Re: BUG #8400: DB size changed after restore

"ajayaksadvance@gmail.com" <ajayaksadvance@gmail.com> wrote:=0A=0A> Postgre=
SQL version: 9.2.0=0A=0AThere have been many fixes for bugs and security vu=
lnerabilities in=0Athe 9.2 minor releases since 9.2.0.=0A=0Ahttp://www.post=
gresql.org/support/versioning/=0A=0A> I am not sure its a bug or not but ne=
ed some information on this.=0A=0AThere's no real evidence of a bug, it wou=
ld have been better to=0Apost a question to: pgsql-general@postgresql.org=
=0A=0A> I am doing upgrade from 8.4 to 9.2 hence DB dump and then=0A> resto=
re.=0A=0ANormally when upgrading with this technique you should use the=0Ap=
g_dump executable from the target version to dump the old=0Adatabase.=A0 Th=
e newer software understands previous storage formats,=0Abut the older soft=
ware doesn't know anything about versions that=0Awere written later.=0A=0A>=
 On postgrse 8.4 , i have DB of size 32 GB.=0A> SELECT pg_size_pretty(pg_da=
tabase_size('<DBNAME>'))=0A>=A0=A0 As fulldbsize;=0A>=0A> I have done vacum=
mdb before going for dump.=0A=0AThat will make space available for re-use, =
but generally won't=0Aeliminate dead space or reduce file sizes.=0A=0A> I h=
ave first done schema dump and then DB data and all is fine.=0A>=0A> But on=
 restore its running successfully but i am getting only=0A> size 9213 MB.=
=0A>=0A> Dont know, what exactly happend?=0A=0AWell, you could narrow the p=
ossibilities by restoring that dump to=0Aan 8.4 database and see how big th=
at is.=A0 Some major releases have=0Aimproved the storage formats for some =
data types, like numeric; but=0Ayou might just be dealing with dead space f=
rom deletes and updates.=0A=0A--=0AKevin Grittner=0AEDB: http://www.enterpr=
isedb.com=0AThe Enterprise PostgreSQL Company