On Wed, 28 Oct 2015 23:59:59 +0100, "setysvar setysvar@...
[firebird-support]" <firebird-support@yahoogroups.com> wrote:

> http://tracker.firebirdsql.org/browse/CORE-4601 is a report of a 60-time

> improvement (from half a minute to half a second) with Firebird
> 2.5.2/2.5.3 and Jaybird 2.2.5/2.1.6 when changing from blob to varchar,
> I guess this could be the same problem as you observe.

CORE-4601 is not a bug, it is an improvement request. The described
behavior is inherent to the way blobs are handled in the wire protocol of
Firebird, and I don't think it is the cause of this problem (it would also
- as far as I know - not explain the high CPU use).

Mark