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Delayed DDL Propagation Disclosure Number: IPCOM000237944D
Publication Date: 2014-Jul-23
Document File: 3 page(s) / 32K

Publishing Venue

The Prior Art Database


Disclosed is a method for delayed Distributed Descriptions Logics (DDL) propagation for the implementation of schema changes across multiple servers.

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Delayed DDL Propagation

Embodiments of the present invention disclosed herein enable customers to make schema changes, test those changes, and then easily deploy those changes over a multitude of servers. An example of such is a deployment in a retail store chain.

Likewise, systems administrators may automatically propagate schema changes, including automatic replication adjustments to support those schema changes. Further, embodiments of the present invention enable administrators to do a rolling application upgrade wherein changes are made one node at a time and then new applications (apps) are started, likewise, one upgraded node at a time, which causes the propagation of the Distributed Descriptions Logics (DDL) changes, auto replication metadata adjustment and resynchronization of data changes that might have been done during the transaction.

It is possible to manually perform schema changes on each node. That approach is not conducive to automatic adjustments for replication metadata. This functionality enables the user to defer the propagation of the DDL operations and control when those operations are propagated.

Also, flexible grid technology exists, as shown in Figure 1, that can propagate DDL operations to the servers in the grid. This means, for instance, that a command such as CREATE TABLE executed on one node within the grid is propagated and executed on all of the nodes within the grid.

Figure 1: Current process for DDL propagation

According to embodiments of the present invention, in contrast the CREATE TABLE


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command propagation is delayed subject to user control, so that DDL changes can be tested with the application. Only after testing the DDL changes on one server are changes propagated to the other nodes within the grid.

Referring now to Figure 2, internal logic for DDL execution is depicted according to embodiments of the present invention. In the DDL execution code within the server, the di...