We have a web application with single site collection and one document library, mainly used for uploading supporting business documents (.pdf, .doc and .xml). Current content DB size is 160 GB with daily increase of 2 GB reaching closer to set 200 GB limitation set by Microsoft best practices. I read on blogs if the site is solely used for Records Center content DB size can go up to 1 TB.
Does 1 TB rule apply to our site collection? Anything we have to know or do to avoid any disaster?
The main reason Backup & Recovery (Requirements for backup and restore may not be met by the native SharePoint Server 2013 backup for content databases larger than 200 GB) of site collection, Monitoring & managing the Db.
You can go upto 4TB Content database size (all usage scenarios), as you have only one site collection in that db. IF you meet the below requirement then you all set for 4TB size.
Check this: http://technet.microsoft.com/en-us/library/cc262787(v=office.15).aspx#ContentDB
As Alternative:
You should think about splitting your site collection into multiple site collections and provision them into own Content Database. In this way your DB size will be under 200 GB.
There is a reason why Document Center, Records Center have a different threshold (an interesting could be found here). Because many functionalities are disabled for those particular Templates, which makes it a lot more to be used to "non-living" content. Of course, the issues mentioned by Waqas are absolutely valid, and design should prime - and it's all about the SLAs you need to support.
