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Old Pedant · 02-07-2013, 03:20 AM

What is "Toxi"? Where did that come from?

Wherever, it's also the properly normalized version.

If you truly have the limitations you specified and you 100%-promise-to-delete-the-entire-site-if-you-change-your-mind-kind-of-sincerity that those limitations won't changed, then a little bit of denormalization as you propose would surely not hurt.

Would it help? I tend to doubt it.

I would like to point out that if you do denormalize then there are several possible future queries that get tougher. Example:
"How many bookmarks use both tag13 and tag93?"
[WHERE (tag1=13 AND tag2=93) OR (tag1=93 AND tag2=13)]
[ugh!]

"How many bookmarks have only one tag?"
[WHERE (tag1 IS NOT NULL AND tag2 IS NULL) OR (tag1 IS NULL AND tag2 IS NOT NULL]
[double ugh!]

"How many bookmarks use exactly the same two tags as another bookmark?"
[much more code than I want to show]

All those--and more--are trivial in the fully normalized ("Toxi") case.

02-07-2013, 03:20 AM	PM User \| #2
Old Pedant Supreme Master coder! Join Date: Feb 2009 Posts: 23,200 Thanks: 59 Thanked 3,996 Times in 3,965 Posts	What is "Toxi"? Where did that come from? Wherever, it's also the properly normalized version. If you truly have the limitations you specified and you 100%-promise-to-delete-the-entire-site-if-you-change-your-mind-kind-of-sincerity that those limitations won't changed, then a little bit of denormalization as you propose would surely not hurt. Would it help? I tend to doubt it. I would like to point out that if you do denormalize then there are several possible future queries that get tougher. Example: "How many bookmarks use both tag13 and tag93?" [WHERE (tag1=13 AND tag2=93) OR (tag1=93 AND tag2=13)] [ugh!] "How many bookmarks have only one tag?" [WHERE (tag1 IS NOT NULL AND tag2 IS NULL) OR (tag1 IS NULL AND tag2 IS NOT NULL] [double ugh!] "How many bookmarks use exactly the same two tags as another bookmark?" [much more code than I want to show] All those--and more--are trivial in the fully normalized ("Toxi") case. __________________ An optimist sees the glass as half full. A pessimist sees the glass as half empty. A realist drinks it no matter how much there is.