db.collection.stats()
在本页面
Definition
db.collection.stats(比例尺|选项)- 返回有关集合的统计信息。该方法包括以下参数：
| Parameter | Type | Description |
|---|---|---|
scale |
number | 可选的。输出中用于显示项目大小的比例。默认情况下，输出以bytes显示大小。要显示千字节而不是字节，请指定scale值1024。 |
在版本 3.0 中更改：旧版参数格式。与 options作为文档互斥。 |
||
options |
文档 | 可选。替代scale参数。使用options文档指定选项，包括scale。3.0 版中的新功能。 |
options文档可以包含以下字段和值：
| Field | Type | Description |
|---|---|---|
scale |
number | 可选的。输出中用于显示项目大小的比例。默认情况下，输出以字节为单位显示大小。要显示千字节而不是字节，请指定scale值1024。 |
3.0 版中的新功能。
| indexDetails |布尔值|可选。如果是true，则db.collection.stats()除了返回集合统计信息外，还会返回index details。
仅适用于WiredTiger存储引擎。
默认为false。
3.0 版中的新功能。
| indexDetailsKey |文档|可选。如果indexDetails是true，则可以使用indexDetailsKey通过指定索引键规范来过滤索引详细信息。仅返回与indexDetailsKey完全匹配的索引。
如果找不到匹配项，indexDetails将显示所有索引的统计信息。
使用getIndexes()查找索引键。您不能将indexDetailsKey与indexDetailsName结合使用。
3.0 版中的新功能。
| indexDetailsName |字符串|可选。如果indexDetails是true，则可以使用indexDetailsName通过指定索引name来过滤索引详细信息。仅返回与indexDetailsName完全匹配的索引名称。
如果找不到匹配项，indexDetails将显示所有索引的统计信息。
使用getIndexes()查找索引名称。您不能将indexDetailsName与indexDetailsField结合使用。
3.0 版中的新功能。
db.collection.stats()方法提供了围绕数据库命令collStats的包装。
Behavior
此方法返回具有与当前mongod实例相关的统计信息的 JSON 文档。除非键名另外指定，否则与大小相关的值以字节显示，并且可以被scale覆盖。
Note
比例因子将值四舍五入为整数。
根据存储引擎的不同，返回的数据可能会有所不同。有关字段的详细信息，请参见output details。
意外关机后的准确度
使用Wired Tiger存储引擎对mongod进行异常清除后，db.collection.stats()报告的计数和大小统计信息可能不准确。
漂移量取决于在最后一个checkpoint和不正常关机之间执行的插入，更新或删除操作的数量。检查点通常每 60 秒出现一次。但是，以非默认--syncdelay设置运行的mongod实例可能具有或多或少的频繁检查点。
在异常关闭后，对mongod上的每个集合运行validate以恢复正确的统计信息。
索引过滤器行为
使用indexDetailsKey或indexDetailsName在indexDetails上进行过滤只会返回一个匹配的索引。如果未找到完全匹配的内容，indexDetails将显示有关该集合的所有索引的信息。
indexDetailsKey字段采用以下格式的文档：
{ '<string>' : <value>, '<string>' : <value>, ... }
其中<string>>是要索引的字段，而<value>是索引的方向或特殊的索引类型，例如text或2dsphere。有关索引类型的完整列表，请参见index types。
意外关机和计数
对于使用WiredTiger存储引擎的 MongoDB 实例，在异常关闭后，如collStats，dbStats，count所报告的，大小和计数统计信息可能多达 1000 个。要恢复集合的正确统计信息，请在集合上运行validate。
Examples
Note
您可以在我们的入门指南中找到用于这些示例的收集数据
基本统计信息查询
以下操作返回restaurants集合的统计信息：
db.restaurants.stats()
该操作返回：
{
"ns" : "guidebook.restaurants",
"count" : 25359,
"size" : 10630398,
"avgObjSize" : 419,
"storageSize" : 4104192
"capped" : false,
"wiredTiger" : {
"metadata" : {
"formatVersion" : 1
},
"creationString" : "allocation_size=4KB,app_metadata=(formatVersion=1),block_allocation=best,block_compressor=snappy,cache_resident=0,checksum=on,colgroups=,collator=,columns=,dictionary=0,encryption=(keyid=,name=),exclusive=0,extractor=,format=btree,huffman_key=,huffman_value=,immutable=0,internal_item_max=0,internal_key_max=0,internal_key_truncate=,internal_page_max=4KB,key_format=q,key_gap=10,leaf_item_max=0,leaf_key_max=0,leaf_page_max=32KB,leaf_value_max=64MB,log=(enabled=),lsm=(auto_throttle=,bloom=,bloom_bit_count=16,bloom_config=,bloom_hash_count=8,bloom_oldest=0,chunk_count_limit=0,chunk_max=5GB,chunk_size=10MB,merge_max=15,merge_min=0),memory_page_max=10m,os_cache_dirty_max=0,os_cache_max=0,prefix_compression=0,prefix_compression_min=4,source=,split_deepen_min_child=0,split_deepen_per_child=0,split_pct=90,type=file,value_format=u",
"type" : "file",
"uri" : "statistics:table:collection-2-7253336746667145592",
"LSM" : {
"bloom filters in the LSM tree" : 0,
"bloom filter false positives" : 0,
"bloom filter hits" : 0,
"bloom filter misses" : 0,
"bloom filter pages evicted from cache" : 0,
"bloom filter pages read into cache" : 0,
"total size of bloom filters" : 0,
"sleep for LSM checkpoint throttle" : 0,
"chunks in the LSM tree" : 0,
"highest merge generation in the LSM tree" : 0,
