I have an empty backing table and an OQGraph table pointing to it. When trying to run a SELECT query on the empty table, the query gets killed:

MariaDB [(none)]> use mydb
Database changed
MariaDB [mydb]> CREATE TABLE oq_backing (
-> origid INT UNSIGNED NOT NULL,
-> destid INT UNSIGNED NOT NULL,
-> PRIMARY KEY (origid, destid),
-> KEY (destid)
-> );
Query OK, 0 rows affected (0.40 sec)

MariaDB [mydb]> CREATE TABLE oq_graph (
-> latch VARCHAR(32) NULL,
-> origid BIGINT UNSIGNED NULL,
-> destid BIGINT UNSIGNED NULL,
-> weight DOUBLE NULL,
-> seq BIGINT UNSIGNED NULL,
-> linkid BIGINT UNSIGNED NULL,
-> KEY (latch, origid, destid) USING HASH,
-> KEY (latch, destid, origid) USING HASH
-> )
-> ENGINE=OQGRAPH
-> data_table='oq_backing' origid='origid' destid='destid';
Query OK, 0 rows affected (0.14 sec)

MariaDB [mydb]> SELECT * FROM oq_graph;
Killed