Lastupdate

Lastupdate is a timestamp that records the most recent modification made to a data entity in a information system. In practice, it is typically stored as a dedicated field in records (often named lastupdate or last_updated) and updated whenever the record changes. The value is usually a date-time value, commonly stored in UTC and formatted in ISO 8601 or as a database-specific timestamp type.

Purpose and usage

The lastupdate field serves several purposes. It supports data freshness checks, synchronization and replication by allowing systems to determine which records have changed since a given point in time. It aids auditing and debugging by providing a historical reference to when data last moved. It also enables incremental backups and cache invalidation, where clients fetch only altered data.

Implementation considerations

Many databases can automatically update a timestamp column on row modification through built-in features or triggers. Applications may also set or refresh the value explicitly on write. The exact data type varies (datetime, timestamp, or integer epoch), and time zone handling is important; UTC is commonly used to avoid ambiguity.

Relation to related concepts

Lastupdate is related to, but distinct from, fields like created_at (the time a record was created) and deleted_at (for soft deletes). In web contexts, the HTTP Last-Modified header serves a related purpose for conditional requests, but it is separate from internal lastupdate fields used by server-side processes.

Best practices

Use a consistent time standard (preferably UTC), document the semantics of the field, and ensure updates occur on every modification to maintain accurate data freshness signals.