How to Fix Postgres Query Slow After Migration to AWS RDS / Aurora
A query that ran fast on your old PostgreSQL setup is noticeably slower after migrating to RDS or Aurora, even though the hardware specs look comparable or...
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23 results for "Migration"
How to Fix MySQL "Out of Memory" Crash During Large ALTER TABLE Migration
Running an ALTER TABLE on a large table crashes the MySQL server outright with an out-of-memory error, rather than just running slowly. Certain schema changes...
MySQL Column Default Value Expression Invalid Error After Migration
An "invalid default value" error after a migration usually means either your MySQL version's rules around what counts as a valid column default changed, or the...
PostgreSQL Enum Type Migration Failing in Production
PostgreSQL enum migrations failing specifically in production, despite working fine in local testing, is almost always related to ALTER TYPE ... ADD VALUE's...
MySQL "Table Doesn't Exist" After Migration
Getting a "table doesn't exist" error right after running a migration that supposedly created that exact table almost always means the migration either didn't...
How to Fix "PostgreSQL Column Does Not Exist" Casing/Quote Issue
A query references a column you can clearly see in your table definition, but PostgreSQL insists it doesn't exist. This is almost always a case-sensitivity...
How to Resolve "Error 1215 (HY000): Cannot Add Foreign Key Constraint"
Creating or altering a table to add a foreign key fails with a vague error that doesn't say what's actually wrong. Error 1215 is famously unhelpful on its own...
How to Fix "Error 1054 (42S22): Unknown Column in Field List"
A query fails claiming a column doesn't exist, even though you're confident it's really there. This error means MySQL parsed your query successfully but...
How to Fix "fatal: refusing to merge unrelated histories" in Git
You run git pull or git merge and Git stops you cold with a fatal error instead of merging. This happens when Git can't find a common commit ancestor between...