er, finished that last sentence this time.... On 8/1/08, Sheeri K. Cabral <[EMAIL PROTECTED]> wrote: > > On 8/1/08, Brian Aker <[EMAIL PROTECTED]> wrote: >> >> >> On Aug 1, 2008, at 3:46 PM, Josh Berkus wrote: >> >> How would you handle a large set of flags then? BOOL columns? >>> >> >> >> We have a BIT type, but it really is an 1 byte int in the memory format >> (aka what we pass around). >> >> It is up to an engine to decide how it wants to store it. Right now in >> Drizzle no engine does this (and MyISAM in theory could but it will take >> some rework). >> >> So right now BIT is just an ALIAS really to saying TINYINT. >> >> The operators though operate on any type. > > > I've done pretty interesting things with bitstrings due to MySQL's not > handling many flags very well, but that's a huge hack and involves > hard-coding what each position in the bitstring means. > > I think for handling, using ENUM/SET is appropriate (though it may also be > easy enough to alias BIT to be an ENUM if you really want). > > As for operators, I'm guessing you mean the ~, !, |, &, <<, >>, and > groupwise BIT_AND() and BIT_OR() and BIT_XOR(). Given the complete > brokenness in the way the BIT_AND() function handles NULL ( > http://bugs.mysql.com/bug.php?id=37754), I doubt very many people use it. > And given my experience, very very very few people use bits unless they're > flagging something.... > > ...and even then about 6 months later they realize that they need more than > 2 values. > > I don't believe anyone in Drizzle's target audience is doing bitwise math > in the database, including left and right shifts, and especially not the > groupwise functions. I can see it coming in handy with >
IP addresses, but given there will be a custom field type of IP addresses, I don't think there's much of an issue there. -Sheeri >
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