如何将索引添加到已创建的数据库中?
我是MYSQL的新手,并且在Django中建立了一个没有任何索引的数据库,这确实非常慢。
我正在尝试添加索引。问题是我需要按外键过滤。即使表不是很大(产品= 1百万,另一个是10k),查询仍然非常缓慢(思考20-25秒)。
这是我的Django代码:
class ScreenTwo(Screen):
def on_day_select(self,text): #Function assigns selected day from spinner to a variable
global day
day = str(text)
def on_hours_select(self,text): #Function assigns selected 12-hour from spinner to a variable
global hours
hours = int(text)
def on_minutes_select(self,text): #Function assigns selected minute from spinner to a variable
global minutes
minutes = int(text)
def on_AmPm_select(self,text): #Function assigns selected a.m/p.m from spinner to a variable
global AmPm
AmPm = str(text)
def hours_checking(self): #Function converts 12hr time to 24hr time
global AmPm
global hours
global minutes
global day
try:
if 1 <= hours <= 11 and AmPm == 'a.m':
pass
elif 1 <= hours <= 12 and AmPm == 'p.m':
hours += 12
elif hours == 12 and AmPm == 'a.m':
hours = 0
except:
print('error')
else:
print(day,hours,minutes)
pass
我应该在另一个表中的“ id”还是 product 表中的“另一个”列上建立索引吗?
我是否创建像这样的索引:
#large db (Product) filtered by foreign key (another__id)
Product.objects.filter(another__id='x')
由于这是在服务器上,我应该怎么做?