Re: line datatype - Mailing list pgsql-sql

From Bruce Momjian
Subject Re: line datatype
Date
Msg-id 200207151443.g6FEh6E28810@candle.pha.pa.us
Whole thread Raw
In response to line datatype  (Tim Hart <tjhart@mac.com>)
List pgsql-sql
Tim Hart wrote:
> Probably the most succinct explanation would be to copy & paste from the 
> terminal...
> 
> tjhart=> create table a_line( foo line );
> CREATE
> tjhart=> insert into a_line ( foo ) values( '(0,0), (1,1)' );
> ERROR:  line not yet implemented
> tjhart=> select version();
>                                 version
> ---------------------------------------------------------------------
>   PostgreSQL 7.2.1 on powerpc-apple-darwin5.3, compiled by GCC 2.95.2
> (1 row)
> 
> 
> The documentation (datatype-geometric.html) indicates both a 'line' type 
> and an 'lseg' type in the summary table at the top of the page. The same 
> code above using the type 'lseg' in place of 'line' works just fine.
> 
> Why can I create a table with a column of type 'line' if I can't insert 
> into it?

Well, that's a very good question.  I see you have to compile PostgreSQL
with ENABLE_LINE_TYPE defined in pg_config.h.in  and rerun configure.

I see this commit from August 16, 1998:revision 1.35date: 1998/08/16 04:06:55;  author: thomas;  state: Exp;  lines: +7
-6Disablenot-ready-to-use support code for the line data type.Bracket things with #ifdef ENABLE_LINE_TYPE.The line data
typehas always been used internally to support other types, but I/O routines have never been defined for it.
 

psql \dT clearly shows line and lseg:
line                        | geometric line '(pt1,pt2)'lseg                        | geometric line segment
'(pt1,pt2)'

so I think we have both a documentation problem, psql problem, and code
problem.  Let's see what Thomas says.

For the short term, I would use lseg because it looks the same.

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
853-3000+  If your life is a hard drive,     |  830 Blythe Avenue +  Christ can be your backup.        |  Drexel Hill,
Pennsylvania19026
 


pgsql-sql by date:

Previous
From: "Julian Scarfe"
Date:
Subject: Re: Indexes with LIKE
Next
From: Jie Liang
Date:
Subject: Re: pg_restore cannot restore index