Questions tagged [clickhouse]
Use this tag when referencing Yandex' ClickHouse database management system.
17 questions
0 votes
1 answer
76 views
Clickhouse - Oracle ODBC connection error
I am trying to create connection between my oracle and clickhouse databases, so I could query oracle through ch like this: SELECT * FROM odbc('DSN=OracleODBC-21', 'sys', 'test'). I have successfully ...
- 101
0 votes
0 answers
33 views
PeerDB Initial Snapshot Performance Impact on Standby PostgreSQL
I have set up a Change Data Capture (CDC) pipeline using PeerDB to mirror tables from a PostgreSQL standby read replica to ClickHouse. • The PostgreSQL database contains terabytes of data. • The ...
0 votes
1 answer
1k views
How to check user settings in ClickHouse
I have a user created by SQL command. I know there is the getSetting() function to check user settings. e.g. : SELECT getSetting('async_insert'); But how to check other users' settings if you are a ...
- 430
0 votes
0 answers
255 views
Calculate the sum of minutes between statuses Clickhouse
There is a table in ClickHouse that is constantly updated, format: date_time | shop_id | item_id | status | balance --------------------------------------------------------------- 2022-09-09 ...
- 1
-1 votes
1 answer
653 views
How to create pre-computed tables in order to speed up the query speed
One of the issues that I am encountering presently is that we have certain very large tables (>10 Million rows).When we reference these large tables or create joins, the speed of query is extremely ...
3 votes
2 answers
347 views
More efficient accumulator in SQL?
I'm writing a ledger system where every transaction can have multiple classifications. For example, if someone purchases a widget for $50, I can categorize that transaction as having an account of &...
- 141
-1 votes
1 answer
247 views
ClickHouse MV is not working perfectly as i need [closed]
I’m new to ClickHouse and having an issue with MV. I have a record table which is the data source. I’m inserting all the data here. Then created another table called adv_general_report using ...
0 votes
0 answers
60 views
How do i design a schema with proper DB engine to accumulate data depending on this need on clickhouse or in any other database?
We're a new Adtech company and I was planning to design a database where I'll pull all the data to a single table and then make new tables with a materialized views for others to generate multiple ...
1 vote
1 answer
3k views
Clickhouse OPTIMIZE performance for deduplication
I want to try and understand the performance of the OPTIMIZE query in Clickhouse. I am planning on using it to remove duplicates right after a bulk insert from a MergeTree, hence I have the options of:...
- 113
1 vote
1 answer
673 views
How to backup clickhouse over SSH?
In postgreSQL, I usually run this command to backup and compress (since my country have really low bandwidth) from server to local: mkdir -p tmp/backup ssh sshuser@dbserver -p 22 "cd /tmp; ...
- 1,403
1 vote
1 answer
2k views
Mounting Clickhouse data directory to another partition: DB::Exception: Settings profile `default` not found
I'm trying to move clickhouse data directory to another partition /dev/sdb1. So here's what I've done: sudo systemctl stop clickhouse-server mv /var/lib/clickhouse /var/lib/clickhouse-orig mkdir /var/...
- 1,403
1 vote
1 answer
2k views
Clickhouse Replication without Sharding
How to make replication (1 master, 2 slave for example) in ClickHouse without sharding? All I can see from the examples are always have sharding: Altinity Presentation Docker Compose Example ...
- 1,403
0 votes
1 answer
138 views
Is Azure Managed Disks enough to ensure high-durability for a database?
I want to set up a database in a high durability set-up on Azure. I've previously relied on DB-as-a-service offerings, but can't do that in this case, so I'd like your feedback on the plan below. Is ...
2 votes
1 answer
174 views
In what cases is using ClickHouseDb and the like a neccessity?
An open source for website analytics - https://github.com/plausible/analytics They use Postgresql and ClickHouseDb. When it comes to web analytics, there're tons of events going that need to be ...
- 23
0 votes
1 answer
2k views
Clickhouse create database structure for json data
New to clickhouse and stuck on the database creation structure for importing json data which is nested Take for example the json data that looks like the following when there is data populated "...
- 296