Re: [HACKERS] how to add seconds to a TimestampTz
Alvaro Herrera wrote: Is there a better way than going to time_t and back? I am currently using this: db-next_worker = time_t_to_timestamptz(timestamptz_to_time_t(current_time) + autovacuum_naptime); (db-next_worker is a TimestampTz, as is current_time. autovacuum_naptime is integer for a number of seconds) For the archives, I just discovered on timestamp.h this macro to help: avdb-ad_next_worker = TimestampTzPlusMilliseconds(now, naptime_secs * 1000); This is a lot simpler and faster ... -- Alvaro Herrerahttp://www.CommandPrompt.com/ PostgreSQL Replication, Consulting, Custom Development, 24x7 support ---(end of broadcast)--- TIP 5: don't forget to increase your free space map settings
Re: [HACKERS] how to add seconds to a TimestampTz
Tom Lane wrote: Alvaro Herrera [EMAIL PROTECTED] writes: Is there a better way than going to time_t and back? Isn't the standard SQL-level locution timestamptz + numeric_value * '1 second'::interval ? I'm not sure what would be the most convenient realization of this at the C level, but please stay away from time_t ... Yes, it is, but we would have to be calling interval input, interval-times-integer, then interval-plus-timestamp, each time we scheduled a worker (to calculate the time of next worker start), which sounds like too much work ... an idea would be to store the result of interval input and multiplication, and recalculate each time we got SIGHUP. But then, maybe this is premature optimization on my part. I'll write it in the natural form for now, and then we'll see if we should rewrite it; and then, maybe it's easier to write something equivalent to TimestampDifference ... -- Alvaro Herrerahttp://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc. ---(end of broadcast)--- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate
Re: [HACKERS] how to add seconds to a TimestampTz
On Mar 15, 2007, at 5:58 AM, Tom Lane wrote: ? I'm not sure what would be the most convenient realization of this at the C level, but please stay away from time_t ... what's wrong with time_t ? Does postgres has some sort of time API, that can be used instead? -- Grzegorz Jaskiewicz C/C++ freelance for hire ---(end of broadcast)--- TIP 2: Don't 'kill -9' the postmaster
Re: [HACKERS] how to add seconds to a TimestampTz
If you read the autovacuum_naptime into an Interval object once, why can't you just use timestamptz_pl_interval ? You won't be using the interval input/output repeatedly surely. Regards Sailesh -- Sailesh Krishnamurthy Amalgamated Insight [W] (650) 242-3503 [C] (650) 804-6585 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Alvaro Herrera Sent: Wednesday, March 14, 2007 3:46 PM To: Hackers Subject: [HACKERS] how to add seconds to a TimestampTz Is there a better way than going to time_t and back? I am currently using this: db-next_worker = time_t_to_timestamptz(timestamptz_to_time_t(current_time) + autovacuum_naptime); (db-next_worker is a TimestampTz, as is current_time. autovacuum_naptime is integer for a number of seconds) but it doesn't seem clean, and the comments in the functions more or less say that their use is discouraged. I saw about doing it via the interval input/output but that's an awful lot of work ... Is this the first time this is going to be done in the backend? -- Alvaro Herrerahttp://www.CommandPrompt.com/ PostgreSQL Replication, Consulting, Custom Development, 24x7 support ---(end of broadcast)--- TIP 6: explain analyze is your friend ---(end of broadcast)--- TIP 4: Have you searched our list archives? http://archives.postgresql.org
Re: [HACKERS] how to add seconds to a TimestampTz
Grzegorz Jaskiewicz wrote: On Mar 15, 2007, at 5:58 AM, Tom Lane wrote: ? I'm not sure what would be the most convenient realization of this at the C level, but please stay away from time_t ... what's wrong with time_t ? Does postgres has some sort of time API, that can be used instead? Sure. See TimestampTz (as mentioned in the subject). -- Alvaro Herrerahttp://www.CommandPrompt.com/ PostgreSQL Replication, Consulting, Custom Development, 24x7 support ---(end of broadcast)--- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
Re: [HACKERS] how to add seconds to a TimestampTz
Alvaro Herrera [EMAIL PROTECTED] writes: Is there a better way than going to time_t and back? Isn't the standard SQL-level locution timestamptz + numeric_value * '1 second'::interval ? I'm not sure what would be the most convenient realization of this at the C level, but please stay away from time_t ... regards, tom lane ---(end of broadcast)--- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate
