Re: Export user visible function to make use of convert_to_scalar

"Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:

> When complaining I hadn't read the pghackers thread in which you
> suggested this, and now that I'm caught up on email I remain
> unconvinced. What do you need convert_to_scalar for in order to display
> the pg_statistic histogram? You've already got the underlying data.

Then the charting tool would have to duplicate all the same code that
convert_to_scalar has to figure out what to do with the data.

What I can generate already is a bar chart for integer data types. But I think
it would be most useful for string data types. In one of the cases I've helped
someone with before they had comment spam constituting a sizable fraction of
their database throwing off statistics and forcing a sequential scan.

It might be simplest to expose an extern definition of the C function with a
comment saying it's internal and changes are planned.

Incidentally, I wonder if it makes more sense to make this an optional btree
operator class support procedure rather than a type function.

--
Gregory Stark
EnterpriseDB http://www.enterprisedb.com