Posts Tagged WiredTiger

MongoDB 3.x – How to get more details about a collection in MongoDB

MongoDB 3.x – How to get more details about a collection in MongoDB

In MongoDB shell

mongo> db.collection.stats()

{{ "ns" : "db.collection", 
"count" : 1474168, 
"size" : 1628955640, 
"avgObjSize" : 1105, 
"storageSize" : 62074880, 
"capped" : false, 
"wiredTiger" : 
     { "metadata" : { "formatVersion" : 1 }, 
     "creationString" : "access_pattern_hint=none,
          allocation_size=4KB,app_metadata=(formatVersion=1),
          block_allocation=best,block_compressor=zlib,cache_resident=false,
          checksum=on,colgroups=,collator=,columns=,dictionary=0,encryption=(keyid=,name=),
          exclusive=false,extractor=,format=btree,huffman_key=,huffman_value=,
          ignore_in_memory_cache_size=false,immutable=false,internal_item_max=0,
          internal_key_max=0,internal_key_truncate=true,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=true),lsm=(auto_throttle=true,bloom=true,
          bloom_bit_count=16,bloom_config=,bloom_hash_count=8,bloom_oldest=false,
          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=false,
          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/0-8813564358223606299", 
"nindexes" : 3, 
"totalIndexSize" : 83034112, 
"indexSizes" : { "_id_" : 72835072, "st_1_ih_1_vt_1_ua_1" : 5107712, "ea_1" : 5091328 }, 
"ok" : 1}

From the above, we can gather a few important things (highlighted in bold):

  1. There are 1474168 documents in the collections
  2. On disk, ignoring any filesystem compression, it is about 62074880 bytes
  3. It is using zlib compression
  4. On disk, the datafile will be $dbPath/collection/0-8813564358223606299.wt
  5. There are 3 indexes on this collection

Hope this helps!

Regards,
Wei Shan

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