On 21/10/2020 20:13, Andrey Borodin wrote:
7 окт. 2020 г., в 17:38, Heikki Linnakangas <hlinn...@iki.fi> написал(а):
On 07/10/2020 15:27, Andrey Borodin wrote:
Here's draft patch with implementation of sortsupport for ints and floats.
+static int
+gbt_int4_cmp(Datum a, Datum b, SortSupport ssup)
+{
+ int32KEY *ia = (int32KEY *) DatumGetPointer(a);
+ int32KEY *ib = (int32KEY *) DatumGetPointer(b);
+
+ if (ia->lower == ib->lower)
+ {
+ if (ia->upper == ib->upper)
+ return 0;
+
+ return (ia->upper > ib->upper) ? 1 : -1;
+ }
+
+ return (ia->lower > ib->lower) ? 1 : -1;
+}
We're only dealing with leaf items during index build, so the 'upper' and
'lower' should always be equal here, right? Maybe add a comment and an
assertion on that.
(It's pretty sad that the on-disk representation is identical for leaf and
internal items, because that wastes a lot of disk space, but that's way out of
scope for this patch.)
Thanks, I've added assert() where is was easy to test equalty.
PFA patch with all types.
gbt_ts_cmp(), gbt_time_cmp_sort() and gbt_date_cmp_sort() still have the
above issue, they still compare "upper" for no good reason.
+static Datum
+gbt_bit_abbrev_convert(Datum original, SortSupport ssup)
+{
+ return (Datum) 0;
+}
+
+static int
+gbt_bit_cmp_abbrev(Datum z1, Datum z2, SortSupport ssup)
+{
+ return 0;
+}
If an abbreviated key is not useful, just don't define abbrev functions
and don't set SortSupport->abbrev_converter in the first place.
static bool
gbt_inet_abbrev_abort(int memtupcount, SortSupport ssup)
{
#if SIZEOF_DATUM == 8
return false;
#else
return true;
#endif
}
Better to not set the 'abbrev_converter' function in the first place. Or
would it be better to cast the float8 to float4 if SIZEOF_DATUM == 4?
I had a plan to implement and test one type each day. I did not quite
understood how rich our type system is.
:-)
- Heikki
