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Operator

Operand types

Description

A = B

All primitive types

TRUE if expression A is equal to expression B otherwise FALSE.

A <=> B

All primitive types

Returns same result with EQUAL(=) operator for non-null operands, but returns TRUE if both are NULL, FALSE if one of the them is NULL. (as As of version 0.9.0.)

A == B

None!

Fails because of invalid syntax. SQL uses =, not ==.

A <> B

All primitive types

NULL if A or B is NULL, TRUE if expression A is NOT equal to expression B, otherwise FALSE.

A != B

All primitive types

a synonym Synonym for the <> operator.

A < B

All primitive types

NULL if A or B is NULL, TRUE if expression A is less than expression B, otherwise FALSE.

A <= B

All primitive types

NULL if A or B is NULL, TRUE if expression A is less than or equal to expression B, otherwise FALSE.

A > B

All primitive types

NULL if A or B is NULL, TRUE if expression A is greater than expression B, otherwise FALSE.

A >= B

All primitive types

NULL if A or B is NULL, TRUE if expression A is greater than or equal to expression B, otherwise FALSE.

A [NOT] BETWEEN B AND C

All primitive types

NULL if A, B or C is NULL, TRUE if A is greater than or equal to B AND A less than or equal to C, otherwise FALSE. This can be inverted by using the NOT keyword. (as As of version 0.9.0.)

A IS NULL

all All types

TRUE if expression A evaluates to NULL, otherwise FALSE.

A IS NOT NULL

All types

FALSE if expression A evaluates to NULL, otherwise TRUE.

A [NOT] LIKE B

strings

NULL if A or B is NULL, TRUE if string A matches the SQL simple regular expression B, otherwise FALSE. The comparison is done character by character. The _ character in B matches any character in A (similar to . in posix regular expressions) while the % character in B matches an arbitrary number of characters in A (similar to .* in posix regular expressions) e. g. For example, 'foobar' like 'foo' evaluates to FALSE where as whereas 'foobar' like 'foo_ _ _' evaluates to TRUE and so does 'foobar' like 'foo%'.

A RLIKE B

strings

NULL if A or B is NULL, TRUE if any (possibly empty) substring of A matches the Java regular expression B, otherwise FALSE. E.g. For example, 'foobar' RLIKE 'foo' evaluates to TRUE and so does 'foobar' RLIKE '^f.*r$'.

A REGEXP B

strings

Same as RLIKE.

Arithmetic Operators

The following operators support various common arithmetic operations on the operands. All return number types; if any of the operands are NULL, then the result is also NULL.

Operator

Operand types

Description

A + B

All number types

Gives the result of adding A and B. The type of the result is the same as the common parent(in the type hierarchy) of the types of the operands. e.g. For example since every integer is a float, therefore float is a containing type of integer so the + operator on a float and an int will result in a float.

A - B

All number types

Gives the result of subtracting B from A. The type of the result is the same as the common parent(in the type hierarchy) of the types of the operands.

A * B

All number types

Gives the result of multiplying A and B. The type of the result is the same as the common parent(in the type hierarchy) of the types of the operands. Note that if the multiplication causing overflow, you will have to cast one of the operators to a type higher in the type hierarchy.

A / B

All number types

Gives the result of dividing B from A. The result is a double type.

A % B

All number types

Gives the reminder resulting from dividing A by B. The type of the result is the same as the common parent(in the type hierarchy) of the types of the operands.

A & B

All number types

Gives the result of bitwise AND of A and B. The type of the result is the same as the common parent(in the type hierarchy) of the types of the operands.

A | B

All number types

Gives the result of bitwise OR of A and B. The type of the result is the same as the common parent(in the type hierarchy) of the types of the operands.

A ^ B

All number types

Gives the result of bitwise XOR of A and B. The type of the result is the same as the common parent(in the type hierarchy) of the types of the operands.

~A

All number types

Gives the result of bitwise NOT of A. The type of the result is the same as the type of A.

...

Operator

Operand types

Description

A AND B

boolean

TRUE if both A and B are TRUE, otherwise FALSE. NULL if A or B is NULL.

A && B

boolean

Same as A AND B.

