I wrote: > If you're lost about the point here, it's this: an ArrayExpr can > represent the result of an array assignment. For example, given > UPDATE foo SET a[42] = x, what is generated is an ArrayExpr > with refexpr = a, refupperindexpr = 42, refassgnexpr = x. > On execution that generates the updated array value that needs to > get stored back into the "a" column. How would you like to print > that in EXPLAIN? Same deal for FieldStore: it can represent generating > the new value of a composite column after replacing one field.
After thinking about this for awhile, the best representation I can come up with is to let the EXPLAIN output look like an UPDATE assignment. That is, from something like UPDATE foo SET arraycol[42] = x WHERE ... an EXPLAIN VERBOSE would include this in the targetlist display: Output: ... , arraycol[42] = x , ... An alternative possibility is to strip the indirection node(s) and just show "x"; but that seems to leave a good deal of information hidden, especially if the subscript expressions are complicated. Objections, better ideas? regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers