----- Original Message ----- > From: "Rik Wasmus" <r...@grib.nl> > > Depends on the data and usage, but probably I'd go for a index(a,b) & > index(b,a) if reads heavily outnumber writes. As index(a) is covered > by index(a,b), and index(b) by index(b,a), we don't need to add those, > which saves time on modifications.
I'm trying to think of a scenario where index(a) would be beneficial in the presence of index(a,b). If both are available, and all else being equal, it's likely that the parser will pick the simplest index; but I can't see it having a major impact. Any full prefix of a combined index may be used; so afaik a separate index on any full prefix is a waste of diskspace and cycles. The net conclusion, Neil, is that you actually have to know what you're doing :-) Take the time to read the online documentation on mysql.com, it's pretty good. -- Bier met grenadyn Is als mosterd by den wyn Sy die't drinkt, is eene kwezel Hy die't drinkt, is ras een ezel -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org
