questdb | open source time-series database | Time Series Database library
kandi X-RAY | questdb Summary
kandi X-RAY | questdb Summary
QuestDB is a high-performance, open-source SQL database for applications in financial services, IoT, machine learning, DevOps and observability. It includes endpoints for PostgreSQL wire protocol, high-throughput schema-agnostic ingestion using InfluxDB Line Protocol, and a REST API for queries, bulk imports, and exports. QuestDB implements ANSI SQL with native extensions for time-oriented language features. These extensions make it simple to correlate data from multiple sources using relational and time series joins. QuestDB achieves high performance from a column-oriented storage model, massively-parallelized vector execution, SIMD instructions, and various low-latency techniques. The entire codebase was built from the ground up in Java and C++, with no dependencies, and is 100% free from garbage collection.
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Top functions reviewed by kandi - BETA
- Returns the initial seed value .
- Assemble the parse method invocation .
- Generate table query .
- assembles a RecordToRowCopier
- Publish multiple copy tasks .
- Sorts the elements in sorted sequence .
- Commit o3 .
- Rewrite select clause .
- Format time in milliseconds .
- Create a function .
questdb Key Features
questdb Examples and Code Snippets
Lines of Code : 22License : Non-SPDX (Apache License 2.0)
Copypackage com.example.sender;
import io.questdb.client.Sender;
public class AuthTlsExample {
public static void main(String[] args) {
try (Sender sender = Sender.builder()
.address("clever-black-363-c1213c97.ilp.b04c.quest package com.example.sender;
import io.questdb.client.Sender;
public class AuthExample {
public static void main(String[] args) {
// Replace:
// 1. "localhost:9000" with a host and port of your QuestDB server
// 2. "testU package com.example.sender;
import io.questdb.client.Sender;
public class BasicExample {
public static void main(String[] args) {
try (Sender sender = Sender.builder().address("localhost:9009").build()) {
sender.table("inven Community Discussions
Trending Discussions on questdb
QUESTION
What is a equivalent of a merge query(insert/update/delete) is present in the QuestDB?
Below is an example for tsql. I would like to understand how to implement the same logic in QuestDB - insert rows for new data and update rows for existing data (if they changed)
https://www.sqlshack.com/understanding-the-sql-merge-statement/ USE SqlShackMergeDemo GO
...ANSWER
Answered 2022-Feb-11 at 09:52QuestDB (current v6.2) does not support any form UPDATE or DELETE statements at the moment. The only way to delete data is to drop a partition or truncate table. There is no equivalent for MERGE either.
This is going to change soon.
QUESTION
I'm working on a price data project, trying to store OHLC 1 minute data and then sampling it over various intervals. I decided to try QuestDB for its neat time-series features such as SAMPLE BY but am running into a wall.
I want to use SAMPLE BY to query my data, which looks like this:
For example, for the two rows above, which are in the same month, I would like to run SAMPLE BY 1M and aggregate the values for the month.
For high and low values the aggregate functions are min(low) and max(high), but I can't figure out what to do for open and close values.
I tried retrofitting this approach but got as far as the following without errors:
...ANSWER
Answered 2022-Jan-05 at 00:11It will be first() and last() to get open and close.
QUESTION
Let's imagine that I have the following data on a QuestDB table:
...ANSWER
Answered 2021-Dec-10 at 21:14You can do with left join
QUESTION
OS: Ubuntu 20.04.3 LTS Java: openjdk version "17" 2021-09-14 | OpenJDK Runtime Environment (build 17+35-2724) Library: implementation group: 'org.questdb', name: 'questdb', version: '6.0.9'
Whenever I am trying to run the sample it produces this error:
...ANSWER
Answered 2021-Oct-26 at 09:40QuestDB v6.0.9 (and previous) does not run on Java 17. Only Java 11 or 8 supported
QUESTION
I am new to questdb. To check if tables contain designated timestamp column we can either use tables() or table_columns(). If this is the case then what is the difference between both.
...ANSWER
Answered 2021-Oct-22 at 12:21To query column you can use either
QUESTION
With the new addition of the geohash type in update 6.0.5, has the performance improved? Specifically, will this improve performance for weather / geospatial data ingestion relative to previous Questdb iterations?
ANSWER
Answered 2021-Oct-22 at 11:31Addition of geohashes means that there is a new type for this kind of data. If you are using existing types for weather data, there will be no change in performance. There are internal improvements which make working with the geohash type more efficient than storing these values as strings of symbols, for example.
For more info, see the geohash documentation at https://questdb.io/docs/concept/geohashes/
QUESTION
When I run QuestDB selects for few tables I started see the error
Invalid metadata version at fd=34. Metadata version does not match runtime version
I am running QuestDB docker image questdb/questdb:6.0.4 and I believe I created the table when I used questdb/questdb:6.0.5. Is it possible to downgrade tables in QuestDB or any other way to fix the error?
ANSWER
Answered 2021-Oct-07 at 10:24It is possible to downgrade from some version to others, but not always.
In particular 6.0.5 can be downgraded to 6.0.4. To do it, in every table directory upgrade process leaves file _meta.v419. You need to stop questdb, delete _meta and rename _meta.v419 into _meta. Then you delete dbroot/upgrade.d and start QuestDB.
QUESTION
I’m new to QuestDB, and I‘m wondering if there’s an npm package for it. I can see an npmjs.com/questdb package, but it doesn’t seem to have any data in it. Please tell me if there is. Thanks!
...ANSWER
Answered 2021-Oct-07 at 08:55This is an empty placeholder package added by one of QuestDB team members.
As of now QuestDB does not have dedicated JS client (as in fact no dedicated clients in any other programming language). It relies mostly on compatibility with Postgres Driver as well as well as platform specific REST clients with CSV, JSON serialisations.
QuestDB also accepts messages in Influx Line Protocol serialisation format but unlike InfluxDB itself instead of HTTP it uses TCP transport. It makes sense to add NodeJS client with ILP serialisation and TCP transport and that will be QuestDB JS client then.
QUESTION
When working with regular SQL databases, indexes are useful for fetching a few rows, but not so useful when you are fetching a large amount of data from a table. For example, imagine you have a table with stock valuations of 10 stocks over time:
...ANSWER
Answered 2021-Sep-22 at 15:55A column per stock is not easy to achieve in QuestDB. If you create table like this
QUESTION
I am building a solution that uses Mosquitto for brokering IoT sensor data. The IoT sensors are publishing to MQTT topics and I would like to store the payload data in QuestDB for analysis, what are some options for using this as storage.
...ANSWER
Answered 2021-Aug-30 at 12:50One of the easiest and fastest ways of ingesting data from MQTT topics into QuestDB is to use Telegraf to stream records via InfluxDB line protocol. The configuration for Telegraf would look something like the following:
Community Discussions, Code Snippets contain sources that include Stack Exchange Network
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No vulnerabilities reported
Install questdb
You can use questdb like any standard Java library. Please include the the jar files in your classpath. You can also use any IDE and you can run and debug the questdb component as you would do with any other Java program. Best practice is to use a build tool that supports dependency management such as Maven or Gradle. For Maven installation, please refer maven.apache.org. For Gradle installation, please refer gradle.org .
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