Re: migration between databases and versions

> I would like to upgrade it to the newest version of postgres.
> 1) Is there a version for redhat 7.3.

Yes. You can run postgresql 7.2.x, 7.3.x & 7.4 on redhat 7.3.

> 2) How stable is postgres 7.4 ?

7.4 is stable. If i am in your position, i would rather wait for 7.4.3
or 7.4.4 for that matter.

> Eg: Old database with data
> has a Table named 'person' with fields A,B
> New Database to be put under prodcution
> also has an Table named 'person' with field A, B,C

If you are *very* sure that,

1) Columns are added, but not deleted
2) Tables are added, but not deleted
3) Tables are not renamed

then, you can follow the below steps to address your need:

1) IMPORTANT: Dump production database (schema & data). It is for safety
reason.
2) Dump production database (data only, using -a & -D option). Refer the
man page for the significance of -a & -D option.
3) Dump development database (schema only)
4) Restore development database (schema only)
5) Restore the dump which is taken in step 2 (data only)

Hope it addresses your need.

regards,
bhuvaneswaran