UUID and TIMEUUID are stored the same way in Cassandra, and they only really represent two different sorting implementations. TIMEUUID columns are sorted by their time components first, and then by their raw bytes, whereas UUID columns are sorted by their version first, then if both are version 1 by their time component, and finally … Read more
Yes, you can use COUNT(*). Here’s the documentation. A SELECT expression using COUNT(*) returns the number of rows that matched the query. Alternatively, you can use COUNT(1) to get the same result. Count the number of rows in the users table: SELECT COUNT(*) FROM users;
Use the SOURCE http://www.datastax.com/documentation/cql/3.1/cql/cql_reference/source_r.html You can use -f option as well to execute commands from file http://www.datastax.com/documentation/cql/3.1/cql/cql_reference/cqlsh.html
You can use the timeuuid functions now() and dateof() (or in later versions of Cassandra, toTimestamp()), e.g., INSERT INTO TEST (ID, NAME, VALUE, LAST_MODIFIED_DATE) VALUES (‘2’, ‘elephant’, ‘SOME_VALUE’, dateof(now())); The now function takes no arguments and generates a new unique timeuuid (at the time where the statement using it is executed). The dateOf function takes … Read more
Short summary: Replication factor describes how many copies of your data exist. Consistency level describes the behavior seen by the client. Perhaps there’s a better way to categorize these. As an example, you can have a replication factor of 2. When you write, two copies will always be stored, assuming enough nodes are up. When … Read more
You need to edit cassandra.yaml on the node you are trying to connect to and set the node ip address for rpc_address and listen_address and restart Cassandra. rpc_address is the address on which Cassandra listens to the client calls. listen_address is the address on which Cassandra listens to the other Cassandra nodes.
Dbeaver in its free enterprise version (not open source) is good GUI client for Cassandra. No need of installation. Its portable. Also this client supports more than 20 databases. Community Edition of Dbeaver doesn’t have support for Cassandra, but we can use third party drivers for like Cdata to connect. Try the following GUI client … Read more
If you take a look at the Readme file at Apache Cassandra git repo, it says that, Cassandra is a partitioned row store. Rows are organized into tables with a required primary key. Partitioning means that Cassandra can distribute your data across multiple machines in an application-transparent matter. Cassandra will automatically repartition as machines are … Read more
To remove all rows from a CQL Table, you can use the TRUNCATE command: TRUNCATE keyspace_name.table_name; Or if you are already using the keyspace that contains your target table: TRUNCATE table_name; Important to note, but by default Cassandra creates a snapshot of the table just prior to TRUNCATE. Be sure to clean up old snapshots, … Read more
I’am not a cassandra expert, but did you tried nodetool stop compaction and to set a threshold for compaction (setcompactionthreshold to 0), so the system will not retry it