Database Reference
In-Depth Information
Category
Expressions
Description
Examples
Boolean
Logical
OR
x
OR
y
q == 0 OR q == 1
Logical
AND
x
AND
y
q == 0 AND r == 0
Logical negation
NOT
x
NOT q matches
'[01459]'
Set membership
IN
x
q IN (0, 1, 4, 5, 9)
Functional
fn
(
f1
,
f2
,...)
Invocation of function
fn
on fields
f1
,
f2
, etc.
isGood(quality)
Flatten
Removal of a level of nesting from
bags and tuples
FLATTEN(
f
)
FLATTEN(group)
Types
So far you have seen some of the simple types in Pig, such as
int
and
chararray
.
Here we will discuss Pig's built-in types in more detail.
Pig has a
boolean
type and six numeric types:
int
,
long
,
float
,
double
,
bigin-
teger
, and
bigdecimal
, which are identical to their Java counterparts. There is also a
bytearray
type, like Java's
byte
array type for representing a blob of binary data, and
chararray
, which, like
java.lang.String
, represents textual data in UTF-16
format (although it can be loaded or stored in UTF-8 format). The
datetime
type is for
storing a date and time with millisecond precision and including a time zone.
Pig does not have types corresponding to Java's
byte
,
short
, or
char
primitive types.
These are all easily represented using Pig's
int
type, or
chararray
for
char
.
The Boolean, numeric, textual, binary, and temporal types are simple atomic types. Pig
Latin also has three complex types for representing nested structures:
tuple
,
bag
, and
map
. All of Pig Latin's types are listed in
Table 16-6
.
