Querying on key of a Map in Aerospike

Question

I'm trying to store a map in aerospike and fetch the data based on the key of the map.

First I created a Index on the bin where i'm storing the map

 aql> create mapkeys index status on test.myset (state) String
 aql> show indexes
+--------+---------+-----------+---------+-------+-----------+---------+------------+----------+
| ns     | bin     | indextype | set     | state | indexname | path    | sync_state | type     |
+--------+---------+-----------+---------+-------+-----------+---------+------------+----------+
| "test" | "state" | "MAPKEYS" | "myset" | "RW"  | "status"  | "state" | "synced"   | "STRING" |
+--------+---------+-----------+---------+-------+-----------+---------+------------+----------+
1 row in set (0.000 secs)
OK

Then I used java client to store the map

AerospikeClient client = new AerospikeClient("127.0.0.1",3000);

    WritePolicy writePolicy = new WritePolicy();
    writePolicy.timeout=500;

    for(int i = 1;i<10;i++){
        Key key = new Key("test","myset",""+i);
        client.delete(writePolicy, key);

        HashMap<String,String> map = new HashMap<String,String>();
        map.put("key1", "string1");
        map.put("key2", "string2");
        map.put("key3", "string3");

        Bin bin = new Bin("state", map);
        client.put(writePolicy, key, bin);

    }

I checked the data through apl and the data is clearly present.

aql> select * from test.myset
+--------------------------------------------------------+
| state                                                  |
+--------------------------------------------------------+
| {"key1":"string1", "key2":"string2", "key3":"string3"} |
| {"key1":"string1", "key2":"string2", "key3":"string3"} |
| {"key1":"string1", "key2":"string2", "key3":"string3"} |
| {"key1":"string1", "key2":"string2", "key3":"string3"} |
| {"key1":"string1", "key2":"string2", "key3":"string3"} |
| {"key1":"string1", "key2":"string2", "key3":"string3"} |
| {"key1":"string1", "key2":"string2", "key3":"string3"} |
| {"key1":"string1", "key2":"string2", "key3":"string3"} |
| {"key1":"string1", "key2":"string2", "key3":"string3"} |
| {"key1":"string1", "key2":"string2", "key3":"string3"} |
+--------------------------------------------------------+
10 rows in set (0.019 secs)

Now when I try to query based on the index created it gives

aql> select * from test.myset where status = 'key1'
0 rows in set (0.000 secs)
Error: (204) AEROSPIKE_ERR_INDEX

aql> select * from test.myset where state = 'key1'
0 rows in set (0.000 secs)
Error: (201) AEROSPIKE_ERR_INDEX_NOT_FOUND

Can someone help me with this. I searched for that error but found no information. Thank you.

Before we dig deeper, did you mean to do `where state =` instead of `where status =` ? — RavenMan, Apr 03 '16 at 23:23
@Aaron, i tried using state and it is giving a different error. Updating the question accordingly. — Pardha.Saradhi, Apr 04 '16 at 06:24

score 6 · Accepted Answer · answered Apr 06 '16 at 07:52

Secondary indexes on MapKeys, MapValues, Lists are supported by Aerospike, apart from Numeric, String and Geo2DSphere types.

For your scenario, you can query on the Mapkey as follows.

select * from test.myset in mapkeys where state='key1'

This should return the results.

In AQL, if you type help, you should get the following for queries

    SELECT <bins> FROM <ns>[.<set>]
    SELECT <bins> FROM <ns>[.<set>] WHERE <bin> = <value>
    SELECT <bins> FROM <ns>[.<set>] WHERE <bin> BETWEEN <lower> AND <upper>
    SELECT <bins> FROM <ns>[.<set>] WHERE PK = <key>
    SELECT <bins> FROM <ns>[.<set>] IN <indextype> WHERE <bin> = <value>
    SELECT <bins> FROM <ns>[.<set>] IN <indextype> WHERE <bin> BETWEEN <lower> AND <upper>

Similarly, you can run a query for the MapValue as well.

RavenMan · Answer 2 · 2016-05-18T01:52:24.853

Update:

As of Aerospike 3.8.1, Secondary Index on List and Map are officially supported.

Original Response:

Query by secondary index on map keys, map values, or list values are not officially supported yet.

That said, the functionality and syntax is somewhat available. You need to:

Create a secondary index with type MAPKEYS, MAPVALUES or LIST (you're using type STRING at the moment)
Select as follows (you're missing the IN MAPKEYS part):

SELECT * FROM namespace.setname IN MAPKEYS WHERE bin = 'keyValue'

The query syntax, as well as some other bits, is available if you type help while in the AQL console.

Querying on key of a Map in Aerospike

2 Answers2