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How do I know what 'keyspace' the node currently hosts? |
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Subject: How do I know what 'keyspace' the node currently hosts?
Author: EricJ
In response to: CQL by Example
Posted on: 09/30/2015 01:53:03 AM
cqlsh> select * from system.schema_keyspaces;
keyspace_name | durable_writes | strategy_class | strategy_options
--------------------+----------------+---------------------------------------------
system_auth | True | SimpleStrategy | {"replication_factor":"1"}
playlist | True | SimpleStrategy | {"replication_factor":"1"}
system_distributed | True | SimpleStrategy | {"replication_factor":"3"}
system | True | LocalStrategy | {}
system_traces | True | SimpleStrategy | {"replication_factor":"2"}
(5 rows)
Here, the keyspace 'playlist' is created by user, others are system's.
>
> On 09/30/2015 01:50:04 AM EricJ wrote:
Step 1. Create a new keyspace called 'playlist'
cqlsh> create KEYSPACE playlist WITH replication
= {'class':'SimpleStrategy', 'replication_factor': 1 };
Step 2. Use a keyspace
Step 3. Create column families or tables
cqlsh:playlist> create table artists_by_first_letter (
first_letter text,
artist text,
primary key (first_letter, artist));
cqlsh:playlist> create table track_by_artist (
track text,
artist text,
track_id UUID,
track_length_in_seconds int,
genre text,music_file text,
primary key (artist, track, track_id));
cqlsh:playlist> create table track_by_genre (
track text, artist text,
track_id UUID,
track_length_in_seconds int,
genre text,
music_file text,
primary key (genre, artist, track, track_id));
Step 4. Populate the tables with data from files
cqlsh:playlist> copy artists_by_first_letter (first_letter, artist)
FROM 'scripts/artists.csv' WITH DELIMITER = '|';
cqlsh:playlist> copy track_by_artist (track_id, genre, artist, track,
track_length_in_seconds, music_file)
FROM 'scripts/songs.csv'
WITH DELIMITER = '|' AND HEADER=true;
cqlsh:playlist> copy track_by_genre (track_id, genre, artist, track,
track_length_in_seconds, music_file)
FROM 'scripts/songs.csv'
WITH DELIMITER = '|' AND HEADER=true;
Step 5. Export the tables to file
cqlsh:playlist> copy artists_by_first_letter (first_letter, artist)
TO 'scripts/artists_out.csv'
WITH DELIMITER = '|' AND HEADER=true;
Step 6. Check table content
cqlsh:playlist> select * from artists_by_first_letter;
Step 7. Quit cqlsh
References:
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