About Timescale hyperfunctions

Timescale hyperfunctions are a specialized set of functions that allow you to analyze time-series data. You can use hyperfunctions to analyze anything you have stored as time-series data, including IoT devices, IT systems, marketing analytics, user behavior, financial metrics, and cryptocurrency.

Hyperfunctions allow you to perform critical time-series queries quickly, analyze time-series data, and extract meaningful information. They aim to identify, build, and combine all of the functionality SQL needs to perform time-series analysis into a single extension.

Some hyperfunctions are included in the default TimescaleDB product. For additional hyperfunctions, you need to install the Timescale Toolkit PostgreSQL extension.

Hyperfunctions available with TimescaleDB and Timescale Toolkit

Here is a list of all the hyperfunctions provided by Timescale. Hyperfunctions marked ‘Toolkit’ require an installation of Timescale Toolkit. Hyperfunctions marked ‘experimental’ are still under development.

warning

Experimental features could have bugs. They might not be backwards compatible, and could be removed in future releases. Use these features at your own risk, and do not use any experimental features in production.

Approximate count distinct functions

Hyperfunction type Hyperfunction name Toolkit Experimental
hyperloglog() functions
Aggregate hyperloglog() ✅
Alternate aggregate approx_count_distinct() ✅ ✅
Accessor distinct_count() ✅
stderror() ✅
Rollup rollup() ✅

Downsample functions

Hyperfunction type Hyperfunction name Toolkit Experimental
One step aggregate asap_smooth() ✅
gp_lttb() ✅ ✅
lttb() ✅

Financial analysis functions

Hyperfunction type Hyperfunction name Toolkit Experimental
candlestick_agg() functions
Aggregate candlestick_agg() ✅ ✅
Pseudo aggregate candlestick() ✅ ✅
Accessor close() ✅ ✅
close_time() ✅ ✅
high() ✅ ✅
high_time() ✅ ✅
low() ✅ ✅
low_time() ✅ ✅
open() ✅ ✅
open_time() ✅ ✅
volume() ✅ ✅
vwap() ✅ ✅
Rollup rollup() ✅ ✅
ohlc() functions
Aggregate ohlc() ✅ ✅
Accessor close() ✅ ✅
close_time() ✅ ✅
high() ✅ ✅
high_time() ✅ ✅
low() ✅ ✅
low_time() ✅ ✅
open() ✅ ✅
open_time() ✅ ✅
Rollup rollup() ✅ ✅

Frequency analysis functions

Hyperfunction type Hyperfunction name Toolkit Experimental
count_min_sketch() functions
Aggregate count_min_sketch() ✅ ✅
Accessor approx_count() ✅ ✅
freq_agg() functions
Aggregate freq_agg() ✅ ✅
Accessor into_values() ✅ ✅
min_frequency(), max_frequency() ✅ ✅
topn_agg() functions
Aggregate topn_agg() ✅ ✅
Accessor into_values() ✅ ✅
min_frequency(), max_frequency() ✅ ✅
topn() ✅ ✅

Gapfilling and interpolation functions

Hyperfunction type Hyperfunction name Toolkit Experimental
Bucket time_bucket_gapfill()
Interpolator interpolate()
locf()

Metric aggregation functions

Hyperfunction type Hyperfunction name Toolkit Experimental
counter_agg() functions
Aggregate counter_agg() ✅
Accessor corr() ✅
counter_zero_time() ✅
delta() ✅
extrapolated_delta() ✅
extrapolated_rate() ✅
first_time(), last_time() ✅
first_val(), last_val() ✅
idelta_left(), idelta_right() ✅
intercept() ✅
interpolated_delta() ✅ ✅
interpolated_rate() ✅ ✅
irate_left(), irate_right() ✅
num_changes() ✅
num_elements() ✅
num_resets() ✅
rate() ✅
slope() ✅
time_delta() ✅
Rollup rollup() ✅
Mutator with_bounds() ✅
gauge_agg() functions
Aggregate gauge_agg() ✅ ✅
Accessor corr() ✅
delta() ✅
extrapolated_delta() ✅
extrapolated_rate() ✅
idelta_left(), idelta_right() ✅
intercept() ✅
interpolated_delta() ✅ ✅
interpolated_rate() ✅ ✅
irate_left(), irate_right() ✅
num_changes() ✅
num_elements() ✅
rate() ✅
slope() ✅
time_delta() ✅
Rollup rollup() ✅
Mutator with_bounds() ✅

Minimum and maximum functions

Hyperfunction type Hyperfunction name Toolkit Experimental
max_n() functions
Aggregate max_n() ✅ ✅
Accessor into_array() ✅ ✅
into_values() ✅ ✅
Rollup rollup() ✅ ✅
max_n_by() functions
Aggregate max_n_by() ✅ ✅
Accessor into_values() ✅ ✅
Rollup rollup() ✅ ✅
min_n() functions
Aggregate min_n() ✅ ✅
Accessor into_array() ✅ ✅
into_values() ✅ ✅
Rollup rollup() ✅ ✅
min_n_by() functions
Aggregate min_n_by() ✅ ✅
Accessor into_values() ✅ ✅
Rollup rollup() ✅ ✅

