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Re: MySQL
by Till Adam on Thursday 26/Apr/2007, @03:57

Akonadi uses the database to store metadata and usually relies on external providers/agents/ressources for the actual storage. In the mail case, for example, your mail would be in a maildir, and only a cache of things like the headers or a summary along with transient info like tags, colors, etc. would end up in the db, for easy and fast indexing, searching, etc. It can cache the payload data itself as well, though, to avoid unnessecary re-downloads, or to make offline work possible, in which case the data does end up in the database. Currently it can work with MySQL embedded and a MySQL server, so if you don't want to have a full on server running, you can simply use the single-file engine, which works much like, for example, sqlite. The database in this case is completely transparent to the user. It's merely an implementation detail, and if you happen to be running MySQL anyhow, for Amarok, KPhotoAlbum, or what have you, it can use that too. Does that clarify it a bit?

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Re: MySQL
by Jakob Petsovits on Thursday 26/Apr/2007, @07:28

> Akonadi uses the database to store metadata and usually relies
> on external providers/agents/ressources for the actual storage.

Hm, that sounds a lot like it could make use of Nepomuk's KMetaData.
No idea if that satisfies Akonadi's performance criteria, though.

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Re: MySQL
by Till Adam on Friday 27/Apr/2007, @02:56

There's a demo feeder for Nepomuk, but we also store information that Nepomuk is not interested in. Sure, we'll use it.

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Re: MySQL
by Ben on Thursday 26/Apr/2007, @12:58

And out of curiosoty, why when caching the E-mail payload will the entire E-mail go into the database, instead of another maildir?

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Re: MySQL
by Till Adam on Friday 27/Apr/2007, @02:53

The idea is to keep the resources (the bits that know how to deal with a storage format, or groupware server) as simple as possible, which includes them not having to re-implement cache mechanisms over and over again, as was needed with the old kresources framework. So conceptually all caching is done inside Akonadi. We might special case well-known formats such as email to use a different on-disk store, for example maildir, for performance and robustness reasons, but in the general case the database acts as the cache. Much of the data is small (contacts, events, chat logs, etc.) and can thus be stored very efficiently in the db itself.

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