In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "Copy hdfs-site.xml and core-site.xml from Hadoop cluster to each Impala node into the Impala configuration folder, /etc/impala/conf."

Keywords in the text are shown as follows: "Impala statements support data manipulation statements similar to DML (Data Manipulation Language)."

Impala shell commands or Impala SQL statements are written as follows:

CREATE TABLE table_name (def data_type) 
PARTITIONED BY (partiton_name partition_type);
ALTER TABLE table_name ADD PARTITION (partition_type='definition'),

When an Impala command or Impala SQL statement is used to show an example, either console output or query output is also displayed for complete understanding. In this scenario, either command or query is shown in bold as follows:

[Hadoop.testdomain:21000] > select count(distinct(make)) from automobiles;
Query finished, fetching results ...
+----------------------+
| count(distinct make) |
+----------------------+
| 10                   |
+----------------------+
Returned 1 row(s) in 0.48s 

Another example is as follows:

[cloudera@localhost ~]$ hdfs dfs -ls /user/cloudera/automobiles/
Found 1 items
-rw-r--r--   3 cloudera cloudera        985 2013-10-15 19:17 /user/cloudera/automobiles/automobiles.txt