Skip to content

# Variables ambiguities in names and values

MySQL Configuration April 28, 2009April 28, 2009

Writing up some scripts, I see more and more ambiguities with regard to global variables.

For one thing, the names ambiguity between the hyphen (‘-‘) and the underscore (‘_’). So wait_timeout and wait-timeout are the same variable.

But just check out the many levels of inconsistency:

- Command line arguments (e.g. run mysqld with option variables) use the hyphen convention
- mysql –verbose –help shows the hyphen convention
- SHOW GLOBAL VARIABLES uses the underscore convention
- The MySQL supplied sample configuration files use both conventions interchangeably

Enough? Not quite: there are ambiguities in values, as well. For example, you may set query_cache_type to 1 or ON. These are equivalent. That’s very friendly. However:

- mysql –verbose –help will show “query_cache_type 1“
- SHOW GLOBAL VARIABLES will show “query_cache_type ON“

We also have:

- 1 <==> YES
- OFF <==> FALSE
- ON <==> TRUE

Time to decide. Ambiguities are evil. They make for a difficult parsing/analysis/comparison/validation work. Will anyone pick the glove?

PS – Drizzle falk – isn’t this the kind of stuff you’re happy to drop?

- Twitter
- LinkedIn
- WhatsApp
- Email
- Facebook
- Print

###
6
Leave a Reply

6 Comment threads
0 Thread replies
0 Followers
Most reacted comment
Hottest comment thread
5 Comment authors
Recent comment authors

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Subscribe
Notify of
Guest
ahmad

you are right. there should be a standard for this.

Guest
Pavel

Thanks for the post. Before I got used to the ambiguity, I kept looking into the docs. Having a single notation would be something to look forward to in both drizzle and mysql.

Guest
Devananda

Yes, this has annoyed me too, particularly early on. There’s a discussion right now about refactoring the configuration management for Drizzle into a plugin, hopefully fixing this can be included in that project 🙂

Guest
Jay Pipes

Hi! Yep, the Drizzle community, as Devananda mentioned, is currently discussing this. The thread in questions starts here:

https://lists.launchpad.net/drizzle-discuss/msg03804.html

Cheers!

Jay

INFORMATION_SCHEMA.GLOBAL_STATUS: watch out | code.openark.org

[…] There are a few ON/OFF values (I’ve expressed my opinion and concerns on these here and here; why not just use 0/1?). SSL_CIPHER seems like the only variable which can get long enough […]

Guest
Rick James

The programming public is Boolean-challenged. I get so irritated every time I see (in any of several languages)
if () x = TRUE else x = FALSE;

The equivalence of 0/false/off and 1/true/on will be hard to ‘teach’, regardless of which way you go.

I do agree that consistency would be nice. Fortunately, MySQL is usually forgiving.

Another frustration: The flags that are done by there presence/absence, perhaps including
log-slave-updates
skip-external-locking

wpDiscuz
Send to Email Address Your Name Your Email Address Cancel
Post was not sent - check your email addresses!
Email check failed, please try again
Sorry, your blog cannot share posts by email.