Menambahkan juga, jangan langsung menambahkan index hanya karena ingin mempercepat query. Biasanya index dipakai pada kolom2 yg memang sering diakses aplikasi. Jadi ketika query kita mengakses data tanpa index, coba cek dulu apakah query itu telah benar? Mungkinkah ada cara lain? Tentu saja tidak tertutup kemungkinan kalau developer lupa membuat index yg seharusnya diperlukan.
Terkadang query yg lambat bisa ditoleransi, mungkin karena hanya dijalankan sehari sekali pada non-peak hour, atau mungkin menambahkan index memberikan impact yg lumayan terhadap dml. regards, tomi --- Yoel <[EMAIL PROTECTED]> wrote: > diambil dari emailnya Mr. J sebelumnya > > Ordering Keys for Composite Indexes > Follow these guidelines for ordering keys in > composite indexes: > 1. Create the index so the keys used in WHERE > clauses make up a leading > portion. > 2. If some keys are used in WHERE clauses more > frequently, then be sure to > create > the index so that the more frequently selected keys > make up a leading > portion > to allow the statements that use only these keys to > use the index. > 3. If all keys are used in WHERE clauses equally > often, then ordering these > keys > from most selective to least selective in the CREATE > INDEX statement best > improves query performance. > 4. If all keys are used in the WHERE clauses equally > often but the data is > physically > ordered on one of the keys, then place that key > first in the composite > index. > > On 10/5/06, jimmy <[EMAIL PROTECTED]> wrote: > > > > Bagaimana ya cara menentukan kolom2 mana yang > harus di > > index sesuai dengan query yang kita buat ? > > Misalkan kita membuat suatu query, trus kita harus > > membuat index yang seperti bagaimana, supaya query > > kita itu cepat. > > Ada nggak ya panduan tentang hal ini ? > > > > Terima kasih sebelumnya. > > > > Salam, > > Jimmy __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com -- -----------I.N.D.O - O.R.A.C.L.E--------------- Keluar: [EMAIL PROTECTED] Website: http://indo-oracle.blogspot.com Mirror: http://indooracle.wordpress.com ----------------------------------------------- Bergabung dengan Indonesia Thin Client User Groups, Terminal Server, Citrix, New Moon Caneveral, di: http://indo-thin.blogspot.com Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/indo-oracle/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/indo-oracle/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
