<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><br></div><div>Hmm, the first thing that stands out is the inordinate number of tables.</div><div><br></div><div>Out of curiosity, I tried figuring out what is considered a reasonable number of tables for other database management systems:</div><div><br></div><div>- Oracle: over 10,000 tables considered insane</div><div> (<a href="http://asktom.oracle.com/pls/asktom/f?p=100:11:::::P11_QUESTION_ID:26039880025641">http://asktom.oracle.com/pls/asktom/f?p=100:11:::::P11_QUESTION_ID:26039880025641</a>)</div><div><br></div><div>- Postgres: 10,000 tables works fine; practical limit (on ext3) probably 32k</div><div> (<a href="http://blog.endpoint.com/2008/11/10000-databases-on-postgresql-cluster.html">http://blog.endpoint.com/2008/11/10000-databases-on-postgresql-cluster.html</a>)</div><div><br></div><div>- MySQL Server: no apparent problems</div><div> (<a href="http://stackoverflow.com/questions/610920/maximum-number-of-workable-tables-in-sql-server-and-mysql">http://stackoverflow.com/questions/610920/maximum-number-of-workable-tables-in-sql-server-and-mysql</a>)</div><div><br></div><div>There may be some serialization happening that slows down the table loads. Mnesia is not optimized for this many tables.</div><div><br></div><div>BR,</div><div>Ulf W</div><div><br></div><div><div>On 12 Apr 2012, at 10:35, Kyungho Yun wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>It usually takes 50 minutes to startup mnesia.</div><div>It is too long.</div><div><br></div><div>Here is my conditions:</div><div> - DB exists local</div><div> - more than 60000 tables</div><div> - sum size is about 28 Giga Bytes.</div>
<div> - most tables created options with record_name, attributes(and record_info()) and disc_only_copies.</div><div> - startup after normal exit (not crash)</div><div> - R14B04, no_table_loaders 10000</div><div><br></div>
<div>I've searched many websites, read documents here and other places, changed options.</div><div>but the elapse of mnesia startup wasn't decrease.</div><div><br></div><div>Here is what I controlled:</div><div> - ulimit -n</div>
<div> - no_table_loader, +A, +K, +P, +zdbbl, dc_dump_limit</div><div> - add option local_content when create table</div><div> - io schedule type</div><div><br></div><div>finally, I am curious mnesia I/O ability.</div><div>
few blocks/s value(about 2000) is shown in iostat during mnesia startup,</div><div>but it's very big blocks/s value (bigger than 100000) is shown during copy something.</div><div><br></div><div>How to speed up mnesia startup?</div>
<div>Tell me a clue please.</div><div><br></div><div>thanks</div><div><br></div>
_______________________________________________<br>erlang-questions mailing list<br><a href="mailto:erlang-questions@erlang.org">erlang-questions@erlang.org</a><br>http://erlang.org/mailman/listinfo/erlang-questions<br></blockquote></div><br><div apple-content-edited="true">
<div><div>Ulf Wiger, Co-founder & Developer Advocate, Feuerlabs Inc.</div><div><a href="http://feuerlabs.com">http://feuerlabs.com</a></div></div><div><br></div><br class="Apple-interchange-newline">
</div>
<br></body></html>