Unable to set default on JSON column in mysql 8.0.31
I’m trying to set a default for a new JSON column in a mysql 8.0.31 db. As far as I am aware, this wasn’t possible till version 8.0.13. Starting with version 8.0.13, it should be possible to set this as long as the value is an expression, e.g. DEFAULT ('[]')
.
MySQL permit read access during table alter
When i alter a table, for instance, change a field from char to varchar, any user doing a select operation on that table has to wait for the alter table operation to succeed. Some tables contain 100s of millions of records and the alter table operation can take an hour or more.