CODEWITHSUNDEEP
cassandra
Ike Walker
Ike Walker

Reputation: 65547

How do I delete all data in a Cassandra column family?

I'm looking for a way to delete all of the rows from a given column family in cassandra.

This is the equivalent of TRUNCATE TABLE in SQL.

Upvotes: 54

Views: 65013

Answers (6)

the paul
the paul

Reputation: 9161

You can use the truncate thrift call, or the TRUNCATE <table> command in CQL.

http://www.datastax.com/docs/1.0/references/cql/TRUNCATE

Upvotes: 84

Swam Guru
Swam Guru

Reputation: 473

if you are working on cluster setup, truncate can only be used when all the nodes of the cluster are UP.

By using truncate, we will miss the data(we are not sure with the importance of the data)

So the very safe way as well a trick to delete data is to use COPY command,

1) backup data using copy cassandra cmd
copy tablename to 'path'

2) duplicate the file using linux cp cmd
cp 'src path' 'dst path'

3) edit duplicate file in dst path, delete all lines expect first line.
save the file.

4) use copy cassandra cmd to import
copy tablename from 'dst path'

Upvotes: 0

Sumod
Sumod

Reputation: 3846

If you are using cqlsh, then you can either do it in 2 ways

  1. use keyspace; and then truncate column_family;
  2. truncate keyspace.column_family;

If you want to use DataStax Java driver, you can look at - http://www.datastax.com/drivers/java/1.0/com/datastax/driver/core/querybuilder/QueryBuilder.html or http://www.datastax.com/drivers/java/2.0/com/datastax/driver/core/querybuilder/Truncate.html

depending on your version.

Upvotes: 3

cevaris
cevaris

Reputation: 5794

You can also do this via Cassandra CQL.

$ cqlsh
Connected to Test Cluster at localhost:9160.
[cqlsh 4.1.1 | Cassandra 2.0.6 | CQL spec 3.1.1 | Thrift protocol 19.39.0]
Use HELP for help.
cqlsh> TRUNCATE my_keyspace.my_column_family;

Upvotes: 9

Eugen
Eugen

Reputation: 2370

If you are using Hector it is easy as well:

cluster.truncate("our keyspace name here", "your column family name here");

Upvotes: 3

abhi
abhi

Reputation: 4792

Its very simple in Astyanax. Just a Single Line statement

/* keyspace variable is Keyspace Type */
keyspace.truncateColumnFamily(ColumnFamilyName);

Upvotes: 6

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