2)Hive data storage,data types and functions:

Hive data storage,data types and functions:

Hive data storage:

Hive data is organized into:

1. Databases:Metastore of table
2. Tables: resides on HDFS
   
3. Partitions: Each Table can have one or more partition Keys which determines how the data is stored.
4. Buckets (or Clusters):Data in each partition may in turn be divided into Buckets based on the value of a hash function of some column of the Table.

Hive Data Types:

Hive supports primitive and complex data types,

1)Primitive Types:

• Integers

    TINYINT—1 byte integer
    SMALLINT—2 byte integer
    INT—4 byte integer
    BIGINT—8 byte integer

• Boolean type

    BOOLEAN—TRUE/FALSE

• Floating point numbers

    FLOAT—single precision
    DOUBLE—Double precision

• Fixed point numbers

    DECIMAL—a fixed point value of user defined scale and precision

• String types

• STRING—sequence of characters in a specified character set
• VARCHAR—sequence of characters in a specified character set with a maximum length
• CHAR—sequence of characters in a specified character set with a defined length

• Date and time types

    TIMESTAMP— a specific point in time, up to nanosecond precision
    DATE—a date

• Binary types

    BINARY—a sequence of bytes

2)Complex Types:

arrays: ARRAY<data_type>
maps: MAP<primitive_type, data_type>
structs: STRUCT<col_name : data_type [COMMENT col_comment], ...>
union: UNIONTYPE<data_type, data_type, ...>

Hive Built In Operators and Functions: 

In Hive CLI, use these commands to see the latest documentation:

SHOW FUNCTIONS;
DESCRIBE FUNCTION <function_name>;
DESCRIBE FUNCTION EXTENDED <function_name>;

 *SHOW FUCNTIONS:

*DESCRIBE FUNCTION <name_of_fuction>:

*DESCRIBE FUNCTION EXTENDED <name_of_function>;

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