less than greater than filtered queries, aerospike

Question

Its been hard for me to find finite documentation on aerospike. Using aerospike filters with or without lua, is it possible for me to :

Order my results server side
Use a filter to do a greater than/less than query

Essentially I want to encode a value(client side) and retrieve the first row from aerospike whos value is greater than the encoded one.

Another way to put it, is opposite of price is right... what is the lowest value i can find in aerospike, whos value is not lower than the one i give.

Id like a simple way, but I am also open to work arounds(or flat out no if its not reasonable/practical)

score 3 · Answer 1 · answered Apr 24 '14 at 06:54

3

Aerospike does not natively support ordering of data on server-side.
Aerospike supports filters on the query. You can specify a range filter for your need. See the example at this link.

answered Apr 24 '14 at 06:54

sunil

3,507
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MrBar · Answer 2 · 2015-11-23T07:07:59.917

Basic Sorting is natively supported in large lists (LDT).

In a Large List your key (index) is always ordered in a lexical manner by default.

Please notice that ldt-enabled true directive must be present in the namespace's config area in aerospike.conf

an example with the javascript client

var key = {ns: 'test', set: 'mySet', key: 'myKey'};
var callback = function (status, result) {console.log(status, result)}

var list = client.LargeList(key, 'targetBinName', null, callback));

// add first item (also determinate the list values type) 
list.add(1, callback);

// add multiple items
list.add([0, 2, 4, 5], callback);

list.add(3, callback);

// get all items
list.scan(function (status, list) {
     // list = [0, 1, 2, 3, 4, 5]
})

// select by values range
list.findRange(0, 3, callback)

// filter using udf to do custom gt/lt filtering
list.filter('udfName', callback)

if you need to store objects then you must add a key property that will be the index for sorting, range, duplicates etc (no duplicates are allowed by default)

list.add({key: 1})
list.add([{key: 0},{key: 2}])

I'm sure the other languages drivers have the same methods more or less.

less than greater than filtered queries, aerospike

3 Answers3