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Old 2021-02-19, 17:39   #813
garambois
 
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"Garambois Jean-Luc"
Oct 2011
France

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Quote:
Originally Posted by EdH View Post
I'm doing some experiments now, that will provide some better info, but initial results seem to point to me being able to get all 27645 sequences in a timely manner, and then use the local set for all my "playing."

My overall intention is to create a local set of all open sequences (<3M). Then, create scripts (or C++ programs) for the following:
- Update entire set by comparing last lines and only retrieving sequences that have changed since the last time run - to be used only a couple times a year.
- Create lists of last occurrences of various digit sizes (C9/C30/C60/C80).
- Check for merges against local sequences rather than the db. Since the C80 listing will reflect data harvested from the local set, there should not be a need to check against the db.
- Whatever else I may think of.

I already have a local copy of all the sequences in the base tables, and a method to update all open sequences in all the tables. I should be able to create a script to harvest C9/C30/C60/C80 lists from that, as well. I will consider it.

Of course, all this hinges on my ability to actually create the scripts. But, I will update here as I progress.

I will follow your work closely if you share it with us here.

At the moment, I'm having a hard time figuring out the usefulness of creating a list of the last occurrences of various digit size : C9 / C30 / C60 / C80.
Isn't it enough to create C80 ? With C80, you are sure to find the right fusion sequence. The risk that a C9 belongs to two sequences of the main project does not seem negligible to me, but it should be checked.
Also, if a sequence is yo-yoing, there is no reason the merge occurred during the last "low peak". The merger may have occurred on an earlier "low peak" (Merges almost always occur on the low peaks).
But you must have your reasons for wanting to create lists of last occurrences of various digit sizes (C9/C30/C60/C80).



Quote:
Originally Posted by EdH View Post
Edit: It looks like I'm able to d/l 1000 .elfs in a little over two hours without the db being anywhere near complaining. I don't plan to let it run unattended overnight, so I'm probably looking at a few days to complete the set. But, I don't need the full set to begin writing scripts.

1000 downloads of .elf in 2 hours : This is not at all what I experienced in April 2020. I had instead a speed of an .elf file in 60 seconds.
So this is very good news, maybe factodb's server is much faster now. I will give it a try over the next week.



Quote:
Originally Posted by EdH View Post
I also intend to search the new set for any new merges or terminations that may have occurred. I plan to have that done by the script(s), to try to remove as much as possible the need for manual intervention.

I do wonder how much the list will have really changed over the past 9 months. Most of those sequences were well over 80 digits and probably few fell that far again. A quick examination of the first 100 sequences didn't reveal any difference between a new list and last year's. But, then, again, most of the work was probably in the higher sequences.

There really isn't a lot of change in a year. Each year you have to delete the sequences that have ended or that have merged with a smaller one from the main project.
These are the ones that are reported on the last pages of this topic :
https://www.mersenneforum.org/showthread.php?t=11837
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