With an Etag (or Entity Tag) it is possible to check with the server if a resource has changed the last time it is received. The server sends an Etag in the headers of the request when a resource is received. A md5 sum of the content is a good candidate for a Etag because it changes when the content changes. It could be useful when the resource is not static but it will not change very often. The controller in a web application can perform the ETag comparison and decide when to send a the resource or a not modified. Continue reading Using ETags
This short MongoDB introduction assumes that you have a running MongoDB instance on your computer and have all command line tools installed.
When the shell command has been started the first thing you want to know is which databases are available. To do this you run the command
> show dbs admin local crm