Thread: calculating elapsed times between timestamps
(posted on novice too, no idea what difference is between lists) I have been trying to do this and have been unsuccessful so far. I have a table: perf: timestamp = timestamp with time zone timeelapsed = numeric bobble = text timeelapsed records are the time elapsed metric in seconds. e.g. 0.350058078765869 Typical scenario is that I'll have multiple entries where timeelapsed is greater than some value and will be greater than that value for some time interval. I want to find the length of those intervals. select timestamp, timeelapsed, bobble from perf where bobble like "pokerflat" and timeelapsed > 0.4; The records returned by that query will have an oldest and newest timestamp for which I would like to calculate the interval. I found lots of examples of doing arithmetic on timestamps but I never saw any extracting data from a table. All the examples I found were using now() or current_date + 3 or the like. Do aggregate function work on time data?
rhubbell wrote: > (posted on novice too, no idea what difference is between lists) > > I have been trying to do this and have been unsuccessful so far. > > I have a table: > > perf: > timestamp = timestamp with time zone > timeelapsed = numeric > bobble = text > > timeelapsed records are the time elapsed metric in seconds. > > e.g. 0.350058078765869 > > Typical scenario is that I'll have multiple entries where timeelapsed > is greater than some value and will be greater than that value for > some time interval. > > > I want to find the length of those intervals. > > select timestamp, timeelapsed, bobble from perf where bobble like "pokerflat" > and timeelapsed > 0.4; > > The records returned by that query will have an oldest and newest timestamp for > which I would like to calculate the interval. > I'm not real clear on what you are asking here with oldest and newest timestamps and getting the interval, please clarify > I found lots of examples of doing arithmetic on timestamps but I never saw > any extracting data from a table. All the examples I found were using now() > or current_date + 3 or the like. > Just substitute current_date or now() appears in the examples with the column name > Do aggregate function work on time data? > For date time function go here http://www.postgresql.org/docs/8.3/static/functions-datetime.html
On Mon, 02 Feb 2009 21:36:54 -0500 justin <justin@emproshunts.com> wrote: > rhubbell wrote: > > (posted on novice too, no idea what difference is between lists) > > > > I have been trying to do this and have been unsuccessful so far. > > > > I have a table: > > > > perf: > > timestamp = timestamp with time zone > > timeelapsed = numeric > > bobble = text > > > > timeelapsed records are the time elapsed metric in seconds. > > > > e.g. 0.350058078765869 > > > > Typical scenario is that I'll have multiple entries where timeelapsed > > is greater than some value and will be greater than that value for > > some time interval. > > > > > > I want to find the length of those intervals. > > > > select timestamp, timeelapsed, bobble from perf where bobble like "pokerflat" > > and timeelapsed > 0.4; > > > > The records returned by that query will have an oldest and newest timestamp for > > which I would like to calculate the interval. > > > I'm not real clear on what you are asking here with oldest and newest > timestamps and getting the interval, please clarify time a = etime == .211 time b = etime == .312 time c = etime == .311 time d = etime == .301 time e = etime == .201 select returned all etime < .29 I want to know "time d" - "time b" "time d" == newest "time b" == oldest > > I found lots of examples of doing arithmetic on timestamps but I never saw > > any extracting data from a table. All the examples I found were using now() > > or current_date + 3 or the like. > > > Just substitute current_date or now() appears in the examples with the > column name Ok, will try that. > > Do aggregate function work on time data? > > > > For date time function go here > http://www.postgresql.org/docs/8.3/static/functions-datetime.html >
On Mon, 2 Feb 2009 18:53:07 -0800 rhubbell <Rhubbell@iHubbell.com> wrote: > On Mon, 02 Feb 2009 21:36:54 -0500 > justin <justin@emproshunts.com> wrote: > > > rhubbell wrote: > > > (posted on novice too, no idea what difference is between lists) > > > > > > I have been trying to do this and have been unsuccessful so far. > > > > > > I have a table: > > > > > > perf: > > > timestamp = timestamp with time zone > > > timeelapsed = numeric > > > bobble = text > > > > > > timeelapsed records are the time elapsed metric in seconds. > > > > > > e.g. 0.350058078765869 > > > > > > Typical scenario is that I'll have multiple entries where timeelapsed > > > is greater than some value and will be greater than that value for > > > some time interval. > > > > > > > > > I want to find the length of those intervals. > > > > > > select timestamp, timeelapsed, bobble from perf where bobble like "pokerflat" > > > and timeelapsed > 0.4; > > > > > > The records returned by that query will have an oldest and newest timestamp for > > > which I would like to calculate the interval. > > > > > I'm not real clear on what you are asking here with oldest and newest > > timestamps and getting the interval, please clarify > > time a = etime == .211 > time b = etime == .312 > time c = etime == .311 > time d = etime == .301 > time e = etime == .201 > > select returned all etime < .29 Uh, meant etime > .29 > > I want to know "time d" - "time b" > "time d" == newest > "time b" == oldest > > > > > I found lots of examples of doing arithmetic on timestamps but I never saw > > > any extracting data from a table. All the examples I found were using now() > > > or current_date + 3 or the like. > > > > > Just substitute current_date or now() appears in the examples with the > > column name > > Ok, will try that. > > > > Do aggregate function work on time data? > > > > > > > For date time function go here > > http://www.postgresql.org/docs/8.3/static/functions-datetime.html > > > > -- > Sent via pgsql-general mailing list (pgsql-general@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general
On Mon, Feb 2, 2009 at 5:54 PM, rhubbell <Rhubbell@ihubbell.com> wrote:
>
> I want to find the length of those intervals.
>
> select timestamp, timeelapsed, bobble from perf where bobble like "pokerflat"
> and timeelapsed > 0.4;
>
> The records returned by that query will have an oldest and newest timestamp for
> which I would like to calculate the interval.
The easiest way is to just subtract one timestamp from another... If
you want the difference in seconds, then use extract
select '2009-01-31 12:34'::timestamp - '2009-01-12 15:34'::timestamp;
?column?
------------------
18 days 21:00:00
select extract(epoch from '2009-01-31 12:34'::timestamp - '2009-01-12
15:34'::timestamp);
date_part
-----------
1630800
Does that get you closer to an answer?
On Tue, 3 Feb 2009 02:08:54 -0700 Scott Marlowe <scott.marlowe@gmail.com> wrote: > On Mon, Feb 2, 2009 at 5:54 PM, rhubbell <Rhubbell@ihubbell.com> wrote: > > > > I want to find the length of those intervals. > > > > select timestamp, timeelapsed, bobble from perf where bobble like "pokerflat" > > and timeelapsed > 0.4; > > > > The records returned by that query will have an oldest and newest timestamp for > > which I would like to calculate the interval. > > The easiest way is to just subtract one timestamp from another... If > you want the difference in seconds, then use extract > > select '2009-01-31 12:34'::timestamp - '2009-01-12 15:34'::timestamp; > ?column? > ------------------ > 18 days 21:00:00 > select extract(epoch from '2009-01-31 12:34'::timestamp - '2009-01-12 > 15:34'::timestamp); > date_part > ----------- > 1630800 > > Does that get you closer to an answer? Yes, thanks. I actually solved in a different way but this helps toward understanding sql a little better. I think the s in sql is crippling. I feel like I've traveled back in time whenever I use sql. > > -- > Sent via pgsql-general mailing list (pgsql-general@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general