Hi hackers,
A colleague of mine wanted to use a ScanKey with SK_SEARCHNULL flag
for a heap-only scan (besides other ScanKeys) and discovered that the
result differs from what he would expect. Turned out that this is
currently not supported as it is explicitly stated in skey.h.
Although several wo
Hi,
On 2023-02-13 17:59:13 +0300, Aleksander Alekseev wrote:
> @@ -36,20 +36,36 @@ HeapKeyTest(HeapTuple tuple, TupleDesc tupdesc, int
> nkeys, ScanKey keys)
> boolisnull;
> Datum test;
>
> - if (cur_key->sk_flags & SK_ISNULL)
> -
Hi Andres,
> Shouldn't need to extract the column if we just want to know if it's NULL (see
> heap_attisnull()). Afaics the value isn't accessed after this.
Many thanks. Fixed.
--
Best regards,
Aleksander Alekseev
v2-0001-Support-SK_SEARCHNULL-SK_SEARCHNOTNULL-for-heap-o.patch
Description: Bi
On 14/02/2023 11:10, Aleksander Alekseev wrote:
Hi Andres,
Shouldn't need to extract the column if we just want to know if it's NULL (see
heap_attisnull()). Afaics the value isn't accessed after this.
Many thanks. Fixed.
I'm confused, what exactly is the benefit of this? What extension
per
Hi,
> I'm confused, what exactly is the benefit of this? What extension
> performs a direct table scan bypassing the executor, searching for NULLs
> or not-NULLs?
Basically any extension that accesses the tables without SPI in order
to avoid parsing and planning overhead for relatively simple cas
On 22/02/2023 15:03, Aleksander Alekseev wrote:
Additionally, practice shows that for an extension author it's very
easy to miss a comment in skey.h:
"""
* SK_SEARCHARRAY, SK_SEARCHNULL and SK_SEARCHNOTNULL are supported only
* for index scans, not heap scans;
"""
... which results in many
On 7/19/23 16:44, Jacob Champion wrote:
> This patch pushes down any
> forced-null and not-null Vars as ScanKeys. It doesn't remove the
> redundant quals after turning them into ScanKeys, so it's needlessly
> inefficient, but there's still a decent speedup for some of the basic
> benchmarks in 0003
On Mon, Feb 27, 2023 at 12:24 AM Heikki Linnakangas wrote:
> On 22/02/2023 15:03, Aleksander Alekseev wrote:
> > If memory serves I noticed that WHERE ... IS NULL queries don't even
> > hit HeapKeyTest() and I was curious where the check for NULLs is
> > actually made. As I understand, SeqNext() i