A OR B

boolean

TRUE if either A or B or both are TRUE; , FALSE OR NULL is NULL; , otherwise FALSE.

A || B

boolean

Same as A OR B.

NOT A

boolean

TRUE if A is FALSE or NULL if A is NULL. Otherwise FALSE.

! A

boolean

Same as NOT A.

A IN (val1, val2, ...)

boolean

TRUE if A is equal to any of the values. As of Hive 0.13 subqueries are supported in IN statements.

A NOT IN (val1, val2, ...)

boolean

TRUE if A is not equal to any of the values. As of Hive 0.13 subqueries are supported in NOT IN statements.

[NOT] EXISTS (subquery)

 

TRUE if the the subquery returns at least one row. Supported as of Hive 0.13.

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Constructor Function

Operands

Description

map

(key1, value1, key2, value2, ...)

Creates a map with the given key/value pairs.

struct

(val1, val2, val3, ...)

Creates a struct with the given field values. Struct field names will be col1, col2, ....

named_struct

(name1, val1, name2, val2, ...)

Creates a struct with the given field names and values. (as As of Hive 0.8.0.)

array

(val1, val2, ...)

Creates an array with the given elements.

create_union

(tag, val1, val2, ...)

Creates a union type with the value that is being pointed to by the tag parameter.

Operators on Complex Types

...

Operator

Operand types

Description

A[n]

A is an Array and n is an int

Returns the nth element in the array A. The first element has index 0 e. g. For example, if A is an array comprising of ['foo', 'bar'] then A[0] returns 'foo' and A[1] returns 'bar'.

M[key]

M is a Map<K, V> and key has type K

Returns the value corresponding to the key in the map e. g. For example, if M is a map comprising of {'f' -> 'foo', 'b' -> 'bar', 'all' -> 'foobar'} then M['all'] returns 'foobar'.

S.x

S is a struct

Returns the x field of S. e.g For example for the struct foobar {int foo, int bar}, foobar.foo returns the integer stored in the foo field of the struct.

...

Return Type

Name (Signature)

Description

DOUBLE

round(DOUBLE a)

Returns the rounded BIGINT value of a.

DOUBLE

round(DOUBLE a, INT d)

Returns a rounded to d decimal places.

BIGINT

floor(DOUBLE a)

Returns the maximum BIGINT value that is equal to or less than a.

BIGINT

ceil(DOUBLE a), ceiling(DOUBLE a)

Returns the minimum BIGINT value that is equal to or greater than a.

DOUBLE

rand(), rand(INT seed)

Returns a random number (that changes from row to row) that is distributed uniformly from 0 to 1. Specifying the seed will make sure the generated random number sequence is deterministic.

DOUBLE

exp(DOUBLE a), exp(DECIMAL a)

Returns ea where e is the base of the natural logarithm. Decimal version added in Hive 0.13.0.

DOUBLE

ln(DOUBLE a), ln(DECIMAL a)

Returns the natural logarithm of the argument a. Decimal version added in Hive 0.13.0.

DOUBLE

log10(DOUBLE a), log10(DECIMAL a)

Returns the base-10 logarithm of the argument a. Decimal version added in Hive 0.13.0.

DOUBLE

log2(DOUBLE a), log2(DECIMAL a)

Returns the base-2 logarithm of the argument a. Decimal version added in Hive 0.13.0.

DOUBLE

log(DOUBLE base, DOUBLE a)

log(DECIMAL base, DECIMAL a)

Return Returns the base-base logarithm of the argument d a. Decimal versions added in Hive 0.13.0.

DOUBLE

pow(DOUBLE a, DOUBLE p), power(DOUBLE a, DOUBLE p)

Return Returns ap.

DOUBLE

sqrt(DOUBLE a), sqrt(DECIMAL a)

Returns the square root of a. Decimal version added in Hive 0.13.0.

STRING

bin(BIGINT a)

Returns the number in binary format (see http://dev.mysql.com/doc/refman/5.0/en/string-functions.html#function_bin).

STRING

hex(BIGINT a) hex(STRING a) hex(BINARY a)

If the argument is an INT or binary, hex returns the number as a STRING in hex hexadecimal format. Otherwise if the number is a STRING, it converts each character into its hex hexadecimal representation and returns the resulting STRING. (see See http://dev.mysql.com/doc/refman/5.0/en/string-functions.html#function_hex, BINARY version as of Hive 0.12.0.)

BINARY

unhex(STRING a)

Inverse of hex. Interprets each pair of characters as a hexadecimal number and converts to the byte representation of the number. (BINARY version as of Hive 0.12.0, used to return a string.)

STRING

conv(BIGINT num, INT from_base, INT to_base), conv(STRING num, INT from_base, INT to_base)

Converts a number from a given base to another (see http://dev.mysql.com/doc/refman/5.0/en/mathematical-functions.html#function_conv).

DOUBLE

abs(DOUBLE a)

Returns the absolute value.

INT or DOUBLE

pmod(INT a, INT b), pmod(DOUBLE a, DOUBLE b)

Returns the positive value of a mod b.

DOUBLE

sin(DOUBLE a), sin(DECIMAL a)

Returns the sine of a (a is in radians). Decimal version added in Hive 0.13.0.

DOUBLE

asin(DOUBLE a), asin(DECIMAL a)

Returns the arc sin of a if -1<=a<=1 or NULL otherwise. Decimal version added in Hive 0.13.0.

DOUBLE

cos(DOUBLE a), cos(DECIMAL a)

Returns the cosine of a (a is in radians). Decimal version added in Hive 0.13.0.

DOUBLE

acos(DOUBLE a), acos(DECIMAL a)

Returns the arccosine of a if -1<=a<=1 or NULL otherwise. Decimal version added in Hive 0.13.0.

DOUBLE

tan(DOUBLE a), tan(DECIMAL a)

Returns the tangent of a (a is in radians). Decimal version added in Hive 0.13.0.

DOUBLE

atan(DOUBLE a), atan(DECIMAL a)

Returns the arctangent of a. Decimal version added in Hive 0.13.0.

DOUBLE

degrees(DOUBLE a), degrees(DECIMAL a)

Converts value of a from radians to degrees. Decimal version added in Hive 0.13.0.

DOUBLE

radians(DOUBLE a), radians(DOUBLE a)

Converts value of a from degrees to radians. Decimal version added in Hive 0.13.0.

INT or DOUBLE

positive(INT a), positive(DOUBLE a)

Returns a.

INT or DOUBLE

negative(INT a), negative(DOUBLE a)

Returns -a.

DOUBLE or INT

sign(DOUBLE a), sign(DECIMAL a)

Returns the sign of a as '1.0' (if a is positive) or '-1.0' (if a is negative), '0.0' otherwise. The decimal version returns INT instead of DOUBLE. Decimal version added in Hive 0.13.0.

DOUBLE

e()

Returns the value of e.

DOUBLE

pi()

Returns the value of pi.

Mathematical Functions and Operators for Decimal Datatypes

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Return Type

Name(Signature)

Description

int

size(Map<K.V>)

Returns the number of elements in the map type.

int

size(Array<T>)

Returns the number of elements in the array type.

array<K>

map_keys(Map<K.V>)

Returns an unordered array containing the keys of the input map.

array<V>

map_values(Map<K.V>)

Returns an unordered array containing the values of the input map.

boolean

array_contains(Array<T>, value)

Returns TRUE if the array contains value.

array<t>

sort_array(Array<T>)

Sorts the input array in ascending order according to the natural ordering of the array elements and returns it (as of version 0.9.0).

Type Conversion Functions

...

Return Type

Name(Signature)

Description

binary

binary(string|binary)

Casts the parameter into a binary.

Expected "=" to follow "type"

cast(expr as <type>)

Converts the results of the expression expr to <type> e. g. For example, cast('1' as BIGINT) will convert the string '1' to it its integral representation. A null is returned if the conversion does not succeed.

...

