List Indexing and Querying

Aerospike allows users to create a secondary index on bins whose data type is a list.

Indexing on List Elements

• Similar to basic indexing, the indexable list element data types are numeric, string, and GeoJSON.
• You can index a List at any depth. Prior to Database 6.1, list indexing was only on the top-level element, not nested elements.
• When creating and index, specify explicitly that list bins should be indexed, and what data type to index on.
• When querying, specify that the query should be applied on a CDT data type.
• Similar to basic querying, equality, range (for numeric and string data type), points-within-region, region-containing-points (for GeoJSON data type) are supported.

In this example we use the asadm tool to create two indexes on a single LIST, one for values in the list with numeric data type, one for values in the list with string data type. For further instructions, see Secondary Index (SI) Query.

Admin+> manage sindex create numeric foo_list_int in list ns test set demo bin foo
Admin+> manage sindex create string foo_list_string in list ns test set demo bin foo

Elements of the indexed list are type checked, so a record whose foo bin contains [ 1, "2", 3, [4], 5 ] results in the following indexing:

Index On	Key Type	Index Type	Eligible Secondary Index Key
foo	string	LIST	"2"
foo	numeric	LIST	1, 3, 5

List Index Queries

The following example uses the aql tool to query an indexed list.

aql> INSERT INTO test.demo (PK, username, emails) VALUES ("u1", "Bob Roberts", LIST('["bob.roberts@gmail.com", "bob@yahoo.com"]'))
OK, 1 record affected.

aql> INSERT INTO test.demo (PK, username, emails) VALUES ("u2", "rocketbob", LIST('["bigb@gmail.com", "bob@yahoo.com"]'))
OK, 1 record affected.

aql> INSERT INTO test.demo (PK, username, emails) VALUES ("u3", "samunwise", "pppreciousss@gmail.com")
OK, 1 record affected.

aql> CREATE LIST INDEX email_idx ON test.demo (emails) STRING
OK, 1 index added.

aql> show indexes
+--------+----------+-----------+--------+-------+-------------+----------+----------+
| ns     | bin      | indextype | set    | state | indexname   | path     | type     |
+--------+----------+-----------+--------+-------+-------------+----------+----------+
| "test" | "emails" | "LIST"    | "demo" | "RW"  | "email_idx" | "emails" | "STRING" |
+--------+----------+-----------+--------+-------+-------------+----------+----------+
[127.0.0.1:3000] 1 row in set (0.001 secs)

OK

aql> SELECT username FROM test.demo IN LIST WHERE emails = "bigb@gmail.com"
+-------------+
| username    |
+-------------+
| "rocketbob" |
+-------------+
1 row in set (0.001 secs)

OK

aql> SELECT username FROM test.demo IN LIST WHERE emails = "bob@yahoo.com"
+---------------+
| username      |
+---------------+
| "Bob Roberts" |
| "rocketbob"   |
+---------------+
2 rows in set (0.001 secs)

OK

aql> SELECT username FROM test.demo IN LIST WHERE emails = "pppreciousss@gmail.com"
0 rows in set (0.001 secs)

OK

aql> SELECT username FROM test.demo WHERE emails = "pppreciousss@gmail.com"
0 rows in set (0.001 secs)

Error: (201) AEROSPIKE_ERR_INDEX_NOT_FOUND

Known Limitations

• When using range queries on lists, records can be returned multiple times if the list contains multiple values that fall within the range.