Andrew Farries 9a08b6cc77 Implement Start for adding columns with NOT NULL and no DEFAULT (#37) ... Implement `Start` for **add column** operations that add a `NOT NULL` column without a `DEFAULT`. To add such a column without forcing a exclusive lock while a full table scan is performed, these steps need to be followed: On `Start`: 1. Add the new column 2. Add a `CHECK IS NOT NULL` constraint to the new column, but with `NOT VALID`, to avoid the scan. 3. Backfill the new column with the provided `up` SQL. On `Complete` 1. Validate the constraint (with `ALTER TABLE VALIDATE CONSTRAINT`). 2. Add the `NOT NULL` attribute to the column. The presence of a valid `NOT NULL` constraint on the column means that adding `NOT NULL` to the column does not perform a full table scan. See [this post](https://medium.com/paypal-tech/postgresql-at-scale-database-schema-changes-without-downtime-20d3749ed680#00dc) for a summary of these steps.		2023-07-21 07:47:42 +01:00
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01_create_tables.json	Format the examples with jq (#21)	2023-07-06 15:26:29 +01:00
02_create_another_table.json	Format the examples with jq (#21)	2023-07-06 15:26:29 +01:00
03_add_column.json	Implement Start for adding columns with NOT NULL and no DEFAULT (#37)	2023-07-21 07:47:42 +01:00
04_rename_table.json	Rename table op (#23)	2023-07-11 08:01:05 +00:00