UUID()

Returns a Universal Unique Identifier (UUID).

UUID Example
SELECT uuid() AS uuid FROM stream
=> 64c82e4c-7314-45e2-8ee2-c7283f6dbb74

Hash(Object o)

Returns the hash value of an object

Hash Example
SELECT hash(value) AS hash FROM stream
=> 1402455053

Eval(String s)

Evaluates arbitrary expressions.

Eval Example
SELECT eval("2+3") as result FROM stream
=> 5

Sleep(Number time)

Causes the currently executing operator to sleep for the specified number of milliseconds.

eIf(Expression e, Object true, Object false)

Returns the first Object if the expression evaluates to true else the second Object.

eIf Example
SELECT eif(1>0, "Greater than 0", "Lower or equal") AS result FROM stream
=> Greater than 0

The functions can be nested, as in the following PQL example.

result = MAP({
              expressions = [
                ['eif(id<10, true, eif(id>20,true,false))', 'id_test']
              ]           
            },
            nexmark:person
          )


Read(String path)

Reads the content of an arbitrary file and returns the content as a string.

Mem()

Returns the current used memory by the Java Virtual Machine in bytes.

Mem Example
SELECT mem() AS mem FROM stream
=> 230445616

Load()

Returns the current system load average for the last minute.

Load Example
SELECT load() AS load FROM stream
=> 2.77

Uptime()

returns the uptime of the Java Virtual Machine in milliseconds.

Uptime Example
SELECT uptime() AS uptime FROM stream
=> 481030

storedLine(String storage, Vector hierarchy, Vector row)

Returns the line stored in an associative storage given by the first parameter at the hierarchy given by the second parameter at the row given by the third parameter. 

SELECT storedLine("Storage", [123, 456], [3]) AS line FROM stream
=> [0,1,0,1,0]

storedValue(String storage, Vector hierarchy, Vector row)

 Returns the value stored in an associative storage given by the first parameter at the hierarchy given by the second parameter at the row given by the third parameter. 

SELECT storedValue("Storage", [123, 456], [3,2]) AS value FROM stream
=> 0

 

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