Confirming \timing output

On Aug 23, 2012, at 11:13 AM, "Gauthier, Dave" <dave.gauthier@intel.com> wrote:

With \timing set on, I run an update statement and it reports....

Time: 0.524 ms

Is that really 0.524 ms? As in 524 nanoseconds?

0.524ms = 524000ns

Perhaps you meant microseconds?

0.524ms = 524us

If all your data happens to be in RAM cache, simple queries can execute very fast! Unless you have a reason to believe it's wrong, I would trust it to be accurate :-)

Also, is this wallclock time or some sort of indication of how much cpu it took?

Thanks for any answers !

\timing measures wall time. There's a more detailed discussion of the difference between this and e.g. EXPLAIN ANALYZE here:

http://postgresql.1045698.n5.nabble.com/What-does-timing-measure-td4289329.html

On 08/23/12 11:13 AM, Gauthier, Dave wrote:

Time: 0.524 ms

Is that really 0.524 ms? As in 524 nanoseconds?

0.524 MILLIseconds. as in 524 microseconds. microseconds is commonly
abbreviated us.

afaik, its elapsed time, not CPU time.

--
john r pierce N 37, W 122
santa cruz ca mid-left coast

On 08/24/2012 02:30 AM, John R Pierce wrote:

On 08/23/12 11:13 AM, Gauthier, Dave wrote:

Time: 0.524 ms

Is that really 0.524 ms? As in 524 nanoseconds?

0.524 MILLIseconds. as in 524 microseconds. microseconds is commonly
abbreviated us.

They should be �s ; (micro � seconds s). Sadly, many setups still can't
type anything outside 7-bit ASCII even in 2012 :-(

--
Craig Ringer

On 08/23/12 7:31 PM, Craig Ringer wrote:

0.524 MILLIseconds. as in 524 microseconds. microseconds is commonly
abbreviated us.

They should be µs ; (micro µ seconds s). Sadly, many setups still
can't type anything outside 7-bit ASCII even in 2012

yeah, I know I could enter the alt+xyz except this laptop keyboard
doesn't have a number pad, and I was way way too lazy to find and
copy/paste one, or to use charmap.

--
john r pierce N 37, W 122
santa cruz ca mid-left coast