Return Type

Name(Signature)

Description

string

from_unixtime(bigint unixtime[, string format])

Converts the number of seconds from unix epoch (1970-01-01 00:00:00 UTC) to a string representing the timestamp of that moment in the current system time zone in the format of "1970-01-01 00:00:00".

bigint

unix_timestamp()

Gets current Unix timestamp in seconds.

bigint

unix_timestamp(string date)

Converts time string in format yyyy-MM-dd HH:mm:ss to Unix timestamp (in seconds), using the default timezone and the default locale, return 0 if fail: unix_timestamp('2009-03-20 11:30:01') = 1237573801

bigint

unix_timestamp(string date, string pattern)

Convert time string with given pattern (see [http://java.sun.com/j2se/1.4.2/docs/api/java/text/SimpleDateFormat.html]) to Unix time stamp (in seconds), return 0 if fail: unix_timestamp('2009-03-20', 'yyyy-MM-dd') = 1237532400.

string

to_date(string timestamp)

Returns the date part of a timestamp string: to_date("1970-01-01 00:00:00") = "1970-01-01".

int

year(string date)

Returns the year part of a date or a timestamp string: year("1970-01-01 00:00:00") = 1970, year("1970-01-01") = 1970.

int

month(string date)

Returns the month part of a date or a timestamp string: month("1970-11-01 00:00:00") = 11, month("1970-11-01") = 11.

int

day(string date) dayofmonth(date)

Return Returns the day part of a date or a timestamp string: day("1970-11-01 00:00:00") = 1, day("1970-11-01") = 1.

int

hour(string date)

Returns the hour of the timestamp: hour('2009-07-30 12:58:59') = 12, hour('12:58:59') = 12.

int

minute(string date)

Returns the minute of the timestamp.

int

second(string date)

Returns the second of the timestamp.

int

weekofyear(string date)

Return Returns the week number of a timestamp string: weekofyear("1970-11-01 00:00:00") = 44, weekofyear("1970-11-01") = 44.

int

datediff(string enddate, string startdate)

Return Returns the number of days from startdate to enddate: datediff('2009-03-01', '2009-02-27') = 2.

string

date_add(string startdate, int days)

Add Adds a number of days to startdate: date_add('2008-12-31', 1) = '2009-01-01'.

string

date_sub(string startdate, int days)

Subtract Subtracts a number of days to startdate: date_sub('2008-12-31', 1) = '2008-12-30'.

timestamp

from_utc_timestamp(timestamp, string timezone)

Assumes given timestamp is UTC and converts to given timezone (as of Hive 0.8.0).

timestamp

to_utc_timestamp(timestamp, string timezone)

Assumes given timestamp is in given timezone and converts to UTC (as of Hive 0.8.0).

Conditional Functions

Return Type

Name(Signature)

Description

T

if(boolean testCondition, T valueTrue, T valueFalseOrNull)

Return Returns valueTrue when testCondition is true, returns valueFalseOrNull otherwise.

T

COALESCE(T v1, T v2, ...)

Return Returns the first v that is not NULL, or NULL if all v's are NULL.

T

CASE a WHEN b THEN c [WHEN d THEN e]* [ELSE f] END

When a = b, returns c; when a = d, return returns e; else return returns f.

T

CASE WHEN a THEN b [WHEN c THEN d]* [ELSE e] END

When a = true, returns b; when c = true, return returns d; else return returns e.

String Functions

The following built-in String functions are supported in hive:

Return Type

Name(Signature)

Description

int

ascii(string str)

Returns the numeric value of the first character of str.

string

base64(binary bin)

Convert Converts the argument from binary to a base 64 string (as of Hive 0.12.0).

string

concat(string|binary A, string|binary B...)

Returns the string or bytes resulting from concatenating the strings or bytes passed in as parameters in order. e.g. For example, concat('foo', 'bar') results in 'foobar'. Note that this function can take any number of input strings.

array<struct<string,double>>

context_ngrams(array<array<string>>, array<string>, int K, int pf)

Returns the top-k contextual N-grams from a set of tokenized sentences, given a string of "context". See StatisticsAndDataMining for more information.

string

concat_ws(string SEP, string A, string B...)

