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32 lines
1.1 KiB
32 lines
1.1 KiB
class StatusIdsToTimestampIds < ActiveRecord::Migration[5.1] |
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def up |
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# Prepare the function we will use to generate IDs. |
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Mastodon::Snowflake.define_timestamp_id |
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# Set up the statuses.id column to use our timestamp-based IDs. |
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ActiveRecord::Base.connection.execute(<<~SQL) |
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ALTER TABLE statuses |
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ALTER COLUMN id |
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SET DEFAULT timestamp_id('statuses') |
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SQL |
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# Make sure we have a sequence to use. |
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Mastodon::Snowflake.ensure_id_sequences_exist |
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end |
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def down |
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# Revert the column to the old method of just using the sequence |
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# value for new IDs. Set the current ID sequence to the maximum |
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# existing ID, such that the next sequence will be one higher. |
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# We lock the table during this so that the ID won't get clobbered, |
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# but ID is indexed, so this should be a fast operation. |
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ActiveRecord::Base.connection.execute(<<~SQL) |
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LOCK statuses; |
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SELECT setval('statuses_id_seq', (SELECT MAX(id) FROM statuses)); |
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ALTER TABLE statuses |
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ALTER COLUMN id |
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SET DEFAULT nextval('statuses_id_seq'); |
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SQL |
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end |
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end
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