"queries that could have benefited from a Bloom filter that did not exist" : 0,
"sleep for LSM merge throttle" : 0
},
"block-manager" : {
"file allocation unit size" : 4096,
"blocks allocated" : 338,
"checkpoint size" : 4096000,
"allocations requiring file extension" : 338,
"blocks freed" : 0,
"file magic number" : 120897,
"file major version number" : 1,
"minor version number" : 0,
"file bytes available for reuse" : 0,
"file size in bytes" : 4104192
},
"btree" : {
"btree checkpoint generation" : 15,
"column-store variable-size deleted values" : 0,
"column-store fixed-size leaf pages" : 0,
"column-store internal pages" : 0,
"column-store variable-size leaf pages" : 0,
"pages rewritten by compaction" : 0,
"number of key/value pairs" : 0,
"fixed-record size" : 0,
"maximum tree depth" : 3,
"maximum internal page key size" : 368,
"maximum internal page size" : 4096,
"maximum leaf page key size" : 3276,
"maximum leaf page size" : 32768,
"maximum leaf page value size" : 67108864,
"overflow pages" : 0,
"row-store internal pages" : 0,
"row-store leaf pages" : 0
},
"cache" : {
"bytes read into cache" : 9309503,
"bytes written from cache" : 10817368,
"checkpoint blocked page eviction" : 0,
"unmodified pages evicted" : 0,
"page split during eviction deepened the tree" : 0,
"modified pages evicted" : 1,
"data source pages selected for eviction unable to be evicted" : 0,
"hazard pointer blocked page eviction" : 0,
"internal pages evicted" : 0,
"pages split during eviction" : 1,
"in-memory page splits" : 1,
"overflow values cached in memory" : 0,
"pages read into cache" : 287,
"overflow pages read into cache" : 0,
"pages written from cache" : 337
},
"compression" : {
"raw compression call failed, no additional data available" : 0,
"raw compression call failed, additional data available" : 0,
"raw compression call succeeded" : 0,
"compressed pages read" : 287,
"compressed pages written" : 333,
"page written failed to compress" : 0,
"page written was too small to compress" : 4
},
"cursor" : {
"create calls" : 1,
"insert calls" : 25359,
"bulk-loaded cursor-insert calls" : 0,
"cursor-insert key and value bytes inserted" : 10697901,
"next calls" : 76085,
"prev calls" : 1,
"remove calls" : 0,
"cursor-remove key bytes removed" : 0,
"reset calls" : 25959,
"restarted searches" : 0,
"search calls" : 0,
"search near calls" : 594,
"update calls" : 0,
"cursor-update value bytes updated" : 0
},
"reconciliation" : {
"dictionary matches" : 0,
"internal page multi-block writes" : 1,
"leaf page multi-block writes" : 2,
"maximum blocks required for a page" : 47,
"internal-page overflow keys" : 0,
"leaf-page overflow keys" : 0,
"overflow values written" : 0,
"pages deleted" : 0,
"page checksum matches" : 0,
"page reconciliation calls" : 4,
"page reconciliation calls for eviction" : 1,
"leaf page key bytes discarded using prefix compression" : 0,
"internal page key bytes discarded using suffix compression" : 333
},
"session" : {
"object compaction" : 0,
"open cursor count" : 1
},
"transaction" : {
"update conflicts" : 0
}
},
"nindexes" : 4,
"totalIndexSize" : 626688,
"indexSizes" : {
"_id_" : 217088,
"borough_1_cuisine_1" : 139264,
"cuisine_1" : 131072,
"borough_1_address.zipcode_1" : 139264
},
"ok" : 1
}
由于统计信息未提供 scale 参数，因此所有大小值均位于bytes中。
具有比例的统计查询
以下操作通过将scale指定为1024将数据的大小从bytes更改为kilobytes：
db.restaurants.stats( { scale : 1024 } )
该操作返回：
{
"ns" : "guidebook.restaurants",
"count" : 25359,
"size" : 10381,
"avgObjSize" : 419,
"storageSize" : 4008,
"capped" : false,
"wiredTiger" : {
...