Like concat() above, but with custom separator SEP.

string

concat_ws(string SEP, array<string>)

Like concat_ws() above, but taking an array of strings. (as of Hive 0.9.0)

string

decode(binary bin, string charset)

Decode Decodes the first argument into a String using the provided character set (one of 'US_ASCII', 'ISO-8859-1', 'UTF-8', 'UTF-16BE', 'UTF-16LE', 'UTF-16'). If either argument is null, the result will also be null. (as As of Hive 0.12.0.)

binary

encode(string src, string charset)

Encode Encodes the first argument into a BINARY using the provided character set (one of 'US_ASCII', 'ISO-8859-1', 'UTF-8', 'UTF-16BE', 'UTF-16LE', 'UTF-16'). If either argument is null, the result will also be null. (as As of Hive 0.12.0.)

int

find_in_set(string str, string strList)

Returns the first occurance of str in strList where strList is a comma-delimited string. Returns null if either argument is null. Returns 0 if the first argument contains any commas. e.g. For example, find_in_set('ab', 'abc,b,ab,c,def') returns 3.

string

format_number(number x, int d)

Formats the number X to a format like '#,###,###.##', rounded to D decimal places, and returns the result as a string. If D is 0, the result has no decimal point or fractional part. (as As of Hive 0.10.0; bug with float types fixed in Hive 0.14.0.)

string

get_json_object(string json_string, string path)

Extract Extracts json object from a json string based on json path specified, and return returns json string of the extracted json object. It will return null if the input json string is invalid. NOTE: The json path can only have the characters [0-9a-z_], i.e., no upper-case or special characters. Also, the keys *cannot start with numbers.* This is due to restrictions on Hive column names.

boolean

in_file(string str, string filename)

Returns true if the string str appears as an entire line in filename.

int

instr(string str, string substr)

Returns the position of the first occurrence of substr in str. Returns null if either of the arguments are null and returns 0 if substr could not be found in str. Be aware that this is not zero based. The first character in str has index 1.

int

length(string A)

Returns the length of the string.

int

locate(string substr, string str[, int pos])

Returns the position of the first occurrence of substr in str after position pos.

string

lower(string A) lcase(string A)

Returns the string resulting from converting all characters of B to lower case e. g. For example, lower('fOoBaR') results in 'foobar'.

string

lpad(string str, int len, string pad)

Returns str, left-padded with pad to a length of len.

string

ltrim(string A)

Returns the string resulting from trimming spaces from the beginning(left hand side) of A e. g. For example, ltrim(' foobar ') results in 'foobar '.

array<struct<string,double>>

ngrams(array<array<string>>, int N, int K, int pf)

Returns the top-k N-grams from a set of tokenized sentences, such as those returned by the sentences() UDAF. See StatisticsAndDataMining for more information.

string

parse_url(string urlString, string partToExtract [, string keyToExtract])

Returns the specified part from the URL. Valid values for partToExtract include HOST, PATH, QUERY, REF, PROTOCOL, AUTHORITY, FILE, and USERINFO. e.g. For example, parse_url('http://facebook.com/path1/p.php?k1=v1&k2=v2#Ref1', 'HOST') returns 'facebook.com'. Also a value of a particular key in QUERY can be extracted by providing the key as the third argument, e.g. for example, parse_url('http://facebook.com/path1/p.php?k1=v1&k2=v2#Ref1', 'QUERY', 'k1') returns 'v1'.

string

printf(String format, Obj... args)

Returns the input formatted according do printf-style format strings (as of Hive 0.9.0).

string

regexp_extract(string subject, string pattern, int index)

Returns the string extracted using the pattern. e.g. For example, regexp_extract('foothebar', 'foo(.*?)(bar)', 2) returns 'bar.' Note that some care is necessary in using predefined character classes: using '\s' as the second argument will match the letter s; '
s' is necessary to match whitespace, etc. The 'index' parameter is the Java regex Matcher group() method index. See docs/api/java/util/regex/Matcher.html for more information on the 'index' or Java regex group() method.

string

regexp_replace(string INITIAL_STRING, string PATTERN, string REPLACEMENT)

Returns the string resulting from replacing all substrings in INITIAL_STRING that match the java regular expression syntax defined in PATTERN with instances of REPLACEMENT, e.g. . For example, regexp_replace("foobar", "oo|ar", "") returns 'fb.' Note that some care is necessary in using predefined character classes: using '\s' as the second argument will match the letter s; '
s' is necessary to match whitespace, etc.

string

repeat(string str, int n)

Repeat Repeats str n times.

string

reverse(string A)

Returns the reversed string.

string

rpad(string str, int len, string pad)

Returns str, right-padded with pad to a length of len.

