Thread

1. Re: Boolean and Bit

   Josh Berkus <josh@agliodbs.com> — 2001-01-17T06:01:00Z

   Keith,
   
   > This is a compatibility issue. While I prefer to use
   > BOOLEAN, this is SQL3
   > and not available on the (unfortunately must use)
   > MS-SQL/MSDE platform.
   > 
   > My options are to use a CHAR field and re-write my code
   > for "T" and "F" or
   > an int field and re-write my code to use "field=0" and
   > "field<>0"
   
   Given that all the MS-SQL BIT field is, is INT1, using INT2
   should not be much of a problem.  Go ahead an create a
   custom type based on INT2 and add constraints to prevent any
   values outside of the range of 0 and 1.
   
   This is where the SQL92 DOMAIN (not, as far as I know,
   available in PGSQL) construction would be useful in
   PostgreSQL instead of TYPE (Tom?).  The problem with TYPE is
   that you theoretically need to define a whole set of
   operators for your TYPE, while DOMAIN is a bit simpler.
   
   > I would like to distribute a script (SQL) file to our
   > users to update
   > databases to new versions... obstacles include
   > BOOLEAN/BIT and the 
   > inconsistent use of BLOB/MEMO/[long]varchar(4096).
   
   Well, yes.  This is beacause BLOBs are NOT part of the SQL
   standard and IMHO a bad idea relationally; thus their
   implementation is entirely proprietary to the RDBMS.  The
   solution is not to use BLOBs.  
   
   > Distributing schema patches is proving troublesome across
   > multiple
   > platforms.
   
   Yup.  Yer in for a world of pain, sonny.  Hope you get paid
   hourly.
   
   -Josh
   
   

2. Re: Re: Boolean and Bit

   Josh Berkus <josh@agliodbs.com> — 2001-01-17T16:36:21Z

   Josh Berkus wrote:
   
   > Well, yes.  This is beacause BLOBs are NOT part of the SQL
   > standard and IMHO a bad idea relationally; thus their
   > implementation is entirely proprietary to the RDBMS.  The
   > solution is not to use BLOBs.
   
   Ooops.  Let me re-state:  This is because the *implementation* of BLOBS
   is not defined in the SQL standard, and BLOBs are IMHO a bad idea for
   relational database design, as they violate Codd's Rules.  Thus the
   implementation of, anf functions and operators for BLOBs are entirely
   proprietary to the RDBMS platform.
   
   The solution to this is not to use BLOBs, but rather to use file system
   handles for the location of the binary data on the server.  This way,
   all you need is DOS-to-UNIX and UNIX-to-DOS translation for the
   filesystem handles, something easily accomplished through
   string-manipulation functions or stored procedures.
   
   					-Josh Berkus
   
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3. Re: Boolean and Bit

   Keith Gray <keith@heart.com.au> — 2001-01-17T22:51:59Z

   Josh Berkus wrote:
   > 
   > 
   > The solution to this is not to use BLOBs, but rather to use file system
   > handles for the location of the binary data on the server.  This way,
   > all you need is DOS-to-UNIX and UNIX-to-DOS translation for the
   > filesystem handles, something easily accomplished through
   > string-manipulation functions or stored procedures.
   > 
   >                                         -Josh Berkus
   
   
   Do you have an example for implementing this?