Start Explain what the open dating system is

Explain what the open dating system is

query optimizer relies on up-to-date statistics for tables, schemas, and the database.

Time measurement units are counted from the epoch so that the date and time of events can be specified unambiguously.

How often you update statistics depends on how often your data changes.

recommends that you schedule statistics analysis on a regular basis.

Epochs are generally chosen to be convenient or significant by a consensus of the time scale's initial users, or by authoritarian fiat.