Re: postgres limitation - Mailing list pgsql-admin

How about the full answer?  I think Tom did a fantastic job of writing up,
be a shame to make it go to waste for brevity? :(

On Sat, 27 Jan 2001, Bruce Momjian wrote:

> OK, how is this?
>
>
> These are the limits:
>
>     Maximum size for a database?             unlimited (60GB databases exist)
>     Maximum size for a table?                64 TB on all operating systems
>     Maximum size for a row?                  unlimited in 7.1 and later
>     Maximum size for a field?                1GB in 7.1 and later
>     Maximum number of rows in a table?       unlimited
>     Maximum number of columns in a table?    1600
>     Maximum number of indexes on a table?    unlimited
>
>     Of course, these are not actually unlimited, but limited to
>     available disk space and memory/swap space.  Performance may
>     suffer when these values get unusually large.
>
> ---------------------------------------------------------------------------
>
>
>
> > Bruce, I think section 4.6 of the FAQ is a tad on the short and overly
> > optimistic side.  Here's a set of more precise statements ...
> >
> >
> >     4.6) What is the maximum size for a row, table, database?
> >
> > Maximum size for a database?
> >
> > Effectively unlimited, although you may see performance problems with
> > more than a few thousand tables in a database, depending on how
> > gracefully your filesystem copes with directories containing many files.
> >
> > Maximum size for a table?
> >
> > 2G blocks, hence 16 to 64 terabytes depending on the BLCKSZ
> > configuration constant.  (If someone were to run around and make sure
> > all the block-number arithmetic is unsigned, we could claim 4G blocks,
> > but I think it's not all unsigned now...)
> >
> > Maximum size for a row?
> >
> > See limits on field size and number of columns.
> >
> > Maximum size for an individual field value?
> >
> > Field values are limited to 1Gb, and in practice are more tightly
> > limited by memory/swap space available to a backend; a field value that
> > is a large fraction of the maximum process memory size will probably
> > cause out-of-memory failures.
> >
> > Maximum number of columns in a table?
> >
> > 1600.  In practice probably quite a bit less, even with TOAST, since the
> > master tuple still has to fit in a block.  If all the columns are large
> > (toastable) then at most you could fit about 250 columns with BLCKSZ=8K,
> > since an out-of-line TOAST value pointer takes 32 bytes.  On the other
> > hand, 1600 int4 columns would fit easily.
> >
> > Maximum number of rows in a table?
> >
> > No specific limit.  Note however that the COUNT() function currently
> > uses an int4 counter, so will give bogus results for more than 2G rows.
> >
> > Maximum number of indexes on a table?
> >
> > No limit.
> >
> >             regards, tom lane
> >
>
>
> --
>   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, Pennsylvania 19026
>

Marc G. Fournier                   ICQ#7615664               IRC Nick: Scrappy
Systems Administrator @ hub.org
primary: scrappy@hub.org           secondary: scrappy@{freebsd|postgresql}.org