Mike Charnoky wrote: > Our database schema was designed before postgresql supported arrays and > contains a custom type which is basically a float4 array. I would like > to clean things up and convert the custom datatype to float4[], as this > would obviate the need for us to compile a custom shared object. We are > hitting problems with pg8.3 and I would rather just drop the custom stuff. > > Problem is, I cannot do an ALTER COLUMN: > > mydb=# alter table mytable alter column mycolumn float4[]; > ERROR: column "mycolumn" cannot be cast to type "float4[]"
You can specify a USING clause to let the system know exactly how to convert your type to float[]. I suspect you can use float4in() and something to read out your type into the format that float4in expects (a hacked up version of your out function perhaps). -- Alvaro Herrera http://www.amazon.com/gp/registry/5ZYLFMCVHXC "La tristeza es un muro entre dos jardines" (Khalil Gibran) ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
