April 2020
Beginner to intermediate
540 pages
14h 14m
Russian
Content preview from MongoDB: полное руководство
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Знакомство с индексами 147
]
}
}
]
}
}
},
"rejectedPlans": []
},
"serverInfo": {
...,
},
"ok": 1
}
Как видите, здесь нам потребовалось два отдельных запроса по двум ин-
дексам (как обозначено двумя этапами
"IXSCAN"). В целом делать два запро-
са и объединять результаты гораздо менее эффективно, чем выполнять
один запрос; таким образом, по возможности, лучше используйте опера-
тор
"$in" вместо "$or".
Если вам необходимо использовать оператор "$or", помните, что Mon-
goDB нужно просмотреть результаты обоих запросов и удалить все дубли-
каты (документы, которые соответствуют более чем одному оператору
"$or").
При выполнении запросов с "$in" ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.