Kalau semua statistik antara index 1 dan 3 sama, ya tidak masalah toh oracle mau pilih yg mana utk dipakai. Kemungkinan sih pilih index berdasarkan mana yg dibuat lebih dulu atau berdasarkan urutan abjad (gak yakin sih, perkiraan doang).
Kalau saya pribadi sih, seandainya akses lewat index 1 dan 3 sama costnya, tetapi index 3 jumlah kolomnya lebih sedikit dibanding index 1 (6 vs 3), mending gue pilih index 3 sih. Bukankah membandingkan 3 kolom lebih cepat dibandingkan 6 kolom :).. Kembali ke kasus anda, sebenarnya index yg Anda buat ngasal doang atau memang berdasarkan kebutuhan aplikasi??? Index yg tidak efektif hanya menghabiskan space dan terkadang mengganggu optimizer utk mendptkan exec plan yg optimal. regards, tomi --- J <[EMAIL PROTECTED]> wrote: > select > table_name,index_name,num_rows,distinct_keys,avg_leaf_blocks_per_key,avg_data_blocks_per_key,clustering_factor > from dba_indexes where owner='SAUDI6' and index_name > like > 'IDX_ITM_COST_MNTH%'; > ITEM_COST_MONTH IDX_ITM_COST_MNTH1 57275 > 49271 1 1 > 39909 > ITEM_COST_MONTH IDX_ITM_COST_MNTH2 57275 > 45292 1 1 > 41034 > ITEM_COST_MONTH IDX_ITM_COST_MNTH3 57275 > 49271 1 1 > 39909 > ITEM_COST_MONTH IDX_ITM_COST_MNTH4 57275 > 22 9 35 > 780 > > ada alasan lain kenapa si oracle keukeuh milih > IDX_ITM_COST_MNTH3 ? > index clustering factor nya sama aja........... > > --J > > > > > Kalau exec plan Anda mengakses table melalui > index, > > maka statistics CLUSTERING_FACTOR di index sangat > > mempengaruhi COST. Semakin kecil nilainya, semakin > > kecil total cost, dan semakin besar kemungkinan > index > > tsb dipakai. > > __________________________________________________ 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/
