> Is there any possibility of overlapping rows between the parts of the
> union? If not, I'd suggest union all, since that might get rid of the top
> level unique and sort steps (probably not a huge gain, but might help).
Hi,
thanx for the response, there is a little possibility of overlapping
On Fri, 27 Jul 2001, Robert Vojta wrote:
> netacc=> EXPLAIN (SELECT SUM(counterfrom) AS from, SUM(counterto) AS to,
> floor((985098900 - date_part('epoch', counterstamp)) / 300) AS sequence
> FROM counters WHERE line='absolonll' AND date_part('epoch', counterstamp)
> > 984978900 GROUP BY sequence
> The index is only used for the line= part of the where clause
> with your query. With many rows the "line=" is not selective enough
> to justify the index.
I tried move only needed data into new table and change query into ...
netacc=> EXPLAIN SELECT counterfrom AS from, counterto AS to,
fl
> The index is only used for the line= part of the where clause
> with your query. With many rows the "line=" is not selective enough
> to justify the index.
Hi,
I tried you suggestion about 'AND counterstamp > '2001-07-26 00:00:00.0' and
it works and index is used :) But, whole query run for
> I would guess the problem is the restriction on counterstamp, because
> written like that, it probably can't use the index.
>
> try something where you avoid the use of the date_part function e.g.:
> AND counterstamp > '2001-07-26 00:00:00.0'
I will try it, but it use the index when t
> netacc=> EXPLAIN (SELECT SUM(counterfrom) AS from,
> SUM(counterto) AS to,
> floor((985098900 - date_part('epoch', counterstamp)) / 300)
> AS sequence
> FROM counters WHERE line='absolonll' AND date_part('epoch',
> ) counterstamp > 984978900 GROUP BY sequence, line) ...
I would guess the pr
Hi,
I'm fighting with problem with indexes. I read documentation about
performance tips, about internal logic functions which are making decision
if to use or not use indexes, etc. and I'm still failed. I'm not SQL
guru and I don't know what to do now. My tables and indexes looks like
...
CREAT
