Re:Interbase VARCHAR datatype
Quote
Keith Edmunds (k...@itworks.demon.co.uk) wrote:
: What's the overhead of VARCHAR datatypes? If I define a field as
: VARCHAR(10000) and store a one-character string in it, how much space
: (approximately) is taken up? I'm trying to decide whether to use a BLOB
: field or a large VARCHAR field for my application.
: Is this the best place for Interbase questions/discussion? I couldn't see a
: news group for Interbase.
A varchar only occupies the required amount of space to hold the column
in the row. IB actually performs run length encoding of a row anyway thus
you typically find that there is less of a footprint for your data as a
whole than you'd presume assuming lots of repetitous bytes in the rows.
A Blob is held in separate page space to the row (row contains a quad-word
pointer to where the blob data is held). Unlike regular types, InterBase
does not compress or perform machine translations (such as from VAX to
HPUX). You could of course roll your own filters which is more effort.
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