Size of tuples
I have a table whose definition is basically
create table foo (
a int,
b int,
c int,
d date
);
and when fully populated, select relpages*8192::long/reltuples from pg_class
where relname='foo';
gives around 52. Why is it so wide when there are only 4*4=16 bytes of
actual data?
The table was populated in one big go, and there have been 0 deletes or
updates, althought I did do a few truncates, but I thought that basically
zeroed everything?
Alex.
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On 10/09/06 19:10, Alex Turner wrote:
I have a table whose definition is basically
create table foo (
a int,
b int,
c int,
d date
);and when fully populated, select relpages*8192::long/reltuples from
pg_class
where relname='foo';
gives around 52. Why is it so wide when there are only 4*4=16 bytes of
actual data?
http://www.postgresql.org/docs/faqs.FAQ.html#item4.5
23 row header (no OIDs)
+ 16 your row size
+ 4 page pointer
--
43I'd guess that the extra 4 bytes is from the null bits, page
overhead, etc.
- --
Ron Johnson, Jr.
Jefferson LA USA
Is "common sense" really valid?
For example, it is "common sense" to white-power racists that
whites are superior to blacks, and that those with brown skins
are mud people.
However, that "common sense" is obviously wrong.
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Awesome - thank you!
Alex
Show quoted text
On 10/9/06, Ron Johnson <ron.l.johnson@cox.net> wrote:
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Hash: SHA1On 10/09/06 19:10, Alex Turner wrote:
I have a table whose definition is basically
create table foo (
a int,
b int,
c int,
d date
);and when fully populated, select relpages*8192::long/reltuples from
pg_class
where relname='foo';
gives around 52. Why is it so wide when there are only 4*4=16 bytes of
actual data?http://www.postgresql.org/docs/faqs.FAQ.html#item4.5
23 row header (no OIDs) + 16 your row size + 4 page pointer -- 43I'd guess that the extra 4 bytes is from the null bits, page
overhead, etc.- --
Ron Johnson, Jr.
Jefferson LA USAIs "common sense" really valid?
For example, it is "common sense" to white-power racists that
whites are superior to blacks, and that those with brown skins
are mud people.
However, that "common sense" is obviously wrong.
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vMEiTn+MTBeP6wEkLO3zdwI=
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TIP 4: Have you searched our list archives?
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You know, I'd have sworn that I changed "extra 4" to "extra 9"
Sorry.
On 10/10/06 12:49, Alex Turner wrote:
Awesome - thank you!
Alex
On 10/9/06, *Ron Johnson* <ron.l.johnson@cox.net
<mailto:ron.l.johnson@cox.net>> wrote:On 10/09/06 19:10, Alex Turner wrote:
I have a table whose definition is basically
create table foo (
a int,
b int,
c int,
d date
);and when fully populated, select relpages*8192::long/reltuples from
pg_class
where relname='foo';
gives around 52. Why is it so wide when there are only 4*4=16bytes of
actual data?
http://www.postgresql.org/docs/faqs.FAQ.html#item4.5
23 row header (no OIDs) + 16 your row size + 4 page pointer -- 43I'd guess that the extra 4 bytes is from the null bits, page
overhead, etc.
- --
Ron Johnson, Jr.
Jefferson LA USA
Is "common sense" really valid?
For example, it is "common sense" to white-power racists that
whites are superior to blacks, and that those with brown skins
are mud people.
However, that "common sense" is obviously wrong.
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