Subject Re: elementary question, blob versus varchar in ib
Author Aage Johansen
Daniel Rail wrote:
> ...
> ... The only downside to using blobs is that
> they are not searchable just using a SELECT statement, you might have to
> implement your own search methods or use a full text search engine as the
> one that Jason has. By giving a blob to your customer, you wont be bugged
> anymore to increase the comment field size.

You can search the blobs with " ... where MYBLOB containing 'xyz' ...",
which does a case insensitive search. Indexes do not apply, so indexed
search will require some additional device.


> On the other hand, increasing the field from varchar(40) to varchar(100)
> isn't much of a deal. As mentioned before, the size stored in the database
> is the same concept, but you will be transferring 100 characters instead of
> 40 characters to your application.
> ...

As for space, remember also that fields are compressed on disk. However,
the fields will - as you say - be transferred fully expanded. I think
IB/6.5 now transfers varchars more efficiently.


Regards,
Aage J.