MongoDB : Collection and statistics Information

------get all the database collection count at once:---------

db.getCollectionNames().map(function(colName){return {"columnName":colName,"count":db.getCollection(colName).count()}});

----The following script prints the statistics for each database:----------

db._adminCommand("listDatabases").databases.forEach(function (d) {

   mdb = db.getSiblingDB(d.name);

   printjson(mdb.stats());

})

-----The following script prints the statistics for each collection in each database:-----

db._adminCommand("listDatabases").databases.forEach(function (d) {

   mdb = db.getSiblingDB(d.name);

   mdb.getCollectionNames().forEach(function(c) {

      s = mdb[c].stats();

      printjson(s);

   })

})

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