string

rtrim(string A)

Returns the string resulting from trimming spaces from the end(right hand side) of A e. g. For example, rtrim(' foobar ') results in ' foobar'.

array<array<string>>

sentences(string str, string lang, string locale)

Tokenizes a string of natural language text into words and sentences, where each sentence is broken at the appropriate sentence boundary and returned as an array of words. The 'lang' and 'locale' are optional arguments. e.g. For example, sentences('Hello there! How are you?') returns ( ("Hello", "there"), ("How", "are", "you") ).

string

space(int n)

Return Returns a string of n spaces.

array

split(string str, string pat)

Split Splits str around pat (pat is a regular expression).

map<string,string>

str_to_map(text[, delimiter1, delimiter2])

Splits text into key-value pairs using two delimiters. Delimiter1 separates text into K-V pairs, and Delimiter2 splits each K-V pair. Default delimiters are ',' for delimiter1 and '=' for delimiter2.

string

substr(string|binary A, int start) substring(string|binary A, int start)

Returns the substring or slice of the byte array of A starting from start position till the end of string A e. g. For example, substr('foobar', 4) results in 'bar' (see [http://dev.mysql.com/doc/refman/5.0/en/string-functions.html#function_substr]).

string

substr(string|binary A, int start, int len) substring(string|binary A, int start, int len)

Returns the substring or slice of the byte array of A starting from start position with length len e. g. For example, substr('foobar', 4, 1) results in 'b' (see [http://dev.mysql.com/doc/refman/5.0/en/string-functions.html#function_substr]).

string

translate(string input, string from, string to)

Translates the input string by replacing the characters present in the from string with the corresponding characters in the to string. This is similar to the translate function in PostgreSQL. If any of the parameters to this UDF are NULL, the result is NULL as well. (available Available as of Hive 0.10.0.)

string

trim(string A)

Returns the string resulting from trimming spaces from both ends of A e. g. For example, trim(' foobar ') results in 'foobar'

binary

unbase64(string str)

Convert Converts the argument from a base 64 string to BINARY. (as As of Hive 0.12.0.)

string

upper(string A) ucase(string A)

Returns the string resulting from converting all characters of A to upper case e. g. For example, upper('fOoBaR') results in 'FOOBAR'.

Misc. Functions

Return Type

Name(Signature)

Description

varies

java_method(class, method[, arg1[, arg2..]])

Synonym for reflect. (as As of Hive 0.9.0.)

varies

reflect(class, method[, arg1[, arg2..]])

Use this UDF to call Java methods Calls a Java method by matching the argument signature (uses , using reflection). (As of Hive 0.7.0.) See Reflect (Generic) UDF for examples.

int

hash(a1[, a2...])

Returns a hash value of the arguments. (as As of Hive 0.4.)

xpath

The following functions are described in LanguageManual XPathUDF:

...

Return Type

Name(Signature)

Description

BIGINT

count(*), count(expr), count(DISTINCT expr[, expr_.])

count(*) - Returns the total number of retrieved rows, including rows containing NULL values; count(expr) - Returns the number of rows for which the supplied expression is non-NULL; count(DISTINCT expr[, expr]) - Returns the number of rows for which the supplied expression(s) are unique and non-NULL.

DOUBLE

sum(col), sum(DISTINCT col)

Returns the sum of the elements in the group or the sum of the distinct values of the column in the group.

DOUBLE

avg(col), avg(DISTINCT col)

Returns the average of the elements in the group or the average of the distinct values of the column in the group.

DOUBLE

min(col)

Returns the minimum of the column in the group.

DOUBLE

max(col)

Returns the maximum value of the column in the group.

DOUBLE

variance(col), var_pop(col)

Returns the variance of a numeric column in the group.

DOUBLE

var_samp(col)

Returns the unbiased sample variance of a numeric column in the group.

DOUBLE

stddev_pop(col)

Returns the standard deviation of a numeric column in the group.

DOUBLE

stddev_samp(col)

Returns the unbiased sample standard deviation of a numeric column in the group.

DOUBLE

covar_pop(col1, col2)

Returns the population covariance of a pair of numeric columns in the group.

DOUBLE

covar_samp(col1, col2)

Returns the sample covariance of a pair of a numeric columns in the group.

