How to Query a Table for a Random Sample of Records

Consider the table supplier which contains 10,000 records:

memsql> select count(*) from supplier;
+----------+
| count(*) |
+----------+
|    10000 |
+----------+
1 row in set (0.12 sec)

I can randomly select ~50% of the records in this table using the following query: 

memsql> select count(*) from supplier where RAND() < .5;
+----------+
| count(*) |
+----------+
|     5071 |
+----------+
1 row in set (0.00 sec)

I can randomly select ~10% of the records in this table using the following query: 

memsql> select count(*) from supplier where RAND() < .1;
+----------+
| count(*) |
+----------+
|      975 |
+----------+
1 row in set (0.00 sec)