Hi, I have a doubt (maybe this was already discussed)

I create this simple table in FB 2.1

CREATE TABLE "Configuracion" (
"Item" VARCHAR(32) NOT NULL,
"ValorTexto" VARCHAR(120) NOT NULL,
"ValorReal" DOUBLE PRECISION NOT NULL,
"ValorEntero" INTEGER NOT NULL
);

ALTER TABLE "Configuracion"
ADD PRIMARY KEY ("Item");

when I want to insert some records I notice that one has a longer text for field "Item" so
I decided to change the column size from VARCHAR(32) to VARCHAR(64) but the following
error arises:

SQL Error: unsuccessful metadata update MODIFY RDB$RELATION_FIELDS failed action
cancelled by trigger (1) to preserve data integrity Cannot update index segment used by an
Integrity Constraint. Error Code: -607. This operation is not defined for system tables.
The SQL:

ALTER TABLE "Configuracion"
ALTER COLUMN "Item" TYPE VARCHAR(64);

The table isn't has no relationships with any other and I imagine that the "constraint" is
the primary index. Is there a way to modify table columns without errors because, for
e.g., converting an INTEGER column to DOUBLE PRECISION gives errors too.

To resume, it is almost impossible to make changes to columns, at least, via alter table.
How can I circumvent this?

Best regards,
Mauro H. Leggieri