},
"nindexes" : 4,
"totalIndexSize" : 612,
"indexSizes" : {
"_id_" : 212,
"borough_1_cuisine_1" : 136,
"cuisine_1" : 128,
"borough_1_address.zipcode_1" : 136
},
"ok" : 1
}
具有索引详细信息的统计信息查找
以下操作将创建一个indexDetails文档，其中包含与集合中每个索引有关的信息：
db.restaurant.stats( { indexDetails : true } )
该操作返回：
{
"ns" : "guidebook.restaurants",
"count" : 25359,
"size" : 10630398,
"avgObjSize" : 419,
"storageSize" : 4104192,
"capped" : false,
"wiredTiger" : {
...
},
"nindexes" : 4,
"indexDetails" : {
"_id_" : {
"metadata" : {
"formatVersion" : 6,
"infoObj" : "{ \"v\" : 1, \"key\" : { \"_id\" : 1 }, \"name\" : \"_id_\", \"ns\" : \"blogs.posts\" }"
},
"creationString" : "allocation_size=4KB,app_metadata=(formatVersion=6,infoObj={ \"v\" : 1, \"key\" : { \"_id\" : 1 }, \"name\" : \"_id_\", \"ns\" : \"blogs.posts\" }),block_allocation=best,block_compressor=,cache_resident=0,checksum=on,colgroups=,collator=,columns=,dictionary=0,encryption=(keyid=,name=),exclusive=0,extractor=,format=btree,huffman_key=,huffman_value=,immutable=0,internal_item_max=0,internal_key_max=0,internal_key_truncate=,internal_page_max=16k,key_format=u,key_gap=10,leaf_item_max=0,leaf_key_max=0,leaf_page_max=16k,leaf_value_max=0,log=(enabled=),lsm=(auto_throttle=,bloom=,bloom_bit_count=16,bloom_config=,bloom_hash_count=8,bloom_oldest=0,chunk_count_limit=0,chunk_max=5GB,chunk_size=10MB,merge_max=15,merge_min=0),memory_page_max=5MB,os_cache_dirty_max=0,os_cache_max=0,prefix_compression=true,prefix_compression_min=4,source=,split_deepen_min_child=0,split_deepen_per_child=0,split_pct=75,type=file,value_format=u",
"type" : "file",
"uri" : "statistics:table:index-3-7253336746667145592",
"LSM" : {
...
},
"block-manager" : {
...
},
"btree" : {
...
},
"cache" : {
...
},
"compression" : {
...
},
"cursor" : {
...
},
"reconciliation" : {
...
},
"session" : {
...
},
"transaction" : {
...
}
},
"borough_1_cuisine_1" : {
"metadata" : {
"formatVersion" : 6,
"infoObj" : "{ \"v\" : 1, \"key\" : { \"borough\" : 1, \"cuisine\" : 1 }, \"name\" : \"borough_1_cuisine_1\", \"ns\" : \"blogs.posts\" }"
},
"creationString" : "allocation_size=4KB,app_metadata=(formatVersion=6,infoObj={ \"v\" : 1, \"key\" : { \"borough\" : 1, \"cuisine\" : 1 }, \"name\" : \"borough_1_cuisine_1\", \"ns\" : \"blogs.posts\" }),block_allocation=best,block_compressor=,cache_resident=0,checksum=on,colgroups=,collator=,columns=,dictionary=0,encryption=(keyid=,name=),exclusive=0,extractor=,format=btree,huffman_key=,huffman_value=,immutable=0,internal_item_max=0,internal_key_max=0,internal_key_truncate=,internal_page_max=16k,key_format=u,key_gap=10,leaf_item_max=0,leaf_key_max=0,leaf_page_max=16k,leaf_value_max=0,log=(enabled=),lsm=(auto_throttle=,bloom=,bloom_bit_count=16,bloom_config=,bloom_hash_count=8,bloom_oldest=0,chunk_count_limit=0,chunk_max=5GB,chunk_size=10MB,merge_max=15,merge_min=0),memory_page_max=5MB,os_cache_dirty_max=0,os_cache_max=0,prefix_compression=true,prefix_compression_min=4,source=,split_deepen_min_child=0,split_deepen_per_child=0,split_pct=75,type=file,value_format=u",
"type" : "file",
"uri" : "statistics:table:index-4-7253336746667145592",
"LSM" : {
...
