| From: | Peter Eisentraut <peter(dot)eisentraut(at)2ndquadrant(dot)com> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | David Steele <david(at)pgmasters(dot)net>, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>, Thomas Munro <thomas(dot)munro(at)gmail(dot)com>, Petr Fedorov <petr(dot)fedorov(at)phystech(dot)edu>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Since '2001-09-09 01:46:40'::timestamp microseconds are lost when extracting epoch |
| Date: | 2021-03-22 20:58:20 |
| Message-ID: | fcb54768-3d0a-d742-4bdb-4f2cef43d094@2ndquadrant.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-bugs pgsql-hackers |
On 19.03.21 21:06, Tom Lane wrote:
> I guess the immediate question is how much of a performance gap there
> is now between the float and numeric implementations.
Attached are my test script and the full output.
To summarize, for cases that don't do any interesting computation and
where the overhead is only the data type passing, the difference is like
this:
-- old
select date_part('microseconds', current_timestamp + generate_series(0,
10000000) * interval '1 second') \g /dev/null
Time: 2760.966 ms (00:02.761)
-- new
select extract(microseconds from current_timestamp + generate_series(0,
10000000) * interval '1 second') \g /dev/null
Time: 3178.477 ms (00:03.178)
| Attachment | Content-Type | Size |
|---|---|---|
| output.txt | text/plain | 21.7 KB |
| test.sql | text/plain | 16.9 KB |
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Scott | 2021-03-22 23:59:48 | Multiple Values Inserts for Generated Columns Erroring Out |
| Previous Message | Tom Lane | 2021-03-22 18:22:48 | Re: BUG #16938: Duplicate records with same Primary Key |
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Thomas Munro | 2021-03-22 21:07:07 | Re: proposal - psql - use pager for \watch command |
| Previous Message | Robert Haas | 2021-03-22 20:57:18 | Re: [HACKERS] Custom compression methods |