Code review comment for lp:~laurynas-biveinis/percona-server/ahi-partitions-5.6-5.6

> More comments on test cases:
...
> I don’t know the purpose of all these checks which are replicated from
> one test case to another. It looks like some incompetent (to put it
> mildly) person first wrote them, and then everyone else copies that
> stuff whenever he needs to implement a variable test.
>
> What I would expect to see in a sys_var.*_basic test is verifying
> the variable type, and default/min/max values. Instead most tests do
> some acrobatics with I_S and different syntax to access the variable.

I absolutely agree with all these comments and obviously I have cut some corners when copied/pasted/modified it.

What do you think about the following? The variable is global-only, read-only. Check the default, check the read-only-ness, check that global only. For 5.5 too.

# A sys_vars suite test from innodb_adaptive_hash_index_partitions.

--source include/have_innodb.inc

SELECT @@GLOBAL.innodb_adaptive_hash_index_partitions;

--error ER_INCORRECT_GLOBAL_LOCAL_VAR
SET @@GLOBAL.innodb_adaptive_hash_index_partitions=1;

--error ER_INCORRECT_GLOBAL_LOCAL_VAR
SELECT @@LOCAL.innodb_adaptive_hash_index_partitions;

--error ER_INCORRECT_GLOBAL_LOCAL_VAR
SELECT @@SESSION.innodb_adaptive_hash_index_partitions;