Hi, Sachin! On Apr 18, Sachin Setia wrote:
Hi Actually I was thinking about how to implement blob as a foreign key.Foreign has to be unique which we can already implement. To make it foreign key we can either store unique hash or the whole blob column. But I am not sure much people want to copy so long blob data in reference table.
Agree :)
Second option would be use blob hash as a reference key. But user can not directly us hash as a reference key because that is hidden. What I was thinking of a clear to programmer way of using blob hash. Suppose user can directly create blob hash column ,use that column as a primary key or foreign key.Like create table t1(abc blob , blob hash(abc))//this will just create blob hash column create table t1(abc blob,unique(blob hash(abc))) // this will create unique blob hash column and similar for primary key and foreign key user can enter hash value if they have some good algorithm or if they do not give any value we will automatically create and store hash. What do you think? sir.
Mixed feelings. First, I wrote in an earlier email about using virtual columns for that. In this line of thoughts, a user-specified hash function is absolutely possible and logical. On the other hand, I don't see why anyone would need that - a hash is not guaranteed to be unique, no matter what algorithm one uses. And, as I wrote in an earlier email, I don't think that primary/foreign keys on blobs is a feature worth spending time on. Regards, Sergei Chief Architect MariaDB and security@mariadb.org