Loading Mnesia dbase

Thu Nov 24 16:55:22 CET 2005

I decided to retest using fragmented tables (15 fragments) and I/O threads. Also I did the inserts in stages. The first 9 million records to ram_copy went in below 7 mins. The change table to disc_copy took 0.6 mins. A mnesia backup worked fine (< 13 mins) but it failed on the restore (unable to allocated heap). I proceeded with a fallback which worked well.

The next 3 million records went into disc_copy with warning messages: 

       Mnesia is overloaded: {dump_log, write_threshold}

(see discussion: http://www.erlang.org/ml-archive/erlang-questions/200007/msg00098.html)

It however stablized and the records were in. 

The final 2 million failed to get in with a couple hundred missing records. Their insertion processes died. I redid the missing entries and have all 14 million records in. The erl shell is now at a crawl but now using a good 1.8 GB of the 2 GB RAM.

The two things I found helped was increasing I/O threads (erl +A) and using fragmented tables. I suspect more RAM would improve things greatly. 

Thanks for the help.


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