A Unique constraint is used to enforce unique values across one or many columns, often applied against Alternate keys of a table. Sometimes you want uniqueness enforced only where data for a column is present, and not where values are Null, for example, when storing optional Person attributes such as National Insurance numbers or Driving Licence numbers. Section 5.3.3. Unique…
An odd ‘feature’ of T-SQL that once sent me on a wild goose chase. If you try to cast an integer to a smaller length char/varchar data type, the database engine silently casts the value to an asterisk ‘*’. This is also true for when you rely on an implicit cast such as during an Insert.
SELECT CAST(1500 AS VARCHAR(2)) AS Varchar2, CAST(1500 AS CHAR(3)) AS Char3;
You’ve spent thousands on a shiny new server. Before you go ahead and configure your database environment, now is a good time to tune the software side of your storage subsystem for optimal performance. SQLIO is a Command Line IO benchmarking utility for Windows which can help you do just that. For Linux, consider utilities such as fio or bonnie++.…
X2Go is my favourite remote desktop solution for Linux, mainly because its so responsive. Hopefully I’ll write up a quick How To on getting it setup soon, but for now, here’s an issue I’ve just overcome after a couple of days of stress! Issue SSH connection to my home server was working fine but X2go had stopped working. This…