Mysql 5.1: if we want to use very large blobs, apparently we need very large packets, configured identically on both ends. How large can we go before something explodes?
That page you linked to describes exactly what a packet is. It is:
So, if your packet size is set to 16Mb, then you won't be able to return a row larger than 16Mb in size. If you have the potential to be storing a 500Mb BLOB then you will need to increase your packet size to > 500Mb to accomodate this.
MySQL cannot return a single row larger than 1Gb, so I guess your maximum blob size is