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Thread: 8Ko limitation

8Ko limitation

From
"Xavier ZIMMERMANN"
Date:


Hi,

I am thinking about using postgreSQL to manage large geographic databases
connected to a GIS.
I would really appreciate if someone could give me some answers to those 3
questions :
   what about performances with postgreSQL and large databases,
   the object size limitation (8192 bytes) is really not acceptable for this
   purpose. Is there a way or any hack to overpass it,
   is the geographic index working well.

Thanks.

Xavier.

Re: 8Ko limitation

From
Karel Zak
Date:
>    what about performances with postgreSQL and large databases,
>    the object size limitation (8192 bytes) is really not acceptable for this

 Now you can change this limit in config.h, the possible range is
8Kb - 32Kb.

 In new 7.1 version will this limit dead forever (see TOAST project).

 And what is a "large database"? 1, 5 .. 10Gb? If yes, (IMHO) the PostgreSQL
is good choice.

                    Karel

Re: 8Ko limitation

From
"Justin Hickey"
Date:
Hello Karel

On Jul 20, 10:00am, Karel Zak wrote:
> Subject: Re: [HACKERS] 8Ko limitation
>
> >    what about performances with postgreSQL and large databases,
> >    the object size limitation (8192 bytes) is really not acceptable for
this
>
>  Now you can change this limit in config.h, the possible range is
> 8Kb - 32Kb.
>
>  In new 7.1 version will this limit dead forever (see TOAST project).

We use Postgres to store polygons and I asked this same question before. The
reply I got was that the geometric data types were not guaranteed to be
converted to TOASTable data types (they were at the bottom of the list of types
to convert). They hinted that I could help them with this but I have no time.
Has this changed now? Will the geometric data types be TOASTable for 7.1?


-- 
Sincerely,

Jazzman (a.k.a. Justin Hickey)  e-mail: jhickey@hpcc.nectec.or.th
High Performance Computing Center
National Electronics and Computer Technology Center (NECTEC)
Bangkok, Thailand
==================================================================
People who think they know everything are very irritating to those
of us who do.  ---Anonymous

Jazz and Trek Rule!!!
==================================================================

Re: 8Ko limitation

From
Tom Lane
Date:
"Justin Hickey" <jhickey@impact1.hpcc.nectec.or.th> writes:
>  Will the geometric data types be TOASTable for 7.1?

Probably ... if I get around to it ... or someone else does
(yes, that's a hint).

            regards, tom lane

Re: 8Ko limitation

From
Hannu Krosing
Date:
Xavier ZIMMERMANN wrote:
>
> Hi,
>
> I am thinking about using postgreSQL to manage large geographic databases
> connected to a GIS.
...
>    is the geographic index working well.

AFAIK r-trees ar used for planar geometry.
perhaps there something in contrib for geographic (spherical)
coordinates.

--------
Hannu