Bug #805: pg_dump examines all tables even with -t "table_name" speficied
Vitaliy Fuks (vitaliyfuks@yahoo.com) reports a bug with a severity of 3
The lower the number the more severe it is.
Short Description
pg_dump examines all tables even with -t "table_name" speficied
Long Description
Running pg_dump -t table_name -vv shows pg_dump examining every table in the database. With many tables present (in hundreds) this can make the process of dumping just one table take a considerable amount of time.
With pg_dump -t specified it should go straight for the requested table and then figure what other dependent objects need to be examined.
Happens on pg_dump 7.2.3 under Linux (RedHat RPM) and i386 Solaris.
Are there some technical limitations forcing pg_dump to read everything? If not it seems that the logic behind is just not optimal.
Sample Code
No file was uploaded with this report
pgsql-bugs@postgresql.org writes:
pg_dump examines all tables even with -t "table_name" speficied
7.3 is a little better. It's not that easy to determine in advance what
information is needed, though; consider inheritance for example.
regards, tom lane
Hello,
Could there potentially be an option in addition to -t "table_name", to
either:
a) Examine all relationships and dump all dependant objects
b) Dump only table named "table_name"
One can argue that when asking for "a" table one really only wants that
table information, and nothing else. Some people of course can argue
that just a table by itself may not be usable by itself in some
situations - so that's why the option described above could cater both
situations.
I wish I could just give you a patch but there are probably people who
know pg_dump internals who could produce such patch in 10x less amount
of time.
--Vitaliy
--- Tom Lane <tgl@sss.pgh.pa.us> wrote:pgsql-bugs@postgresql.org writes:
pg_dump examines all tables even with -t "table_name" speficied
7.3 is a little better. It's not that easy to determine in advance
what
information is needed, though; consider inheritance for example.regards, tom lane
__________________________________________________
Do you Yahoo!?
HotJobs - Search new jobs daily now
http://hotjobs.yahoo.com/
We are thinking of adding a per-schema dump option in 7.4. Would that
help?
---------------------------------------------------------------------------
Vitaliy Fuks wrote:
Hello,
Could there potentially be an option in addition to -t "table_name", to
either:a) Examine all relationships and dump all dependant objects
b) Dump only table named "table_name"One can argue that when asking for "a" table one really only wants that
table information, and nothing else. Some people of course can argue
that just a table by itself may not be usable by itself in some
situations - so that's why the option described above could cater both
situations.I wish I could just give you a patch but there are probably people who
know pg_dump internals who could produce such patch in 10x less amount
of time.--Vitaliy
--- Tom Lane <tgl@sss.pgh.pa.us> wrote:pgsql-bugs@postgresql.org writes:
pg_dump examines all tables even with -t "table_name" speficied
7.3 is a little better. It's not that easy to determine in advance
what
information is needed, though; consider inheritance for example.regards, tom lane
__________________________________________________
Do you Yahoo!?
HotJobs - Search new jobs daily now
http://hotjobs.yahoo.com/---------------------------(end of broadcast)---------------------------
TIP 4: Don't 'kill -9' the postmaster
--
Bruce Momjian | http://candle.pha.pa.us
pgman@candle.pha.pa.us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073