COUNT(1) VS COUNT(*) - ANY DIFFERENCE?
A while ago when I started my first job in LA, I was using MSSQL. I was told to never use count(), and rather to use count(1). Several people insisted this performs better than count(), and since I really didn’t care to argue or look into it, I just started doing it. Fast forward to today, where I am still writing count(1), but on MySQL. I’m at a different company now, but working with...
WHY HAVE REPLACE INTO AND INSERT ... ON DUPLICATE KEY UPDATE?
REPLACE INTO will actually perform a delete and then an insert, while INSERT … ON DUPLCIATE KEY UPDATE will perform an update (as the name suggests). I would think the latter would be faster. I have not done any performance testing between the two, but it only seems logical the update would be faster than the delete/insert. Please correct me if I’m wrong. Since the two statements both...
ANSWERBAG READ WRITE API NOW IN BETA
Although it’s not officially announced, our read/write api is now out and in beta. It’s not officially launched on the site or anything, but we are looking for interested partners. Docs are here
PUBLIC AND PRIVATE KEYS OVER SSH
I found a very good explanation of how to set up public key authentication over ssh. I’m always looking for it when I need it, and it always takes forever. http://www.petefreitag.com/item/532.cfm You can also use ssh-copy-id, I’m not sure what the specifics are behind it, but it seems to be available occasionally (Fedora 6) and not in other places (OS X 10.4.8).
PAGING THROUGH DATA 2.0
For a long time, whenever I wanted to do paging to browse through a table, I used to run 2 queries. The first would get the results, and the second would be an almost identical query, with a count() instead of fields, and I’d use the result of the second query to figure out how many pages I would need. Now there’s a better solution, and it’s called found_rows(). Say you have a...
CALLING A FUNCTION FROM WITHIN PREG_REPLACE
Regular expressions are awesome. However, sometimes doing everything in them is extremely difficult, or impossible. Luckily, we can flex the power of preg_replace’s ’e’ option to execute the replacement string as PHP code. The reason why I found this is was I was looking for a suitable URL auto-linker that could shorten the url to a certain length. I found several examples on...
PRETTY URLS USING MULTIVIEWS
I saw a post on digg.com about how it’s nice to have “pretty urls” that are easy to tell people. While i’m not sure anyone would remember rustyrazorblade.com slash some ridiculous post name, it’s nice to have for search engines. Unfortunately, it didn’t really go into detail about how to accomplish the urls. A lot of people suggested mod_rewrite. Yes, it’s...
CAN YOU USE A STORED PROCEDURE IN A SUBQUERY? I DON'T THINK SO. (MYSQL)
I do not think you can use the result of a stored procedure in an ad-hoc subquery. On my social network, LetsGetNuts.com, I have a Friend table. This is the structure: mysql> describe Friend; +—————-+—————+——+—–+———+——-+ | Field | Type | Null | Key | Default | Extra |...
'POST-DIGGING: ASKHADDAD.COM'
Glad I was able to think of something interesting enough for the digg community to vote up so highly, but I was a little surprised to see that question submission has completely stopped. I’ve been sitting at 388 all weekend. It was interesting to see traffic spike up to 67K pageviews for the day - it was mostly contained in a period of 5 hours. Also funny to see people try to mess with the...
ASKHADDAD.COM
I’ve created an experiment, askhaddad.com. I answer all questions in the order they are received, unless they are blatent spam or nonsense. Askhaddad.com is an anti-social q&a; site - there is no user community, and I am the only one that answers questions.