Citus is a distributed database that lets you run SQL queries over very large data sets.
Citus is a distributed database that lets you run SQL queries over very large data sets. https://github.com/citusdata/citus
Questions tagged [citus]
131 questions
5
votes
1 answer
Can I change the distribution method on an existing Citus table?
During a migration from MySQL into a Citus cluster, I used the range distribution method. The migration is complete, but now I'd like to change the distribution method to hash.
Is there a way to change the distribution method from range to hash for…
Eugen Konkov
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4
votes
1 answer
Primary Keys (UUID, Sequence) strategy on Citus
What is the best approach for primary keys on Citus?
UUID:
No lock required, as opposed to the Identity/Serial. But expensive in storage and eventually on queries + causes fragmentations.
Sequence - Identity
Causes a bottleneck while creating an…
Tomer Peled
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4
votes
1 answer
How do I distributed a table using values from multiple columns?
Acording to the Citus documentation, it's easy to distribute a table using a single column:
SELECT master_create_distributed_table('github_events', 'created_at', 'append');
Is there a way to distribute a table using multiple columns? For example,…
Eugen Konkov
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4
votes
1 answer
Does Citus support creating shards using mysql_fdw?
The Citus documentation for the master_get_table_metadata function states:
part_storage_type: Type of storage used for the table. May be ‘t’ (standard table), ‘f’ (foreign table) or ‘c’ (columnar table).
But I searched the entire documentation and…
Eugen Konkov
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3
votes
1 answer
Citus shard rebalancing does not progress
I have a Citus cluster with 3 worker nodes, added a new worker recently then started a rebalance on a table. Everything is OK until here but rebalancing does not end. When I look at get_rebalance_progress() target shard size is always %10 of source…
Kellad
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3
votes
1 answer
citus rebalance_table_shards() -> fe_sendauth: no password supplied
Version: postgresql 14 and citus 10.2
When I execute
select rebalance_table_shards('tbl_name');
in the CN node, postgresql gives an error message: ERROR: connection to the remote node localhost:5432 failed with the following error: fe_sendauth: no…
William Que
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- 4
3
votes
3 answers
AWS DMS Task failed with error: Error executing source loop; Stream component failed at subtask 0
I want to migrate my PostgresDB hosted in Citus cloud service to AWS RDS Aurora Postgres.
I am using AWS DMS service. Have created task but getting following errors:
Last failure message Last Error Stream Component Fatal error. Task
error…
Ashish Karpe
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3
votes
1 answer
Access \set variables in psql for Postgres function bodies
I am creating a generic automated Postgres script which includes DDL, DML, functions and triggers. I have achieved to parameterize the schema name with \set in psql in most of the operation but it's not working in case of function bodies. I've…
Ankur Mahajan
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3
votes
1 answer
CitusDB: modifying the partition value of rows is not allowed
i want to update or delete data on the test database use citus based on postgressql, it note me this info:
modifying the partition value of rows is not allowed
citus:6.0
postgresql:9.6
how can i udpate or delete data when i use citus?
Chan
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- 2
3
votes
1 answer
How do I restore a database dump to a Citus cluster?
While restoring a (pg_dump-produced) database dump, I get the following error:
Cannot execute COPY FROM on a distributed table on master node
How can I work around this?
user2724057
3
votes
2 answers
Why does Citus error with certain boolean constraints?
If I run this query:
SELECT "t1"."id" FROM "session" AS t1 WHERE ("t1"."dirty" = TRUE) ORDER BY "t1"."id" LIMIT 1000;
I get the following error:
Error : ERROR: unsupported clause type
This query works perfectly on a local table. Why is Citus…
digi604
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3
votes
1 answer
How to add index to CitusDB's cstore_fdw?
I'm currently building an OLAP database in postgres and want to compare the performance of a column-store vs row-store database. CitusDB open-sourced its columnar-store extension cstore_fdw so I'm comparing database performance with and without…
TheGrimmScientist
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2
votes
1 answer
How can I stop an active query on a postgres coordinator when the worker node has crashed
I have a postgres select query that can not be stopped using the standard pg_cancel/pg_terminate commands.
Both commands return true, but do nothing.
The query has access share locks on hundreds of tables, making it impossible for our ETL's to…
johnfensterman
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- 1
2
votes
1 answer
Cannot create distributed table with foreign key on Citus 11.1
I want to migrate from Citus 11.0 to 11.1.
I'm using the docker-compose file from Citus' github.
The following script works fine on 11.0, but not on 11.1:
create table tmp_table1 (
id varchar(36) not null,
tenant_key varchar(36) not null,
…
Alexis Hassler
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2
votes
1 answer
Citus sharding, replication, and replication
I setup the citus 11 cluster using the official docker and docker compose instruction. I scaled the cluster to 5 worker nodes and created a distributed table, with replication factor 3.
I expected the Citus cluster to work if I shutdown one worker…
PleaseLetMeGo
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