Database / Mnesia intermediate to advanced Interview questions
What is the dc_dump_limit configuration parameter used for?
Mnesia doesn't write every single transaction directly and immediately into a disc_copies table's on-disk
data file — it appends to a transaction log first, periodically "dumping" that log into the actual table
files. dc_dump_limit controls how large that log is allowed to grow (as a multiple of the table's
own data file size) before Mnesia forces a dump.
%% in sys.config {mnesia, [{dc_dump_limit, 40}]}.
A higher limit lets more writes accumulate in the (cheaper-to-append) log before triggering the heavier work of dumping into the actual table file, which can improve raw write throughput at the cost of a longer log to replay if the node restarts before the next dump. Tuning it is a tradeoff between steady-state write throughput and how long recovery/restart takes afterward.
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