Hi,
We have been using 5.6 for a long time with no big problems.
We have recently migrated to 5.7 (and a way more powerful server, with SSD and faster drives in the RAID), and we are seeing performance issues.
Most of the queries are taking a LOT more time than they used to on 5.6, on the same data.
We have many tables with 3-5 million records. A select count(*) from such a table used to finish in 2-5 seconds.
Example:
select count(*) from table_111;
+----------+
| count(*) |
+----------+
| 4908086 |
+----------+
1 row in set (3.92 sec)
On the server running 5.7 it looks like this:
select count(*) from osbp.cdrs_2016_11_12;
+----------+
| count(*) |
+----------+
| 4908086 |
+----------+
1 row in set (34.12 sec)
Both queries were ran without having the tables loaded in buffer.
On 5.7 the query appears as "optimizing" in process list.
We tried matching the settings on the 2 servers with no luck.
I saw 3 bugs opened on this topic and none had replies yet (ex:
https://bugs.mysql.com/bug.php?id=80191)
Did anybody else ran into similar problems with 5.7?