Re: [RFC] News Item: KDE PIM 26.04.1 default backend changes to sqlite

11.05.2026 23:15, Andreas Sturmlechner пишет:
> Title: KDE PIM 26.04.1 default backend changes to sqlite
> Author: Andreas Sturmlechner <[email protected]>
> Posted: 2026-05-15
> Revision: 1
> News-Item-Format: 2.0
> Display-If-Installed: kde-apps/akonadi
>
>
> KDE PIM's centralised Akonadi subsystem is using a database for cached data.
> For this, three different database backends are supported for a long time.
> When multiple USE flags are enabled, kde-apps/akonadi-config ebuild picks
> the one with highest priority as default DB backend in akonadiserverrc.
>
> ---------!--------------------------------!-----------!-----------
>   Backend ! kde-apps/akonadi-config[<use>] ! <=26.04.0 ! >=26.04.1
> ---------!--------------------------------!-----------!-----------
>   QSQLITE ! sqlite                         !     2     !     1
>   QMYSQL  ! mysql                          !     1     !     2
>   QPSQL   ! postgres                       !     3     !     3
>                                            !  (priority, 1 = best)
>
> This means that prior to KDE PIM 26.04.1 (with kde-apps/akonadi-config-0),
> mysql, when enabled, took precedence for new KDE PIM setups.
>
>
> Changes
> =======
>
> With kde-apps/akonadi-config-1 we are making sqlite first choice instead.
> That in itself will not change existing Akonadi instance settings, which
> are stored in home directories.
>
>
> Reasons
> =======
>
> Historically[1], QSQLITE backend was fundamentally broken for KMail workload,
> which is why QMYSQL was picked as default early on. Over the years this has
> come with its own share of (mostly DB upgrade handling) bugs, but QSQLITE has
> only in recent years become viable again through upstream's efforts, which we
> have been tracking[2]. Recently, the default was finally changed uptream[3].
>
>
> User Action Required
> ====================
>
> In order to implement any backend change on your users' akonadi DB config,
> a manual migration step is necessary - in this example, from mysql to sqlite.
> It is necessary to have support for both database drivers enabled in
> dev-qt/qtbase for this to succeed.
>
>      1) Find out which backend is currently in use:
>
>          grep ^Driver ~/.config/akonadi/akonadiserverrc

"^Driver" needs to be quoted. On my zsh without quotes it did...
something else.


>
>      2) A quick check that both DB drivers are supported by Qt:
>
>          USE="mysql sqlite" emerge -p1 dev-qt/qtbase
>
>          If this command indicates a USE flag change, you must at least
>          temporarily rebuild dev-qt/qtbase with both old and new enabled.
>
>      3) Migration:
>
>          akonadi-db-migrator --newengine sqlite
>
>      The last command will not just migrate the database but also adapt
>      akonadiserverrc accordingly.
>
> In order to keep using QMYSQL backend for users' existing Akonadi instances,
> ensure that USE=mysql is permanently[4] enabled for kde-apps/akonadi-config
> [and dev-qt/qtbase respectively].
>
> In order to keep QMYSQL backend as default choice for new Akonadi instances,
> make sure that USE=sqlite is disabled for kde-apps/akonadi-config.
>
>      Remember to run dispatch-conf (preferred) or etc-update to get updated
>      configuration files:
>
>          dispatch-conf
>
>
> [1] https://bugs.gentoo.org/441596
> [2] https://bugs.gentoo.org/936102
> [3] https://invent.kde.org/pim/akonadi/-/merge_requests/311
> [4] https://wiki.gentoo.org/wiki//etc/portage/package.use