1. A computer program product, comprising a non-transitory computer usable medium having a computer readable program code embodied therein, the computer readable program code adapted to be executed to implement a method, the method comprising: providing a multi-tenant database system that is shared by multiple tenants, wherein content of one tenant is kept logically separate from content of other tenants; receiving content at the multi-tenant database system from one of the tenants of the multi-tenant database system for storage thereof in the multi-tenant database system, the received content being in a first format; determining whether a database of the multi-tenant database system supports the first format of the received content; in response to determining that the database supports the first format of the received content, storing the received content in the database; in response to determining that the database does not support the first format of the received content: determining whether a copy of the received content is stored in a file server of the multi-tenant database system that is separate from the database, and (i) in response to determining that the copy of the received content is not stored in the file server: storing the received content in the file server separate from the database, storing, in the database separate from the file server, a first instance of metadata referencing a location of the stored content in the file server, configuring a counter specific to the stored content to an initial value, wherein the counter is of a number of instances of metadata in the database referencing the location of the stored content in the file server, and enabling access by the tenant to the stored content in the file server via the first instance of the metadata, and (ii) in response to determining that the copy of the received content is stored in the file server: storing, in the database separate from the file server, a second instance of metadata referencing the location of the stored content in the file server, incrementing the counter specific to the stored content, and enabling access by the tenant to the stored content in the file server via the second instance of the metadata, receiving at the multi-tenant database system from the tenant a request that the stored content be converted from the first format to a second format different from the first format, in response to receiving the request, converting the stored content in the file server from the first format to the second format and converting a field of the file server storing the stored content from being configured to store content of the first format to being configured to store content of the second format, for each instance of the metadata in the database referencing the location of the stored content in the file server, setting a flag included in the metadata to indicate that a type of the stored content has been changed; wherein the multi-tenant database system limits an amount of content allowed to be stored by each tenant in the multi-tenant database system to a maximum amount, and wherein content stored in the file server by a particular tenant and referenced by multiple instances of metadata is counted once against the maximum amount allowed to be stored by the particular tenant.