According to relational theory, relations are immutable sets of tuples. The way you “change” a relation is by assigning a new relation to the name, e.g.:
R1 <- R1 union R2
Is the relational algebra way of “inserting” R2 into R1. Of course, most RDBMS’s (and the SQL family of languages) are only reasonably faithful implementations of relational theory under some practical constraints.
But those differences re important, and I think the authors are proposing a new relational model (though I don’t think this is a totally new idea; I’m not a database researcher). One that incorporates time and history of a relation as first-class citizens of the theory, that allows sql to operate natively on both traditional relational-theoretic relations and streams of data. Pretty cool! Can anyone who knows more than me comment on how this relates to Kafka tables, which seems to me a similar concept?
R1 <- R1 union R2
Is the relational algebra way of “inserting” R2 into R1. Of course, most RDBMS’s (and the SQL family of languages) are only reasonably faithful implementations of relational theory under some practical constraints.
But those differences re important, and I think the authors are proposing a new relational model (though I don’t think this is a totally new idea; I’m not a database researcher). One that incorporates time and history of a relation as first-class citizens of the theory, that allows sql to operate natively on both traditional relational-theoretic relations and streams of data. Pretty cool! Can anyone who knows more than me comment on how this relates to Kafka tables, which seems to me a similar concept?