On Wed, 2006-03-15 at 08:13 -0500, Alexandre Leclerc wrote: > On 3/15/06, Joost van der Sluis <[EMAIL PROTECTED]> wrote: > > A varchar can hold 2000 characters in sqldb. Postgres supports up to > > 8192 characters in a varchar. If you really need 8192 characters, it's > > easy to update sqldb, just set this value on top of db.pp. > > I though that there were absolutely no limits in length with a varchar > that has no limit specifier. > > The varchar type is the ideal field for a memo. It take only the > required length and the overhead is not big. There are also no known > speed issues on the DB side when working with this type - I asked > postgres people for that since in many DB there is a speed issue when > using that kind of fields.
You are right, I confused PostgreSQL with another DBMS. But the limit for a string in sqldb is really there. I've changed PQConnection so that a text field is also interpreted as a varchar. But I don't agree that you can use this or a varchar like a BLOB-field. It's true that they are unlimited, (up to 1 GB) but the problem is that they are handled like a normal field. Thus if you do a request for a record, the field is send in that request. Normally, a BLOB-field is not send with the record, but only if you specially ask for the data in the blob. SQLDB always buffers all the records. Thus if you have a unlimited varchar, sqldb will allocate approximate 2000 (the max) bytes for this field for every record. Keep that in mind while you're designing your database. -- Met vriendelijke groeten, Joost van der Sluis CNOC Informatiesystemen en Netwerken http://www.cnoc.nl _________________________________________________________________ To unsubscribe: mail [EMAIL PROTECTED] with "unsubscribe" as the Subject archives at http://www.lazarus.freepascal.org/mailarchives