DOUBLE

corr(col1, col2)

Returns the Pearson coefficient of correlation of a pair of a numeric columns in the group.

DOUBLE

percentile(BIGINT col, p)

Returns the exact pth percentile of a column in the group (does not work with floating point types). p must be between 0 and 1. NOTE: A true percentile can only be computed for integer values. Use PERCENTILE_APPROX if your input is non-integral.

array<double>

percentile(BIGINT col, array(p1 [, p2]...))

Returns the exact percentiles p1, p2, ... of a column in the group (does not work with floating point types). pi must be between 0 and 1. NOTE: A true percentile can only be computed for integer values. Use PERCENTILE_APPROX if your input is non-integral.

DOUBLE

percentile_approx(DOUBLE col, p [, B])

Returns an approximate pth percentile of a numeric column (including floating point types) in the group. The B parameter controls approximation accuracy at the cost of memory. Higher values yield better approximations, and the default is 10,000. When the number of distinct values in col is smaller than B, this gives an exact percentile value.

array<double>

percentile_approx(DOUBLE col, array(p1 [, p2]...) [, B])

Same as above, but accepts and returns an array of percentile values instead of a single one.

array<struct {'x','y'}>

histogram_numeric(col, b)

Computes a histogram of a numeric column in the group using b non-uniformly spaced bins. The output is an array of size b of double-valued (x,y) coordinates that represent the bin centers and heights

array

collect_set(col)

Returns a set of objects with duplicate elements eliminated.

array

collect_list(col)

Returns a list of objects with duplicates. (as As of Hive 0.13.0.)

INTEGERntile(INTEGER x)

This function divides Divides an ordered partition into x groups called buckets and assigns a bucket number to each row in the partition. This allows easy calculation of tertiles, quartiles, deciles, percentiles and other common summary statistics. (As of Hive 0.11.0.)

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Return Type

Name(Signature)

Description

N rows

explode(ARRAY)

Returns one row for each element from the array.

N rows

explode(MAP)

Returns one row for each key-value pair from the input map with two columns in each row: one for the key and another for the value. (as As of Hive 0.8.0.)

 

inline(ARRAY<STRUCT[,STRUCT]>)

Explodes an array of structs into a table. (as As of Hive 0.10.)

Array Type

explode(array<TYPE> a)

For each element in a, explode() generates a row containing that element.

tuple

json_tuple(jsonStr, k1, k2, ...)

It takes Takes a set of names (keys) and a JSON string, and returns a tuple of values. This is a more efficient version of the get_json_object UDF because it can get multiple keys with just one call.

tuple

parse_url_tuple(url, p1, p2, ...)

This is similar to the parse_url() UDF but can extract multiple parts at once out of a URL. Valid part names are: HOST, PATH, QUERY, REF, PROTOCOL, AUTHORITY, FILE, USERINFO, QUERY:<KEY>.

N rows

posexplode(ARRAY)

Behaves like explode for arrays, but includes the position of items in the original array by returning a tuple of (pos, value). (as As of Hive 0.13.0.)

 

stack(INT n, v_1, v_2, ..., v_k)

Breaks up v_1, ..., v_k into n rows. Each row will have k/n columns. n must be constant.

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The parse_url_tuple() UDTF is similar to parse_url(), but can extract multiple parts of a given URL, returning the data in a tuple. Values for a particular key in QUERY can be extracted by appending a colon and the key to the partToExtract argument, e.g. parse, for example, parse_url_tuple('http://facebook.com/path1/p.php?k1=v1&k2=v2#Ref1', 'QUERY:k1', 'QUERY:k2') returns a tuple with values of 'v1','v2'. This is more efficient than calling parse_url() multiple times. All the input parameters and output column types are string.

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would evaluate the length of each of the string_col's values in the map portion of the job. The side effect of the UDF being evaluated on the map-side is that you can't control the order of rows which get sent to the mapper. It is the same order in which the file split sent to the mapper gets deserialized. Any reduce side operation (e.g. SORT such as SORT BY, ORDER BY, regular JOIN, etc.) would apply to the UDFs output as if it is just another column of the table. This is fine since the context of the UDF's evaluate method is meant to be one row at a time.

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