CQL - Practical Cassandra - page 39

DROP KEYSPACE
The DROP KEYSPACE command ( Listing 4.4 ) works exactly like the SQL DROP
DATABASE command. This operation is irreversible and removes all information
within the specified keyspace.
Listing 4.4 Example Usage of DROP KEYSPACE
DROP KEYSPACE Analytics;
CREATE TABLE/COLUMNFAMILY
The CREATE TABLE statement creates a table. A table is defined as a collection
of rows and columns. CREATE COLUMNFAMILY is an alias for CREATE
TABLE .
Primary Keys
The PRIMARY KEY in the table definition defines the physical key in the un-
derlying Cassandra data structure. Because of this, the PRIMARY KEY must be
defined in the column definitions. Other than this, the syntax is similar to the cor-
responding SQL syntax. When defining the PRIMARY KEY , if you decide to use
a compound key, only the first part of the key will be used as the underlying row
key. This is called the partition key. If you want to have a composite partition key,
this is defined by adding a set of parentheses around the parts you would like to
be the partition key. The remaining parts of the compound key will be used as the
physical parts of the composite columns in the underlying data structure. These are
called the clustering keys. The clustering keys will determine the order in which
the columns are stored on disk. You can optionally specify a clustering order that
will order the columns on disk and directly affect the ORDER BY clause. Listing
4.5 demonstrates creating a static table in CQL 3.
Listing 4.5 Example Usage of CREATE TABLE for a Static Table
Click here to view code image
CREATE TABLE users (
email text PRIMARY KEY,
first_name text,
last_name text,