Обсуждение: postgres limitation
Hi, Is there any document about the limitation of postgres like the total size of one table the max row number of a table the max size of a row... Thanks Feng
On Fri, 26 Jan 2001, a wrote:
> Hi,
>
> Is there any document about the limitation of postgres
> like the total size of one table
none that we are aware of ...
> the max row number of a table
2^32 ... limitation is the OID size, which is currently a 32bit int ...
move to 64bit int's, and then your max row number is 2^64 :)
> the max size of a row...
8k in pre v7.1, no limit in v7.1 an dlater ...
>
> Thanks
> Feng
>
>
>
Marc G. Fournier ICQ#7615664 IRC Nick: Scrappy
Systems Administrator @ hub.org
primary: scrappy@hub.org secondary: scrappy@{freebsd|postgresql}.org
> > the max size of a row... > > 8k in pre v7.1, no limit in v7.1 an dlater ... 32k really... BLCKSZ can be changed.. I've had no trouble running a production database with BLCKSZ set to 32k though there might be issues I'm not aware of.. -Mitch
I've been following this thread but it's not clear to me what an 8k row limit means exactly. Does it mean that the size of all the data in that row must not be greater than 8k? That seems very small to me. Also, how does one change BLCKSZ? Some more detail on the subject would be great. thank you. Matt Friedman ----- Original Message ----- From: "Mitch Vincent" <mitch@venux.net> To: <pgsql-general@postgresql.org> Sent: Friday, January 26, 2001 7:28 PM Subject: Re: postgres limitation > > > the max size of a row... > > > > 8k in pre v7.1, no limit in v7.1 an dlater ... > > 32k really... BLCKSZ can be changed.. I've had no trouble running a > production database with BLCKSZ set to 32k though there might be issues I'm > not aware of.. > > -Mitch > > >
In your src/include directory of the PostgreSQL tree (pre 7.1 of course) -- edit config.h (after you run configure or config.h.in before) and look for the line(s) : /* * Size of a disk block --- currently, this limits the size of a tuple. * You can set it bigger if you need bigger tuples. */ /* currently must be <= 32k bjm */ #define BLCKSZ 32768 There I have mine to 32k, the upper limit. Change it, save it, recompile PG, you will have to initdb and import all your data too.. Viola! Remember. Just because I haven't had any problems doesn't mena you won't. Check the mailing list archives, I there was a thread on the possible dangers of BLCKSZ. Depending on what you're doing, you might want to check out 7.1 Beta (4 is the latest I think), I've been running various beta versions for a month (not in production) but it seems pretty stable and there is no limit on tuple size :-) -Mitch ----- Original Message ----- From: "Matt Friedman" <matt@daart.ca> To: "Mitch Vincent" <mitch@venux.net>; <pgsql-general@postgresql.org> Sent: Friday, January 26, 2001 11:32 PM Subject: Re: postgres limitation -what does it mean? (8k row limit) > I've been following this thread but it's not clear to me what an 8k row > limit means exactly. > > Does it mean that the size of all the data in that row must not be greater > than 8k? That seems very small to me. > > Also, how does one change BLCKSZ? > > Some more detail on the subject would be great. thank you. > > Matt Friedman > > > > > ----- Original Message ----- > From: "Mitch Vincent" <mitch@venux.net> > To: <pgsql-general@postgresql.org> > Sent: Friday, January 26, 2001 7:28 PM > Subject: Re: postgres limitation > > > > > > the max size of a row... > > > > > > 8k in pre v7.1, no limit in v7.1 an dlater ... > > > > 32k really... BLCKSZ can be changed.. I've had no trouble running a > > production database with BLCKSZ set to 32k though there might be issues > I'm > > not aware of.. > > > > -Mitch > > > > > > > >
Thanks for the info on how to alter the BLCKSZ. Sorry, but I'm still not 100 percent clear on what the limit effects. My assumption is that all of the data within one tuple or row must not exceed a size of 8k, provided that BLCKSZ is set to 8k. However, this doesn't seem right to me. What specifically is the meaning of the 8k limit? Matt Friedman Spry New Media http://www.sprynewmedia.com Lead Programmer/Partner email: matt@sprynewmedia.com phone: 250 744 3655 fax: 250 370 0436 ----- Original Message ----- From: "Mitch Vincent" <mitch@venux.net> To: "Matt Friedman" <matt@sprynewmedia.com>; <pgsql-general@postgresql.org> Sent: Saturday, January 27, 2001 9:01 AM Subject: Re: postgres limitation -what does it mean? (8k row limit) > In your src/include directory of the PostgreSQL tree (pre 7.1 of course) -- > edit config.h (after you run configure or config.h.in before) and look for > the line(s) : > > /* > * Size of a disk block --- currently, this limits the size of a tuple. > * You can set it bigger if you need bigger tuples. > */ > /* currently must be <= 32k bjm */ > #define BLCKSZ 32768 > > There I have mine to 32k, the upper limit. > > Change it, save it, recompile PG, you will have to initdb and import all > your data too.. > > Viola! > > Remember. Just because I haven't had any problems doesn't mena you won't. > Check the mailing list archives, I there was a thread on the possible > dangers of BLCKSZ. > > Depending on what you're doing, you might want to check out 7.1 Beta (4 is > the latest I think), I've been running various beta versions for a month > (not in production) but it seems pretty stable and there is no limit on > tuple size :-) > > -Mitch > > ----- Original Message ----- > From: "Matt Friedman" <matt@daart.ca> > To: "Mitch Vincent" <mitch@venux.net>; <pgsql-general@postgresql.org> > Sent: Friday, January 26, 2001 11:32 PM > Subject: Re: postgres limitation -what does it mean? (8k row limit) > > > > I've been following this thread but it's not clear to me what an 8k row > > limit means exactly. > > > > Does it mean that the size of all the data in that row must not be greater > > than 8k? That seems very small to me. > > > > Also, how does one change BLCKSZ? > > > > Some more detail on the subject would be great. thank you. > > > > Matt Friedman > > > > > > > > > > ----- Original Message ----- > > From: "Mitch Vincent" <mitch@venux.net> > > To: <pgsql-general@postgresql.org> > > Sent: Friday, January 26, 2001 7:28 PM > > Subject: Re: postgres limitation > > > > > > > > > the max size of a row... > > > > > > > > 8k in pre v7.1, no limit in v7.1 an dlater ... > > > > > > 32k really... BLCKSZ can be changed.. I've had no trouble running a > > > production database with BLCKSZ set to 32k though there might be issues > > I'm > > > not aware of.. > > > > > > -Mitch > > > > > > > > > > > > > > > >
Matt Friedman wrote: > Sorry, but I'm still not 100 percent clear on what the limit effects. My > assumption is that all of the data within one tuple or row must not exceed a > size of 8k, provided that BLCKSZ is set to 8k. > However, this doesn't seem right to me. What specifically is the meaning of > the 8k limit? Your assumption is correct. Pre-7.1, that is. -- Lamar Owen WGCR Internet Radio 1 Peter 4:11
Yepp, there is, but they are not all as open about it as postgres. Just browse
and search vendors such as mysql, mssql and oracle, and you will find that
they all have one limitation or another.
regards,
robert
In article <95d2dn$149m$1@news.tht.net>,
"<No Name>" <bobmarley4u2c@yahoo.com> writes:
> Are there limitations for other DBMS vendors? I would like to see that!
>
> robertg@juggler.kalmar.nsgroup.net wrote in message
> <95bv3v$tki$1@news.tht.net>...
>>In article <94skg9$n5q$1@news.tht.net>,
>> "a" <hong@cs.purdue.edu> writes:
>>> Hi,
>>>
>>> Is there any document about the limitation of postgres
>>> like the total size of one table
>>> the max row number of a table
>>> the max size of a row...
>>>
>>> Thanks
>>> Feng
>>>
>>>
>>
>>Limitations are listed at:
>>http://www.postgresql.org/users-lounge/limitations.html
>>
>>regards
>>robert gravsjo
>>
>>--
>> Robert Gravsjö robert.gravsjo@nsgroup.net
>> System developer Cell: +46 (0)708 72 00 46
>> Work: +46 (0)480 42 46 16
>> NS Group www.nsgroup.net
>
>
--
Robert Gravsjö robert.gravsjo@nsgroup.net
System developer Cell: +46 (0)708 72 00 46
Work: +46 (0)480 42 46 16
NS Group www.nsgroup.net
Are there limitations for other DBMS vendors? I would like to see that! robertg@juggler.kalmar.nsgroup.net wrote in message <95bv3v$tki$1@news.tht.net>... >In article <94skg9$n5q$1@news.tht.net>, > "a" <hong@cs.purdue.edu> writes: >> Hi, >> >> Is there any document about the limitation of postgres >> like the total size of one table >> the max row number of a table >> the max size of a row... >> >> Thanks >> Feng >> >> > >Limitations are listed at: >http://www.postgresql.org/users-lounge/limitations.html > >regards >robert gravsjo > >-- > Robert Gravsj� robert.gravsjo@nsgroup.net > System developer Cell: +46 (0)708 72 00 46 > Work: +46 (0)480 42 46 16 > NS Group www.nsgroup.net
In article <94skg9$n5q$1@news.tht.net>,
"a" <hong@cs.purdue.edu> writes:
> Hi,
>
> Is there any document about the limitation of postgres
> like the total size of one table
> the max row number of a table
> the max size of a row...
>
> Thanks
> Feng
>
>
Limitations are listed at:
http://www.postgresql.org/users-lounge/limitations.html
regards
robert gravsjo
--
Robert Gravsjö robert.gravsjo@nsgroup.net
System developer Cell: +46 (0)708 72 00 46
Work: +46 (0)480 42 46 16
NS Group www.nsgroup.net