Re: postgres_fdw: Handle boolean comparison predicates

The following review has been posted through the commitfest application:
make installcheck-world:  tested, passed
Implements feature:       tested, passed
Spec compliant:           tested, passed
Documentation:            not tested

Hello

I tried to apply the patch to master branch and got a couple of errors, so I think the patch needs a rebase. 

I also agree with Ashutosh that the "IS NOT TRUE" case can be simplified to just "IS FALSE". it's simpler to
understand.

based on this, I think we should restructure the switch-case statement in deparseBooleanTest because some of the cases
inthere evaluate to the same result but handles differently. 
 

For example, "IS TRUE" and "IS NOT FALSE" both evaluate to true, so can be handled in the same way

something like:
switch (node->booltesttype)
{
    case IS_TRUE:
    case IS_NOT_FALSE:
        appendStringInfoChar(buf, '(');
        deparseExpr(node->arg, context);
        appendStringInfoString(buf, ")");
        break;
    case IS_FALSE:
    case IS_NOT_TRUE:
        appendStringInfoChar(buf, '(');
        deparseExpr(node->arg, context);
        appendStringInfoString(buf, " IS FALSE)");
        break;
    case IS_UNKNOWN:
        appendStringInfoChar(buf, '(');
        deparseExpr(node->arg, context);
        appendStringInfoString(buf, " IS NULL)");
        break;
    case IS_NOT_UNKNOWN:
        appendStringInfoChar(buf, '(');
        deparseExpr(node->arg, context);
        appendStringInfoString(buf, " IS NOT NULL)");
        break;
}

just a thought
thanks!

-------------------------------
Cary Huang
HighGo Software Canada
www.highgo.ca