Percentile approximation functions

Hyperfunction type Hyperfunction name Toolkit Experimental
tdigest() functions
Aggregate tdigest() ✅
Accessor approx_percentile() ✅
approx_percentile_rank() ✅
mean() ✅
num_vals() ✅
Rollup rollup() ✅
uddsketch() functions
Aggregate uddsketch() ✅
Accessor approx_percentile() ✅
approx_percentile_array() ✅ ✅
approx_percentile_rank() ✅
error() ✅
mean() ✅
num_vals() ✅
Alternate aggregate percentile_agg() ✅
Rollup rollup() ✅

Saturating math functions

Hyperfunction type Hyperfunction name Toolkit Experimental
One step operation saturating_add() ✅ ✅
saturating_add_pos() ✅ ✅
saturating_mul() ✅ ✅
saturating_sub() ✅ ✅
saturating_sub_pos() ✅ ✅

State aggregates functions

Hyperfunction type Hyperfunction name Toolkit Experimental
heartbeat_agg() functions
Aggregate heartbeat_agg() ✅ ✅
Accessor dead_ranges() ✅ ✅
downtime() ✅ ✅
interpolate() ✅ ✅
interpolated_downtime() ✅ ✅
interpolated_uptime() ✅ ✅
live_at() ✅ ✅
live_ranges() ✅ ✅
uptime() ✅ ✅
Rollup rollup() ✅ ✅
state_agg() timeline_agg() functions
Aggregate state_agg(), timeline_agg() ✅ ✅
Accessor duration_in() ✅ ✅
interpolated_duration_in() ✅ ✅
interpolated_state_periods() ✅ ✅
interpolated_state_timeline() ✅ ✅
into_values() ✅ ✅
rollup() ✅ ✅
state_periods() ✅ ✅
state_timeline() ✅ ✅

Statistical and regression analysis functions

Hyperfunction type Hyperfunction name Toolkit Experimental
stats_agg() (one variable) functions
Aggregate stats_agg() (one variable) ✅
Accessor kurtosis() ✅
num_vals() ✅
skewness() ✅
stddev() ✅
sum() ✅
variance() ✅
average() ✅
Rollup rolling() ✅
rollup() ✅
stats_agg() (two variables) functions
Aggregate stats_agg() (two variables) ✅
Accessor average_y(), average_x() ✅
corr() ✅
covariance() ✅
determination_coeff() ✅
intercept() ✅
kurtosis_y(), kurtosis_x() ✅
num_vals() ✅
skewness_y(), skewness_x() ✅
slope() ✅
stddev_y(), stddev_x() ✅
sum_y(), sum_x() ✅
variance_y(), variance_x() ✅
x_intercept() ✅
Rollup rolling() ✅
rollup() ✅

Time weighted calculations functions

Hyperfunction type Hyperfunction name Toolkit Experimental
time_weight() functions
Aggregate time_weight() ✅
Accessor average() ✅
first_time() ✅
first_val() ✅
integral() ✅ ✅
interpolated_average() ✅ ✅
interpolated_integral() ✅ ✅
last_time() ✅
last_val() ✅
Rollup rollup() ✅

General functions

Hyperfunction type Hyperfunction name Toolkit Experimental
Bucket time_bucket()
timescaledb_experimental.time_bucket_ng() ✅
One step aggregate approximate_row_count()
first()
histogram()
last()
One step operation days_in_month() ✅ ✅
month_normalize() ✅ ✅

For more information about each of the API calls listed in this table, see our hyperfunction API documentation.

Function pipelines

Function pipelines are an experimental feature, designed to radically improve the developer ergonomics of analyzing data in PostgreSQL and SQL, by applying principles from functional programming and popular tools like Python’s Pandas, and PromQL.

SQL is the best language for data analysis, but it is not perfect, and at times can get quite unwieldy. For example, this query gets data from the last day from the measurements table, sorts the data by the time column, calculates the delta between the values, takes the absolute value of the delta, and then takes the sum of the result of the previous steps:

2. SELECT device id,

4. sum(abs_delta) as volatility

6. FROM (

8. SELECT device_id,

10. abs(val - lag(val) OVER last_day) as abs_delta

12. FROM measurements

14. WHERE ts >= now()-'1 day'::interval) calc_delta

16. GROUP BY device_id;

You can express the same query with a function pipeline like this:

2. SELECT device_id,

4. timevector(ts, val) -> sort() -> delta() -> abs() -> sum() as volatility

6. FROM measurements

8. WHERE ts >= now()-'1 day'::interval

10. GROUP BY device_id;

Function pipelines are completely SQL compliant, meaning that any tool that speaks SQL is able to support data analysis using function pipelines.

For more information about how function pipelines work, read our blog post.

Toolkit feature development

Timescale Toolkit features are developed in the open. As features are developed they are categorized as experimental, beta, stable, or deprecated. This documentation covers the stable features, but more information on our experimental features in development can be found in the Toolkit repository.

Contribute to Timescale Toolkit

We want and need your feedback! What are the frustrating parts of analyzing time-series data? What takes far more code than you feel it should? What runs slowly, or only runs quickly after many rewrites? We want to solve community-wide problems and incorporate as much feedback as possible.