Over time, some options have crept into the MySQL server which are comma separated lists of options. These include SQL_MODE, optimizer_switch, optimizer_trace and a few other variables.

Optimizer_switch is particularly problematic to work with as it contains many options and is hard to interpret. This is what you usually see when you examine optimizer_switch:

index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=on,mrr=on,mrr_cost_based=on,block_nested_loop=on,batched_key_access=off,materialization=on,semijoin=on,loosescan=on,firstmatch=on,subquery_materialization_cost_based=on,use_index_extensions=on

As you can see, seeing which option is on or off is rather difficult. You can use the REPLACE function to make this easier:

mysql> select replace(@@optimizer_switch, ',','\n')\G …

Over time, some options have crept into the MySQL server which are comma separated lists of options. These include SQL_MODE, optimizer_switch, optimizer_trace and a few other variables.

Optimizer_switch is particularly problematic to work with as it contains many options and is hard to interpret. This is what you usually see when you examine optimizer_switch:

index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=on,mrr=on,mrr_cost_based=on,block_nested_loop=on,batched_key_access=off,materialization=on,semijoin=on,loosescan=on,firstmatch=on,subquery_materialization_cost_based=on,use_index_extensions=on

As you can see, seeing which option is on or off is rather difficult. You can use the REPLACE function to make this easier:

mysql> select replace(@@optimizer_switch, ',','\n')\G …

Enter the sb script (available in version 3.0.03). Now I can shorten my typing experience with sandboxes quite a lot:

  $ sb 5135
  # same as calling 
  # …

During my day-to-day activities, I use the Bash shell a lot. My #1 policy is to optimize the most frequently used activities as much as possible, so Iâ€ve compiled these handy bash shortcuts and hints (tested in SecureCRT on Windows and Konsole on Linux). The article only touches on the default bash mode – emacs, not vi. If you havenâ€t specifically assigned your shell mode to vi (set –o vi), youâ€re almost certainly using the emacs mode. Learn these and your shell productivity will skyrocket, I guarantee it.

Update #1: In response to a few people saying this list is too short and “[he] could've added something to it, to atleast make it look longer†(quote from one of Stumbleupon reviewers), I want to clarify something. I deliberately did not include …