November 8, 2017
Hot Alter Table Sizzles
New feature relaxes schema’s rigidness to reduce update complexity and significantly reduces downtime
Let’s face it. Schema changes in a database can cause problems for everyone – from the developer to the administrator and down the line to the end user. Schema changes are often unavoidable, cumbersome and consume time and money with extremely long downtimes for clients and customers waiting for file conversions to complete. … That is, until now.
One of c-treeACE V11.5’s new features is Hot Alter Table – a new function that allows users to perform schema changes with minimal interruption to database operations, as well as nominal downtime for the applications. Hot Alter Table allows easily managed “rolling upgrades” to products deployed in the field. This is done by automatically delaying updating records until the first time it’s written, making an Alter Table virtually instantaneous because only the underlying metadata for the data file is being updated at upgrade time. The result is that the time to update a table (regardless of size) can be reduced from hours to minutes; minutes to seconds.
Hot Alter Table allows administrators to enjoy reduced effort and customers to experience significantly less downtime because of the ability to convert schema changes “on-the-fly.” An example of this is when someone is reading a record that has not been updated to the current schema, it is converted on-the-fly via Hot Alter Table to make it appear current. This can occur because the table’s metadata contains the record converters necessary to convert records to each version of the schema, and the current schema version is always presented back to the reader, regardless of the version stored on disk. When the record is written to disk, it is always updated to the most recent schema versions.
The end result of using Hot Alter Table is increased efficiency and minimal impact to business operations due to downtime. These benefits are complemented and enhanced by the other new performance features in c-treeACE V11.5. Detailed information about Hot Alter Table and other exciting c-treeACE V11.5 features are available at faircom.com/v11-5-is-here.