I cleared out the tables AL_CACHE and AL_CACHE_STATS. I then ran the job (with use collected statistics turned on) and it seems to be still using cached statistics. I then also cleared out AL_STATISTICS. The job was executed again and seems to be still using cached statistics.
I then set the job to collect statistics for optimization and ran it. Nothing showed up in AL_CACHE and AL_CACH_STATS. The tables were still empty!
What is going on? Is the job server caching my cache stats in memory? If so, when do they get flushed out to the repository tables?
I think there is something broken in DS 14.1.2.378. When I run the job and tell it to Collect statistics for optimization nothing shows up in the AL_CACHE and AL_CACHE_STATS tables. If I then run the job to Use collected statistics it produces a warning that there are no statistics available.
I looked through the release notes of the patches currently available and I don’t see anything there about this issue being fixed.
In the Knowledgebase I found 1884209:
The jobs I am running have plenty of opportunities for optimization, so I don’t think them being “simple” is the problem.
LOL! I think I figured out the problem. The Export execution Command is generating a Linux shell script that uses -nCollectCacheSize when you specify to “Collect statistics for optimization”. If you run the job from Designer with the same option selection it is using -ncollect_cache_stats. Designer is correct, the Export Execution Command is wrong.
I just discovered the same thing on Windows. Cache options are flipped between Designer and the web console. In addition, it is not appending the option to NOT use collected statistics when run from the web console. I have a ticket open with SAP, but looks like it affects at least 4.1 and 4.2.
In general my experience so far with 4.2 has not been very good (compared to 4.1).
(BOB member since 2007-09-12)