Agregatsiya va oyna funksiyalari

Bazani yoqish: baza-start (har lab boshida server o'chiq bo'ladi). psql'ga kirish: hn (bu psql -h /tmp -U postgres -d hn uchun qisqartma; fayl bajarish: hn -f fayl.sql, bitta so'rov: hn -c "..."). sotuv(id, mahsulot, viloyat, kun, summa) — determinatsiyalangan seed (checker natijani AYNAN solishtiradi, qator/ustun tartibi ham muhim). Vazifa (/root/db/) q1.sql — viloyat ichida reyting: viloyat, mahsulot, summa, rank() ..., dense rank() ... (ikkalasi partition by viloyat order by summa desc), tashqi tartib: viloyat, summa desc, mahsulot. q2.sql — kunlik jami bo'yicha dinamika: har kun uchun kun, jami, uch kunlik siljuvchi o'rtacha — round(avg(jami) over (order by kun rows between 2 preceding and current row)::numeric, 2) (darsdagi ::numeric majburiy!) va yig'iluvchi jami (rows between unbounded preceding and current row), kun tartibida. Kunlik jami — ichki so'rovda group by kun. q3.sql — distinct on (mahsulot): har mahsulotning ENG OXIRGI sotuvi: mahsulot, kun, summa, order by mahsulot, kun desc. Muvaffaqiyat mezoni Uchala natija jonli referens bilan AYNAN mos; q1da dense rank, q2da preceding, q3da distinct on bo'lishi shart.