9. A computer program product for merging documents comprising: a computer readable storage device having computer readable program code embodied therewith, the computer readable program code comprising computer readable program code configured to: receive an update document and a target document, wherein the update document and target document are document instances of a common document schema; determine whether an item of information in the update document is associated with an eligible path of the document schema in a predefined update table; generate, responsive to affirming that the item of information is associated with the eligible path, a specification of an operation by which the item of information is merged into the target document in compliance with the document schema; and apply the specified operation to the target document to produce an updated document in compliance with the document schema.
9. A computer program product for merging documents comprising: a computer readable storage device having computer readable program code embodied therewith, the computer readable program code comprising computer readable program code configured to: receive an update document and a target document, wherein the update document and target document are document instances of a common document schema; determine whether an item of information in the update document is associated with an eligible path of the document schema in a predefined update table; generate, responsive to affirming that the item of information is associated with the eligible path, a specification of an operation by which the item of information is merged into the target document in compliance with the document schema; and apply the specified operation to the target document to produce an updated document in compliance with the document schema. 14. The computer program product of claim 9 , wherein the computer readable program code is further configured to: determine whether each of a plurality of items of information in the update document is associated with a corresponding eligible path of the document schema in the update table; generate, for the items of information associated with the eligible path in the update table, respective specifications of operations by which the items of information are merged into the target document in compliance with the document schema; and apply the plurality of specified operations to the target document to produce an updated document in compliance with the document schema.