Aerospike: lua udf always returns an empty result even if udf return stream without any filtering, etc - lua

Question

Can not understand why aggregateQuery always returns an empty result. Tried to test in aql, the same problem: 0 rows in set.
Indexes are all there.
aql> show indexes
+---------------+-------------+-----------+------------+-------+------------------------------+-------------+------------+-----------+
| ns | bin | indextype | set | state | indexname | path | sync_state | type |
+---------------+-------------+-----------+------------+-------+------------------------------+-------------+------------+-----------+
| "test" | "name" | "NONE" | "profiles" | "RW" | "inx_test_name" | "name" | "synced" | "STRING" |
| "test" | "age" | "NONE" | "profiles" | "RW" | "inx_test_age" | "age" | "synced" | "NUMERIC" |
aql> select * from test.profiles
+---------+-----+
| name | age |
+---------+-----+
| "Sally" | 19 |
| 20 | |
| 22 | |
| 28 | |
| "Ann" | 22 |
| "Bob" | 22 |
| "Tammy" | 22 |
| "Ricky" | 20 |
| 22 | |
| 19 | |
+---------+-----+
10 rows in set (0.026 secs)
aql> AGGREGATE mystream.avg_age() ON test.profiles WHERE age BETWEEN 20 and 29
0 rows in set (0.004 secs)

Answer 1

It seems that you are trying the example here.
There are two problems about the udf script. I paste the code of the lua script :
function avg_age(stream)
local function female(rec)
return rec.gender == "F"
end
local function name_age(rec)
return map{ name=rec.name, age=rec.age }
end
local function eldest(p1, p2)
if p1.age > p2.age then
return p1
else
return p2
end
end
return stream : filter(female) : map(name_age) : reduce(eldest)
end
First, there is no bin named 'gender' in your set, so you got 0 rows after aggregateQuery.
Second, this script isn't doing exactly what the function name 'avg_age' means, it just return the eldest record with name and age.
I paste my code bellow, it just replace the reduce func, and alert the map and filter func to meat the demand. You can just skip the filter process.
function avg_age(stream)
count = 0
sum = 0
local function female(rec)
return true
end
local function name_age(rec)
return rec.age
end
local function avg(p1, p2)
count = count + 1
sum = sum + p2
return sum / count
end
return stream : filter(female) : map(name_age) : reduce(avg)
end
The output looks like bellow :
AGGREGATE mystream.avg_age() ON test.avgage WHERE age BETWEEN 20 and 29
+---------+
| avg_age |
+---------+
| 22 |
+---------+
1 row in set (0.001 secs)