In MySQL, this is perfectly valid:
set @t = @@group_concat_max_len;
set @@group_concat_max_len = @t;
In Single Store, the second assignment fails with this error
SQL Error [1064] [42000]: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘@t’ at line 1
None of these syntaxes work, either:
set @@group_concat_max_len = (select @t);
select @t into @@group_concat_max_len;
I can only assign constants to that flag, it seems:
set @@group_concat_max_len = 1234;
I’m using the latest version from docker hub:
https://hub.docker.com/r/singlestore/cluster-in-a-box
Which corresponds to the tag alma-7.8.9-e94a66258d-4.0.7-1.13.9