Re: Optimizing nested ConvertRowtypeExpr execution

Hi,

On 2018-02-26 17:20:05 +0530, Ashutosh Bapat wrote:
> In a multi-level partitioned table, a parent whole-row reference gets
> translated into nested ConvertRowtypeExpr with child whole-row
> reference as the leaf. During the execution, the child whole-row
> reference gets translated into all all intermediate parents' whole-row
> references, ultimately represented as parent's whole-row reference.
> AFAIU, the intermediate translations are unnecessary. The leaf child
> whole-row can be directly translated into top parent's whole-row
> reference. Here's a WIP patch which does that by eliminating
> intermediate ConvertRowtypeExprs during ExecInitExprRec().

Why is this done appropriately at ExecInitExpr() time, rather than at
plan time? Seems like eval_const_expressions() would be a bit more
appropriate (being badly named aside...)?

- Andres