`current_timestamp`
Generic Description
Returns the current timestamp. It is documented separately because time construction, sequence ordering, window parameters, and as-of behavior materially change analytical meaning.
Simple example:
RETURN current_timestamp() AS value
Consumer-Level Explanation
Use it for live as-of calculations and freshness expressions. Prefer this function when the temporal assumption should be visible to the planner, especially for event streams, freshness checks, and sequence features.
More Detailed Explanation
current_timestamp belongs to the temporal construction, conversion, or extraction surface. Use it to make time semantics explicit in the query text: whether a value is date-only, time-only, timestamp-like, duration-like, current-time dependent, or bucketed to a chosen calendar unit.
Advanced Example
This example names the event stream and operational context before applying current_timestamp, which helps planner tooling preserve the intended sequence semantics.
WITH 'sensor-1' AS subject_id,
[{ts: 1735689600000, value: 10.0, state: 'ok'}, {ts: 1735689660000, value: 13.0, state: 'ok'}, {ts: 1735689840000, value: 9.0, state: 'warn'}, {ts: 1735690200000, value: 16.0, state: 'ok'}] AS readings
RETURN subject_id,
current_timestamp() AS value
Real Use Cases
- time-bucketed graph analytics
- as-of filtering and event-window construction
- making imported timestamp strings or epoch values typed before comparison
Real Limitations And Tradeoffs
- current-time functions are intentionally nondeterministic
- timezone and local-time choices should be made explicit when results cross systems
- extractors and truncation functions do not create temporal history; they only transform values already in the row