monty@delphi.uchicago.edu (Monty Mullig) (02/03/90)
david masterson writes, including segments of my posting: >> to my mind, a variable length field is one in which no fixed maximum >> or minimum is specified by the user. >Fine, but what is the purpose of such a field? Where would you make >use of it >and why? What problems are incurred with being "forced" to specify a maximum? the person defining the database may not know how long a field will be. text, comments, and memo fields might be very difficult to estimate how long the maximum might be. you might define what the system maximum is and make a declaration like: fieldname vchar[SYSMAX]; but if the system maximum increases, you'll need to update all instances of where the SYSMAX constant is set. easier to let the system decide its maximum and just declare something like: fieldname varlen; >> now, the system might place some restrictions on the size of the >> field, such as it must be between 0 and 65,534 bytes long, but the >> user doesn't specify a limit. >How would it differ from a LONG VARCHAR field (DEC RDB terminology, I think) >in which the upper limit isn't specified, but its certainly known (65536)? i don't know that it would differ.
peter@doe.utoronto.ca (Peter Mielke) (01/16/91)
I'm looking for a relational database system that support fields of variable length text. What sort of systems are there available and what sort of hard limits are there to the text length? Mail replies to me and i will summarize... Thanks, -- Peter Mielke peter@doe.utoronto.ca Dictionary of Old English Project utgpu!utzoo!utdoe!peter University of Toronto
peter@doe.utoronto.ca (Peter Mielke) (01/24/91)
A few days i wrote: > > I'm looking for a relational database system that support fields of > variable length text. What sort of systems are there available and > what sort of hard limits are there to the text length? Well here is a summary of the replies i got: Name Maximum size of variable length field Progress 32K Sybase 2147K Informix 2 gigabytes Spires ? Oracle 64K Unify ? KnowledgMan, 3.0 ? Empress 2147K (the maximum value of int on the machine) Where ? represents it does have variable length field data type but the the person who replied didn't know the limit. Thanks to all who replied... dawn <ledbette@watserv1.uwaterloo.ca> wlb@pscdev.progress.COM (Warren Bare) westbr@vehka.cs.uta.fi (Harri L{nsipuro) zhang@cs.sfu.ca dberg@cougar.informix.com (David I. Berg) ubiquity@cs.utexas.edu (Richard Hoffman) "Diana Gregory" <HXKPY%SLACVM.bitnet@ugw.utcs.utoronto.ca> Bjorn Engsig <bengsig@dk.oracle.com> ewoods@hemel.bull.co.uk (Eoin Woods) bjorn@lexis.hi.is (Bjorn Svavarsson) dmg@kodiak.unify.com (Dave Glende) sequent!sawmill!mdbs!kbc@cse.ogi.edu (Kevin Castleberry) -- Peter Mielke peter@doe.utoronto.ca Dictionary of Old English Project utgpu!utzoo!utdoe!peter University of Toronto
dmg@Unify.Com (Dave Glende) (01/25/91)
In article <1991Jan23.212828.28675@doe.utoronto.ca> peter@doe.utoronto.ca (Peter Mielke) writes: > >A few days i wrote: >> >> I'm looking for a relational database system that support fields of >> variable length text. What sort of systems are there available and >> what sort of hard limits are there to the text length? > >Well here is a summary of the replies i got: > > Name Maximum size of variable length field > > Progress 32K > Sybase 2147K > Informix 2 gigabytes > Spires ? > Oracle 64K > Unify ? Sorry if I wasn't clear. TEXT and BINARY fields in UNIFY can be up to ~2 GB in length. > KnowledgMan, 3.0 ? > Empress 2147K (the maximum value of int on the machine) > . . [text deleted] . . -- David Glende Work:(916) 920-9092 | Unify Corporation dmg@unify.com FAX :(916) 921-5340 | 3870 Rosin Court | Sacto, CA 95834