},
"block-manager" : {
...
},
"btree" : {
...
},
"cache" : {
...
},
"compression" : {
...
},
"cursor" : {
...
},
"reconciliation" : {
...
},
"session" : {
"object compaction" : 0,
"open cursor count" : 0
},
"transaction" : {
"update conflicts" : 0
}
},
"cuisine_1" : {
"metadata" : {
"formatVersion" : 6,
"infoObj" : "{ \"v\" : 1, \"key\" : { \"cuisine\" : 1 }, \"name\" : \"cuisine_1\", \"ns\" : \"blogs.posts\" }"
},
"creationString" : "allocation_size=4KB,app_metadata=(formatVersion=6,infoObj={ \"v\" : 1, \"key\" : { \"cuisine\" : 1 }, \"name\" : \"cuisine_1\", \"ns\" : \"blogs.posts\" }),block_allocation=best,block_compressor=,cache_resident=0,checksum=on,colgroups=,collator=,columns=,dictionary=0,encryption=(keyid=,name=),exclusive=0,extractor=,format=btree,huffman_key=,huffman_value=,immutable=0,internal_item_max=0,internal_key_max=0,internal_key_truncate=,internal_page_max=16k,key_format=u,key_gap=10,leaf_item_max=0,leaf_key_max=0,leaf_page_max=16k,leaf_value_max=0,log=(enabled=),lsm=(auto_throttle=,bloom=,bloom_bit_count=16,bloom_config=,bloom_hash_count=8,bloom_oldest=0,chunk_count_limit=0,chunk_max=5GB,chunk_size=10MB,merge_max=15,merge_min=0),memory_page_max=5MB,os_cache_dirty_max=0,os_cache_max=0,prefix_compression=true,prefix_compression_min=4,source=,split_deepen_min_child=0,split_deepen_per_child=0,split_pct=75,type=file,value_format=u",
"type" : "file",
"uri" : "statistics:table:index-5-7253336746667145592",
"LSM" : {
...
},
"block-manager" : {
...
},
"btree" : {
...
},
"cache" : {
...
},
"compression" : {
...
},
"cursor" : {
...
},
"reconciliation" : {
...
},
"session" : {
...
},
"transaction" : {
...
}
},
"borough_1_address.zipcode_1" : {
"metadata" : {
"formatVersion" : 6,
"infoObj" : "{ \"v\" : 1, \"key\" : { \"borough\" : 1, \"address.zipcode\" : 1 }, \"name\" : \"borough_1_address.zipcode_1\", \"ns\" : \"blogs.posts\" }"
},
"creationString" : "allocation_size=4KB,app_metadata=(formatVersion=6,infoObj={ \"v\" : 1, \"key\" : { \"borough\" : 1, \"address.zipcode\" : 1 }, \"name\" : \"borough_1_address.zipcode_1\", \"ns\" : \"blogs.posts\" }),block_allocation=best,block_compressor=,cache_resident=0,checksum=on,colgroups=,collator=,columns=,dictionary=0,encryption=(keyid=,name=),exclusive=0,extractor=,format=btree,huffman_key=,huffman_value=,immutable=0,internal_item_max=0,internal_key_max=0,internal_key_truncate=,internal_page_max=16k,key_format=u,key_gap=10,leaf_item_max=0,leaf_key_max=0,leaf_page_max=16k,leaf_value_max=0,log=(enabled=),lsm=(auto_throttle=,bloom=,bloom_bit_count=16,bloom_config=,bloom_hash_count=8,bloom_oldest=0,chunk_count_limit=0,chunk_max=5GB,chunk_size=10MB,merge_max=15,merge_min=0),memory_page_max=5MB,os_cache_dirty_max=0,os_cache_max=0,prefix_compression=true,prefix_compression_min=4,source=,split_deepen_min_child=0,split_deepen_per_child=0,split_pct=75,type=file,value_format=u",
"type" : "file",
"uri" : "statistics:table:index-6-7253336746667145592",
"LSM" : {
...
