THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
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Normal user-defined functions, such as concat(), take in a single input row and output a single output row. In contrast, table-generating functions transform a single input row into multiple output rows. UDTF is one of the most advanced functions.
Row-set columns types | Name(Signature) | Description | OSS |
|---|---|---|---|
T | explode(ARRAY<T> a) | Explodes an array to multiple rows. Returns a row-set with a single column (col), one row for each element from the array. | |
Tkey,Tvalue | explode(MAP<Tkey,Tvalue> m) | Explodes a map to multiple rows. Returns a row-set with two columns (key,value) , one row for each key-value pair from the input map. | |
| int,T | posexplode(ARRAY<T> a) | Explodes an array to multiple rows with an additional positional column ofint type (position of items in the original array, starting with 0). Returns a row-set with two columns (pos,val), one row for each element from the array. | GenericUDTFPosExplode |
T1,...,Tn | inline(ARRAY<STRUCT<f1:T1,...,fn:Tn>> a) | Explodes an array of structs to multiple rows. Returns a row-set with N columns (N = number of top level elements in the struct), one row per struct from the array. | |
| T1,...,Tn/r | stack(int r,T1 V1,...,Tn/r Vn) | Breaks up n values V1,...,Vninto r rows. Each row will have n/r columns. r must be constant. | GenericUDTFStack |
| string1,...,stringn | json_tuple(string jsonStr, string k1,...,string kn) | Takes JSON string and a set of n keys, and returns a tuple of n values. This is a more efficient version of the get_json_object UDF because it can get multiple keys with just one call. | GenericUDTFJSONTuple |
string 1,...,stringn | parse_url_tuple(string urlStr, string p1,...,string pn) | Takes URLstring and a set of n URL parts, and returns a tuple of n values. 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>. |
String Functions
There is no good engine without string manipulation functions. Apache Hive has rich built-instring functions.
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