| Subject | Re: [firebird-support] Adding a field with NOT NULL constraint |
|---|---|
| Author | Dimitry Sibiryakov |
| Post date | 2018-02-10T16:48:21Z |
10.02.2018 16:32, Aldo Caruso aldo.caruso@... [firebird-support] wrote:
Default value is returned by select if no field value exists in returned record
version. Engine works about this way:
1) Prepare buffer for returned values and fill it with default values.
2) Replace values in the buffer with values extracted from storage.
3) Send the buffer to client side.
--
WBR, SD.
> I discovered that when a field is added to a table with a NOT NULLNo, it isn't. It would be too slow.
> constraint and a default value, it is automatically filled with that
> default value.
Default value is returned by select if no field value exists in returned record
version. Engine works about this way:
1) Prepare buffer for returned values and fill it with default values.
2) Replace values in the buffer with values extracted from storage.
3) Send the buffer to client side.
--
WBR, SD.