What is meant by filesize and datasize in MongoDB?

Question

I am started using MongoDB few days ago, and i have problem in understanding some database architecture. If i execute the query db.stats(); i had got filesize ,datasize,storagesize & indexsize. While i am surfing i found that the following:

Storagesize = datasize + free space allocated for collection

datasize = database size utilised by MongoDB

Here, I could not understand the representaion of filesize & datasize reprsentation. For datasize --> indexsize is also included?. Please provide a precise solution for the specified attributes and please do correct me if i mentioned anythng wrong.

Advance Thanks,

Answer 1

• dataSize : Sum of all actual data (BSON objects) used by the database, in bytes
• indexSize : Sum of all indexes used by the database, in bytes
• storageSize : dataSize plus all preallocated collection space, in bytes
• fileSize : Sum of the sizes of all files allocated for this database (e.g. test.0 + test.1 etc.), in bytes
• nsSizeMB : Size of namespace file for this database, in megabytes.
• avgObjSize : Average size of document objects in database. This value includes padding and may therefore not change when you reduce the size of documents.