Any luck on appending two table in PostgreSQL.
Below are two table with same schema that have different values. In this case EmpID is unique value.
tabelA
------------
EmpId (Int) EmpName (String)
1 Hanu
2 Alvaro
tabelB
------------
EmpId (Int) EmpName (String)
3 Michal
4 Tom
I would be looking below output after appending tableA with tableB. Is this possible in PostgreSQL?
tabelA
------------
EmpId (Int) EmpName (String)
1 Hanu
2 Alvaro
3 Michal
4 Tom
Thanks,
Hanu
On 5/30/07, Hanu Kurubar <hanu.kurubar@xxxxxxxxx> wrote:
Can you help me appending two table values into single table without performing INSERT?Note that these tables are of same schema.Is there any sql command is supported?Thanks,Hanu
On 5/29/07, Alvaro Herrera <alvherre@xxxxxxxxxxxxxxxxx > wrote:Michal Szymanski wrote:
> There is another strange thing. We have two versions of our test
> >>environment one with production DB copy and second genereated with
> >>minimal data set and it is odd that update presented above on copy of
> >>production is executing 170ms but on small DB it executing 6s !!!!
> >
> >How are you vacuuming the tables?
> >
> Using pgAdmin (DB is installed on my laptop) and I use this tool for
> vaccuminh, I do not think that vaccuming can help because I've tested on
> both database just after importing.
I think you are misunderstanding the importance of vacuuming the table.
Try this: on a different terminal from the one running the test, run a
VACUUM on the updated table with vacuum_cost_delay set to 20, on an
infinite loop. Keep this running while you do your update test. Vary
the vacuum_cost_delay and measure the average/min/max UPDATE times.
Also try putting a short sleep on the infinite VACUUM loop and see how
its length affects the UPDATE times.
One thing not clear to me is if your table is in a clean state. Before
running this test, do a TRUNCATE and import the data again. This will
get rid of any dead space that may be hurting your measurements.
--
Alvaro Herrera http://www.advogato.org/person/alvherre
"The Postgresql hackers have what I call a "NASA space shot" mentality.
Quite refreshing in a world of "weekend drag racer" developers."
(Scott Marlowe)
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With best regards,
Hanumanthappa Kurubar
Mobile: 98 801 800 65
--
With best regards,
Hanumanthappa Kurubar
Mobile: 98 801 800 65
