Moving data sounds like the easiest phase of a migration: the table is there, pour the data in, done. Until the first larger table takes a whole afternoon — because it runs row by row via INSERT instead of in one sweep via COPY. Anyone who needs to load data into PostgreSQL has four routes to choose from, and the … Read more
A SQL Server to PostgreSQL schema migration looks finished the moment the CREATE TABLE script runs without an error. That is exactly when the real trouble begins: the table is there, the data is loaded — and the first INSERT that should hand out a new ID collides with an existing key. The reason is not a typo but a change … Read more
A migration from SQL Server to PostgreSQL rarely fails at actually copying the data. It fails at datetime, where the choice between timestamp and timestamptz is anything but cosmetic, at bit, which is not a boolean, and at money, which you’d be better off not touching in PostgreSQL at all. The SQL Server to PostgreSQL data type mapping decides whether the data arrives cleanly — … Read more
