Any implications of changing the type of a property of a persistent class from Timestamp to String?
In a typical database, changing the type of a column from some kind of date/time to a string would require a degree of migration effort for existing values. In Caché, my suspicion is that this is not the case, and I could simply change a property definition from %Timestamp to %String (MAXLEN = "30") and recompile, without needing to worry about damaging the existing data stored for this property. Is this correct? Or would I find the existing data in this property being lost or corrupted?
Thanks in anticipation
Comments
You can change the definition, the data remains as is. But you have to take care about your applications, like SQL-queries. For example a DATEPART() function could refuse to work because a property, defined as %String, may contain everything.
Also, any indices on such field would need to be rebuild. Indices on %String properties are expected to start with an empty space thus your queries using these indices won't return any existing (non-updated) rows.
except if ... As %String(COLLATION = "EXACT");
But rebuild of indices is still a must or good practice