Let $\text{R}_1, \text{R}_2, \ldots,\text{ }R_n$ be a decomposition of schema $\text{U}$. Let $u(\text{U})$ be a relation, and let $r_i=\Pi_{\text{R}_i}(u)$
Which of the following is true?
- $u \subseteq r_1 \bowtie r_2 \bowtie r_3 \bowtie r_4 \bowtie \ldots r_n$
- $u \supseteq r_1 \bowtie r_2 \bowtie r_3 \bowtie r_4 \bowtie \ldots r_n$
- $u=r_1 \bowtie r_2 \bowtie r_3 \bowtie r_4 \bowtie . . r_n$
- None of the above
