Erik Nordström 202692f1ef Make tests use the new continuous aggregate API
Tests are updated to no longer use continuous aggregate options that
will be removed, such as `refresh_lag`, `max_interval_per_job` and
`ignore_invalidation_older_than`. `REFRESH MATERIALIZED VIEW` has also
been replaced with `CALL refresh_continuous_aggregate()` using ranges
that try to replicate the previous refresh behavior.

The materializer test (`continuous_aggregate_materialize`) has been
removed, since this tested the "old" materializer code, which is no
longer used without `REFRESH MATERIALIZED VIEW`. The new API using
`refresh_continuous_aggregate` already allows manual materialization
and there are two previously added tests (`continuous_aggs_refresh`
and `continuous_aggs_invalidate`) that cover the new refresh path in
similar ways.

When updated to use the new refresh API, some of the concurrency
tests, like `continuous_aggs_insert` and `continuous_aggs_multi`, have
slightly different concurrency behavior. This is explained by
different and sometimes more conservative locking. For instance, the
first transaction of a refresh serializes around an exclusive lock on
the invalidation threshold table, even if no new threshold is
written. The previous code, only took the heavier lock once, and if, a
new threshold was written. This new, and stricter locking, means that
insert processes that read the invalidation threshold will block for a
short time when there are concurrent refreshes. However, since this
blocking only occurs during the first transaction of the refresh
(which is quite short), it probably doesn't matter too much in
practice. The relaxing of locks to improve concurrency and performance
can be implemented in the future.
2020-09-11 16:07:21 +02:00
2020-06-02 23:48:35 +02:00
2019-02-05 16:55:16 -05:00
2020-04-21 11:47:47 +02:00
2020-09-07 17:44:53 +02:00
2020-09-01 14:49:30 +02:00
2018-09-10 13:29:59 -04:00
2020-09-08 19:57:41 +02:00
2020-02-29 15:38:36 -05:00
2020-09-08 19:57:41 +02:00

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Build Status Linux/macOS Build Status Linux i386 Windows build status Coverity Scan Build Status Code Coverage

TimescaleDB

TimescaleDB is an open-source database designed to make SQL scalable for time-series data. It is engineered up from PostgreSQL and packaged as a PostgreSQL extension, providing automatic partitioning across time and space (partitioning key), as well as full SQL support.

Timescale Cloud is our fully managed, hosted version of TimescaleDB, available in the cloud of your choice (pay-as-you-go, with free trial credits to start). To determine which option is best for you, see Timescale Products for more information about our Apache-2 version, TimescaleDB Community (self-hosted) and Timescale Cloud (hosted), including: feature comparisons, FAQ, documentation, and support.

Below is an introduction to TimescaleDB. For more information, please check out these other resources:

For reference and clarity, all code files in this repository reference licensing in their header (either Apache License, Version 2.0 or Timescale License (TSL)). Apache-2 licensed binaries can be built by passing -DAPACHE_ONLY=1 to bootstrap.

Contributors welcome.

(To build TimescaleDB from source, see instructions in Building from source.)

Using TimescaleDB

TimescaleDB scales PostgreSQL for time-series data via automatic partitioning across time and space (partitioning key), yet retains the standard PostgreSQL interface.

In other words, TimescaleDB exposes what look like regular tables, but are actually only an abstraction (or a virtual view) of many individual tables comprising the actual data. This single-table view, which we call a hypertable, is comprised of many chunks, which are created by partitioning the hypertable's data in either one or two dimensions: by a time interval, and by an (optional) "partition key" such as device id, location, user id, etc. (Architecture discussion)

Virtually all user interactions with TimescaleDB are with hypertables. Creating tables and indexes, altering tables, inserting data, selecting data, etc., can (and should) all be executed on the hypertable.

From the perspective of both use and management, TimescaleDB just looks and feels like PostgreSQL, and can be managed and queried as such.

Before you start

PostgreSQL's out-of-the-box settings are typically too conservative for modern servers and TimescaleDB. You should make sure your postgresql.conf settings are tuned, either by using timescaledb-tune or doing it manually.

Creating a hypertable

-- Do not forget to create timescaledb extension
CREATE EXTENSION timescaledb;

-- We start by creating a regular SQL table
CREATE TABLE conditions (
  time        TIMESTAMPTZ       NOT NULL,
  location    TEXT              NOT NULL,
  temperature DOUBLE PRECISION  NULL,
  humidity    DOUBLE PRECISION  NULL
);

-- Then we convert it into a hypertable that is partitioned by time
SELECT create_hypertable('conditions', 'time');

Inserting and querying data

Inserting data into the hypertable is done via normal SQL commands:

INSERT INTO conditions(time, location, temperature, humidity)
  VALUES (NOW(), 'office', 70.0, 50.0);

SELECT * FROM conditions ORDER BY time DESC LIMIT 100;

SELECT time_bucket('15 minutes', time) AS fifteen_min,
    location, COUNT(*),
    MAX(temperature) AS max_temp,
    MAX(humidity) AS max_hum
  FROM conditions
  WHERE time > NOW() - interval '3 hours'
  GROUP BY fifteen_min, location
  ORDER BY fifteen_min DESC, max_temp DESC;

In addition, TimescaleDB includes additional functions for time-series analysis that are not present in vanilla PostgreSQL. (For example, the time_bucket function above.)

Installation

TimescaleDB is available pre-packaged for several platforms:

Timescale Cloud (database-as-a-service) is available via free trial. You create database instances in the cloud of your choice and use TimescaleDB to power your queries, automating common operational tasks and reducing management overhead.

We recommend following our detailed installation instructions.

To build from source, see instructions here.

Resources

Useful tools

  • timescaledb-tune: Helps set your PostgreSQL configuration settings based on your system's resources.
  • timescaledb-parallel-copy: Parallelize your initial bulk loading by using PostgreSQL's COPY across multiple workers.

Additional documentation

Community & help

Releases & updates

Contributing

Description
An open-source time-series SQL database optimized for fast ingest and complex queries. Packaged as a PostgreSQL extension.
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