Re: Help on indexing timestamps

On Fri, 7 Mar 2003 13:01:16 -0200 (GMT+2)
Achilleus Mantzios <achill(at)matrix(dot)gatewaynet(dot)com> wrote:

> On Fri, 7 Mar 2003, Andre Schubert wrote:
>
> > Hi all,
> >
> > i have a little problem on indexing a table which contains
> > about 4 millions of traffic-data.
> > My problem is, that a want to select all data from
> > a specific month from a specific ip and this select should use the index.
> > I use the following select:
>
> Did you try to use BETWEEN ??
> E.g.
> ... and time_stamp between '2003-01-01 00:00:00'::timestamp and
> '2003-02-01 00:00:00'::timestamp
>

Yes and it works if i write the dates by hand, every new month.
But the query is executed automatically and i dont want
to write in the dates before the query is executed. Maybe the
the start and enddate should also be alculated with sql,
because i want to create a view from this statement and execute it every month.
Or did i miss something.

Regards, as

> >
> > db_nmkm3aue=# explain analyze select sum(inet_up+inet_down) from tbl_traffic where date_trunc('month',tbl_traffic.time_stamp)::timestamptz = date_trunc('month',now() - timespan('1 months')) and ip = '80.243.38.57';
> > NOTICE: QUERY PLAN:
> >
> > Aggregate (cost=116.30..116.30 rows=1 width=16) (actual time=1620.79..1620.79 rows=1 loops=1)
> > -> Index Scan using idx_ip_time_stamp on tbl_traffic (cost=0.00..116.30 rows=1 width=16) (actual time=1216.79..1579.89 rows=5232 loops=1)
> > Total runtime: 1620.94 msec
> >
> > But it takes a long time to select the traffic for all Ips.
> > Is there a way to select these data with using the index correctly ?
> >
> > Thanks in advance
> >
> > BTW: Table-schema as follows
> >
> > db_test=# \d tbl_traffic
> > Table "tbl_traffic"
> > Column | Type | Modifiers
> > ------------+--------------------------+-----------
> > time_stamp | timestamp with time zone | not null
> > ip | inet |
> > local_up | bigint | not null
> > local_down | bigint | not null
> > inet_up | bigint | not null
> > inet_down | bigint | not null
> > Indexes: idx_ip_time_stamp
> >
> > db_test=# \d idx_ip_time_stamp
> > Index "idx_ip_time_stamp"
> > Column | Type
> > ------------+--------------------------
> > ip | inet
> > time_stamp | timestamp with time zone
> >
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>
> --
> ==================================================================
> Achilleus Mantzios
> S/W Engineer
> IT dept
> Dynacom Tankers Mngmt
> Nikis 4, Glyfada
> Athens 16610
> Greece
> tel: +30-210-8981112
> fax: +30-210-8981877
> email: achill(at)matrix(dot)gatewaynet(dot)com
> mantzios(at)softlab(dot)ece(dot)ntua(dot)gr
>
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