. A method for managing long-lived data transactions comprising: in response to receipt of a data operation request to execute a data operation on a column of a source database, accessing a mapping that represents a correspondence between the column of the source database and a column in a temporary storage table that is configured to store one or more changes to be made to the source database; changing the temporary storage table by executing the data operation on the temporary storage table using the mapping; and after the executing, performing a reconstruction operation that reconstructs data in the source database to a particular point-in-time by, at least in part, incorporating less than all of the one or more changes to be made to the source database, using change data from the temporary storage table and source data from the source database, wherein the performing the reconstruction operation further comprises: setting search criteria to specify one or more records to be retrieved from the source table; setting sort criteria to specify order of the one or more records to be retrieved from the source table; retrieving the source data from the source database based on the search and sort criteria; reading the change data from the temporary storage table; and updating the source data from the source database with the change data from the temporary storage table.