November 2021
Intermediate to advanced
410 pages
12h 1m
Chinese
Content preview from MongoDB权威指南（第3版）
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了解应用程序的动态
｜
315
"nindexes" : 5,
"indexBuilds" : [ ],
"totalIndexSize" : 46292992,
"indexSizes" : {
"_id_" : 446464,
"$**_text" : 44474368,
"genres_1_imdb.rating_1_metacritic_1" : 724992,
"tomatoes_rating" : 307200,
"getMovies" : 339968
},
"scaleFactor" : 1,
"ok" : 1
}
stats
的返回结果中首先是命名空间（
"sample_mflix.movies"
），然后是集合中所有文档
的计数。接下来的两个字段与集合的大小有关。如果对集合中的每个元素调用
Object.
bsonsize()
并将所有结果相加，就会得到
"size"
的值：它是集合中的文档在未压缩时占用
内存的实际字节数。同样，如果将
"avgObjSize"
和
"count"
相乘，也可以得到内存中未压
缩的
"size"
值。
正如前面所提到的，文档字节总数会忽略压缩集合所节省的空间。而
"storageSize"
是一
个比
"size"
更小的值，可以反映出压缩所节省的空间。
"nindexes"
是集合中索引的个数。索引在创建完成后才会被计算在
"nindexes"
中，并且只
有出现在这个列表中之后才可以被使用。通常，索引会比它们存储的数据量大很多。可以
使用右平衡索引来最小化这个空闲空间（参见 ...
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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.