kallithea Files · docs/dev/dbmigrations.rst

Files @ 73e3599971da

Branch filter:

Location: kallithea/docs/dev/dbmigrations.rst

73e3599971da 2.9 KiB text/prs.fallenstein.rst Show Annotation Show as Raw Download as Raw

FUJIWARA Katsunori

journal: make "repository:" filtering condition work as expected (Issue #261)

Before this revision, journal filtering conditions like as below never
match against any entry, even if there are corresponded repositories.

- repository:foo/bar
- repository:foo-bar

Whoosh library, which is used to parse filtering condition, does:

- treat almost all non-alphanumeric characters as delimiter at
parsing condition
- join each conditions at filtering by "AND", by default

For example, filtering condition "repository:foo/bar" is translated as
"repository:foo AND repository:bar". This combined condition never
matches against any entry, because it is impossible that "repository"
field in DBMS table "user_logs" has both "foo" and "bar" values at
same time.

Using TEXT for "repository" of JOURNAL_SCHEMA causes this issue,
because TEXT assumes tokenization at parsing.

In addition to it, using TEXT also causes unintentional ignorance of
"stop words" in filtering conditions. For example, "this", "a", "you",
and so on are ignored at parsing, because these are too generic words
(from point of view of generic "text search").

To make "repository:" filtering condition work as expected, this
revision uses ID instead of TEST for "repository" of
JOURNAL_COLUMN. ID avoids both tokenization and removing "stop words".

This replacement should be safe with already existing DBMS instance,
because:

- JOURNAL_SCHEMA is used only to parse filtering condition
- DBMS table "user_logs" itself is defined by UserLog class
(in kallithea/model/db.py)

BTW, using ID also avoids normalization by lowercase-ing. But this
doesn't violate current case-insensitive search policy, because
LOWER-ing in actual SQL query is achieved by get_filterion() or so in
kallithea/controllers/admin/admin.py.

=======================
Database schema changes
=======================

Kallithea uses Alembic for :ref:`database migrations <upgrade_db>`
(upgrades and downgrades).

If you are developing a Kallithea feature that requires database schema
changes, you should make a matching Alembic database migration script:

1. :ref:`Create a Kallithea configuration and database <setup>` for testing
   the migration script, or use existing ``development.ini`` setup.

   Ensure that this database is up to date with the latest database
   schema *before* the changes you're currently developing. (Do not
   create the database while your new schema changes are applied.)

2. Create a separate throwaway configuration for iterating on the actual
   database changes::

    paster make-config Kallithea temp.ini

   Edit the file to change database settings. SQLite is typically fine,
   but make sure to change the path to e.g. ``temp.db``, to avoid
   clobbering any existing database file.

3. Make your code changes (including database schema changes in ``db.py``).

4. After every database schema change, recreate the throwaway database
   to test the changes::

    rm temp.db
    paster setup-db temp.ini --repos=/var/repos --user=doe --email doe@example.com --password=123456 --no-public-access --force-yes
    paster repo-scan temp.ini

5. Once satisfied with the schema changes, auto-generate a draft Alembic
   script using the development database that has *not* been upgraded.
   (The generated script will upgrade the database to match the code.)

   ::

    alembic -c development.ini revision -m "area: add cool feature" --autogenerate

6. Edit the script to clean it up and fix any problems.

   Note that for changes that simply add columns, it may be appropriate
   to not remove them in the downgrade script (and instead do nothing),
   to avoid the loss of data. Unknown columns will simply be ignored by
   Kallithea versions predating your changes.

7. Run ``alembic -c development.ini upgrade head`` to apply changes to
   the (non-throwaway) database, and test the upgrade script. Also test
   downgrades.

   The included ``development.ini`` has full SQL logging enabled. If
   you're using another configuration file, you may want to enable it
   by setting ``level = DEBUG`` in section ``[handler_console_sql]``.

The Alembic migration script should be committed in the same revision as
the database schema (``db.py``) changes.

See the `Alembic documentation`__ for more information, in particular
the tutorial and the section about auto-generating migration scripts.

.. __: http://alembic.zzzcomputing.com/en/latest/


Troubleshooting
---------------

* If ``alembic --autogenerate`` responds "Target database is not up to
  date", you need to either first use Alembic to upgrade the database
  to the most recent version (before your changes), or recreate the
  database from scratch (without your schema changes applied).