South New and Old

Transcript

1. 1.

   new and old south Andrew Godwin djangocon.eu 2010

2. 2.

   It's been almost 2 years. Lots has happened.

3. 3.

   Migrations? Eh? A bit like a VCS, but for database

   schemas.
4. 4.

   The Beginning

5. 5.

   1-make_tables.sql 2-add_profile.sql

6. 6.

   YOU ARE AT VERSION 2 1-make_tables.sql 2-add_profile.sql

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   1-make_tables.sql 2-add_profile.sql 3-remove_pony.sql 1-make_tables.sql 2-add_profile.sql 4-add_postcode.sql

8. 8.

   1-make_tables.sql 2-add_profile.sql 3-remove_pony.sql 1-make_tables.sql 2-add_profile.sql 4-add_postcode.sql YOU ARE AT VERSION

   3 YOU ARE AT VERSION 4
9. 9.

   1-make_tables.sql 2-add_profile.sql 3-remove_pony.sql 1-make_tables.sql 2-add_profile.sql 4-add_postcode.sql YOU ARE AT VERSION

   3 YOU ARE AT VERSION 4 3-remove_pony.sql 4-add_postcode.sql
10. 10.

    Oracle MySQL PostgreSQL MSSQL SQLite

11. 11.

    The Early Days

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    Adding tables Deleting tables Everything else useful

13. 13.

    3-remove_pony.sql 1-make_tables.sql 2-add_profile.sql 4-add_postcode.sql

14. 14.

    Uh-oh, publicity

15. 15.

    Closing this, as it's unlikely we'll write a model history

    tracker in the near future, and django-evolution does this well - no need to reinvent the wheel in that area. “ “
16. 16.

    Feature Creep (of the good sort)

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    start_field_re = re.compile(r'\s*%s\s*=\s*(.*)' % field.name) for line in source[0]: #

    if the field was found during a previous iteration, # we're here because the field spans across multiple lines # append the current line and try again
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    cms.0001_initial cms.0002_auto_start picture.0001_initial file.0001_initial flash.0001_initial link.0001_initial snippet.0001_initial video.0001_initial twitter.0001_initial cms.0003_remove_placeholder

    cms.0004_textobjects cms.0005_mptt_added_to_plugins cms.0006_apphook text.0001_initial cms.0007_apphook_longer cms.0008_redirects cms.0009_added_meta_fields cms.0010_5char_language cms.0011_title_overwrites cms.0012_publisher cms.0013_site_copy file.0003_publisher text.0003_publisher picture.0004_publisher googlemap.0001_initial link.0005_publisher flash.0003_publisher snippet.0002_publisher cms.0014_sites_removed cms.0015_modified_by_added cms.0016_author_copy cms.0017_author_removed cms.0018_site_permissions cms.0019_public_table_renames file.0004_table_rename cms.0020_advanced_permissions picture.0006_float_added teaser.0001_initial text.0004_table_rename flash.0004_table_rename link.0006_table_rename snippet.0003_table_rename googlemap.0002_table_rename picture.0005_table_rename cms.0021_publisher2 picture.0007_publisher2 cms.0022_login_required_added teaser.0002_publisher2 cms.0023_plugin_table_naming_function_changed text.0002_freeze text.0005_publisher2 picture.0002_link_rename picture.0003_freeze picture.0008_longdesc_added file.0002_freeze file.0005_publisher2 flash.0002_freeze flash.0005_publisher2 link.0002_link_rename link.0003_page_link link.0004_larger_link_names link.0007_publisher2 link.0008_mailto snippet.0004_publisher2 snippet.0005_template_added googlemap.0006_publisher2 googlemap.0007_latlng googlemap.0008_routeplaner googlemap.0009_routeplaner_title video.0002_color_mute_controller video.0003_newplayer_step1 video.0004_newplayer_step2 video.0005_newplayer_step3 video.0006_newplayer_step4 video.0007_newplayer_step5 inherit.0001_initial inherit.0002_fieldchanges
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    Model Freezing

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    Historical ORM access Automatic change detection ‘Improved’ model parsing

21. 21.

    Sanity Dawns

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    Introspection Magically supports custom fields Prevents hideous migration failure

23. 23.

    SQLite Make new table Copy data from old table Delete

    old table Rename new table
24. 24.

    Signals Speed Simplicity

25. 25.

    1.0

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    MultiDB? Non-relational? Renames!

27. 27.

    Organic Growth But it's still cleanly separated

28. 28.

    Database Backend Dependency/ Ordering Engine Migration Runner Auto- detector

29. 29.

    The Future

30. 30.

    Database Backend Dependency/ Ordering Engine South in future ??? Migration

    Runner Auto- detector
31. 31.

    The Ultimate Goal

32. 32.

    Andrew Godwin Fin. www.aeracode.org @andrewgodwin

33. 33.

    Andrew Godwin Fin. www.aeracode.org @andrewgodwin