NULL VarCharString (was Slow NOT searches)

[jda]

>Advantage of making a VarChar field nullable is that you would be able to
>distinguish between when a field legitimately contains an empty string,
>either by default or explicit assignment, and when it contains no string at
>all because none has been supplied for it.  You could achieve the same
>result by choosing some arbitrary string of your choice to signify "no
>string supplied", such as "NULL" for example.
>
>Disadvantages are more storage required for storing the per-record isNull
>information, and slower execution because the nullable information needs to
>be taken into consideration for many operations you may perform on the
>field.
>
>That make sense?
>
>--Ed
>

It would, Ed. But I tested this after posting, and searching for 
WHERE varCharField IS NULL got nothing (all fields had been created 
after SetBlank). Whereas searching for WHERE varCharField IS NOT NULL 
returned all. So I'm thinking that Valentina ignores Nullable for 
varCharFields. Is that right, Ruslan?

Jon