From kde-pim Fri Feb 24 13:18:35 2012 From: Will Stephenson Date: Fri, 24 Feb 2012 13:18:35 +0000 To: kde-pim Subject: Re: [Kde-pim] Akonadi db schema change needed to store search folder queryStrings Message-Id: <1371009.lC7GoMnUTp () emsig> X-MARC-Message: https://marc.info/?l=kde-pim&m=133008956303103 On Friday 24 Feb 2012 13:28:06 you wrote: > On Friday 24 February 2012 09:52:37 Will Stephenson wrote: > > On Thursday 23 Feb 2012 22:26:49 Shaheed Haque wrote: > > > Is the extra storage really a concern? I suppose the pimitemtable is > > > probably going to have most entries by far. That seems to have a > > > handful of columns which might be strings (and 9 in total). Even if I > > > had a million records, we are talking a handful of MB. > > > > > > That seems perfectly reasonable...Or have I misunderstood? > > > > Multiplying the number of rows by the number of QString columns and > > summing > > it across all tables gives me (2 imap accounts, about 2.5GB mail in total > > on the servers) an additional 1455755 bytes for the storage. Then I assume > > indexed columns count double, which gives another 872906 * 2 bytes as > > there > > are 2 indices on parttable.name (which contains a lot of repeated entries, > > perhaps it would make sense to normalize this out into its own table?). > > > > That's 3201567 extra bytes in theory. I'm not a database guy so don't > > know > > how that translates into real extra storage, memory footprint (indexes > > stay > > in memory, right?) and performance. Can someone better informed comment? > > VARBINARY has variable length, hence it will only use as much as it actually > needs. The number you pass it is the maximum size. I'm on kde-pim@, no need to CC me. In my reading of the manual, VARBINARY has the same storage requirements as VARCHAR, which means, it requires length(data) bytes, plus one byte for len <=255, else plus 2 bytes. It's in the manual. I suppose it uses either a byte or a short for the field length. Will _______________________________________________ KDE PIM mailing list kde-pim@kde.org https://mail.kde.org/mailman/listinfo/kde-pim KDE PIM home page at http://pim.kde.org/