},
"block-manager" : {
...
},
"btree" : {
...
},
"cache" : {
...
},
"compression" : {
...
},
"cursor" : {
...
},
"reconciliation" : {
...
},
"session" : {
...
},
"transaction" : {
...
}
}
},
"totalIndexSize" : 626688,
"indexSizes" : {
"_id_" : 217088,
"borough_1_cuisine_1" : 139264,
"cuisine_1" : 131072,
"borough_1_address.zipcode_1" : 139264
},
"ok" : 1
}
具有筛选的索引详细信息的统计信息查找
要过滤indexDetails字段中的索引，可以使用indexDetailsKey选项指定索引键，也可以使用indexDetailsName指定索引名称。要发现集合的索引键和名称，请使用db.collection.getIndexes()。
给定以下索引：
{
"ns" : "guidebook.restaurants",
"v" : 1,
"key" : {
"borough" : 1,
"cuisine" : 1
},
"name" : "borough_1_cuisine_1"
}
以下操作将indexDetails文档过滤为indexDetailsKey文档定义的单个索引。
db.restaurants.stats(
{
'indexDetails' : true,
'indexDetailsKey' :
{
'borough' : 1,
'cuisine' : 1
}
}
)
以下操作将indexDetails文档过滤为indexDetailsName文档定义的单个索引。
db.restaurants.stats(
{
'indexDetails' : true,
'indexDetailsName' : 'borough_1_cuisine_1'
}
)
这两个操作将返回相同的输出：
{
"ns" : "blogs.restaurants",
"count" : 25359,
"size" : 10630398,
"avgObjSize" : 419,
"storageSize" : 4104192,
"capped" : false,
"wiredTiger" : {
...
},
"nindexes" : 4,
"indexDetails" : {
"borough_1_cuisine_1" : {
"metadata" : {
"formatVersion" : 6,
"infoObj" : "{ \"v\" : 1, \"key\" : { \"borough\" : 1, \"cuisine\" : 1 }, \"name\" : \"borough_1_cuisine_1\", \"ns\" : \"blogs.posts\" }"
},
"creationString" : "allocation_size=4KB,app_metadata=(formatVersion=6,infoObj={ \"v\" : 1, \"key\" : { \"borough\" : 1, \"cuisine\" : 1 }, \"name\" : \"borough_1_cuisine_1\", \"ns\" : \"blogs.posts\" }),block_allocation=best,block_compressor=,cache_resident=0,checksum=on,colgroups=,collator=,columns=,dictionary=0,encryption=(keyid=,name=),exclusive=0,extractor=,format=btree,huffman_key=,huffman_value=,immutable=0,internal_item_max=0,internal_key_max=0,internal_key_truncate=,internal_page_max=16k,key_format=u,key_gap=10,leaf_item_max=0,leaf_key_max=0,leaf_page_max=16k,leaf_value_max=0,log=(enabled=),lsm=(auto_throttle=,bloom=,bloom_bit_count=16,bloom_config=,bloom_hash_count=8,bloom_oldest=0,chunk_count_limit=0,chunk_max=5GB,chunk_size=10MB,merge_max=15,merge_min=0),memory_page_max=5MB,os_cache_dirty_max=0,os_cache_max=0,prefix_compression=true,prefix_compression_min=4,source=,split_deepen_min_child=0,split_deepen_per_child=0,split_pct=75,type=file,value_format=u",
"type" : "file",
"uri" : "statistics:table:index-4-7253336746667145592",
"LSM" : {
...
},
"block-manager" : {
...
},
"btree" : {
...
},
"cache" : {
...
},
"compression" : {
...
},
"cursor" : {
...
},
"reconciliation" : {
...
},
"session" : {
...
},
"transaction" : {
...
}
}
},
"totalIndexSize" : 626688,
"indexSizes" : {
"_id_" : 217088,
"borough_1_cuisine_1" : 139264,
"cuisine_1" : 131072,
"borough_1_address.zipcode_1" : 139264
},
"ok" : 1
}
有关输出的说明，请参见output details。
See also