Re: Timing of SAVLIB/RSTLIB vs CPYLIB

[Vern Hamberg <vhamberg@xxxxxxxxxxx>]

 CPYLIB uses CRTDUPOBJ for every object. It has to determine the 
correct order for object dependencies, then it uses CRTDUPOBJ on each. 
RSTLIB, esp. if you have saved access paths, will be faster, because the 
SAV/RST code path is optimized for throughput.

Vern

On 9/9/2010 7:52 PM, Lennon_s_j@xxxxxxxxxxx wrote:
> Curiosity question.
>
> Each night in the wee hours we create a test environment from a
> production library, thus:
> 	SAVLIB PROD01 to QTEMP/SAVF
> 	CLRLIB TST01
> 	RSTLIB QTEMPSAVF to TST01
>
> It runs in about 41-45 minutes.
>
> Last night I had to do a (occasional) copy of T01 to T02.  I did this:
> 	CLRLIB T02
> 	CPYLIB T01 to T02
>
> It took 45 minutes.  I figured creating T02 this way would be quite a
> bit faster than creating T01, but it wasn’t.
>
> T01 was created about 3-3:45 am.  T02 was created 4:30-5:15 am.  There
> is really nothing else running at these times.
>
> Any thoughts on why the CPYLIB approach is not faster?   CPYLIB did seem
> to do a lot of index rebuilding (observed in a test during the day.)
> Maybe SAVLIB/RSTLIB is smarter about indexes and/or does more in parallel.