type coercion after failing to find an exact match in pg_proc, but before
considering interpretations that involve a function call with one or
more argument type coercions. This avoids surprises wherein what looks
like a type coercion is interpreted as coercing to some third type and
then to the destination type, as in Dave Blasby's bug report of 3-Oct-01.
See subsequent discussion in pghackers.
/*
* parse function
* This code is confusing because the database can accept
* relation.column, column.function, or relation.column.function.
* In these cases, funcname is the last parameter, and fargs are
* the rest.
*
* It can also be called as func(col) or func(col,col).
* In this case, Funcname is the part before parens, and fargs
* are the part in parens.
*
*/
Node *
ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
bool agg_star, bool agg_distinct,
int precedence)
from Param nodes, per discussion a few days ago on pghackers. Add new
expression node type FieldSelect that implements the functionality where
it's actually needed. Clean up some other unused fields in Func nodes
as well.
NOTE: initdb forced due to change in stored expression trees for rules.
actually a type-coercion problem. If you have a function defined on
class A, and class B inherits from A, then the function ought to work
on class B as well --- but coerce_type didn't know that. Now it does.
yet, but at least we can give a better error message:
regression=> select count(distinct f1) from int4_tbl;
ERROR: aggregate(DISTINCT ...) is not implemented yet
instead of 'parser: parse error at or near distinct'.
sort order down into planner, instead of handling it only at the very top
level of the planner. This fixes many things. An explicit sort is now
avoided if there is a cheaper alternative (typically an indexscan) not
only for ORDER BY, but also for the internal sort of GROUP BY. It works
even when there is no other reason (such as a WHERE condition) to consider
the indexscan. It works for indexes on functions. It works for indexes
on functions, backwards. It's just so cool...
CAUTION: I have changed the representation of SortClause nodes, therefore
THIS UPDATE BREAKS STORED RULES. You will need to initdb.
Tom Lane
Bruce Momjian
Thomas G. Lockhart
Marc G. Fournier