rt_mem_limit and search speed

Same query second time is fast.

MySQL [(none)]> SELECT id FROM la8_items_all WHERE MATCH('dog') AND (section != 3) AND (pushout_time < 1706261914) AND (sold_hammer_usd > 0) ORDER BY weight() desc LIMIT 78;
78 rows in set (19.519 sec)

MySQL [(none)]> show meta;
+----------------+--------+
| Variable_name  | Value  |
+----------------+--------+
| total          | 78     |
| total_found    | 165333 |
| total_relation | eq     |
| time           | 19.483 |
| keyword[0]     | dog    |
| docs[0]        | 230534 |
| hits[0]        | 356275 |
+----------------+--------+

MySQL [(none)]> SELECT id FROM la8_items_all WHERE MATCH('dog') AND (section != 3) AND (pushout_time < 1706261914) AND (sold_hammer_usd > 0) ORDER BY weight() desc LIMIT 78;
78 rows in set (0.055 sec)

MySQL [(none)]> show meta;
+----------------+--------+
| Variable_name  | Value  |
+----------------+--------+
| total          | 78     |
| total_found    | 165333 |
| total_relation | eq     |
| time           | 0.052  |
| keyword[0]     | dog    |
| docs[0]        | 230534 |
| hits[0]        | 356275 |
+----------------+--------+


cache is off

MySQL [(none)]> SHOW STATUS LIKE '%cache%';
+-----------------------+-------+
| Counter               | Value |
+-----------------------+-------+
| qcache_max_bytes      | 0     |
| qcache_thresh_msec    | 3000  |
| qcache_ttl_sec        | 1     |
| qcache_cached_queries | 0     |
| qcache_used_bytes     | 0     |
| qcache_hits           | 0     |
+-----------------------+-------+