On Thu, Aug 31, 2017 at 12:16:43AM -0400, Peter Eisentraut wrote:
> In previous discussions, it has often been a source of confusion whether
> these generated columns are supposed to be computed on insert/update and
> stored, or computed when read. The SQL standard is not explicit, but
> appears to lean toward stored. DB2 stores. Oracle computes on read.
Question: How would one know the difference between storing computed
columns vs. computing them on read?
Answer?: Performance. If the computation is slow, then you'll really
notice on read.
Nico
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