Re: Help on indexing timestamps

On Fri, 7 Mar 2003 13:01:16 -0200 (GMT+2)
Achilleus Mantzios <achill@matrix.gatewaynet.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..1579.89rows=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@matrix.gatewaynet.com
>         mantzios@softlab.ece.ntua.gr
> 
> 
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