Frequently Asked Questions (FAQ) for PostgreSQL

Last updated:Tue Jun11 06:36:10 EDT 2002

Last updated:Thu Jun20 22:00:57 EDT 2002

Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us)

3.7) What debugging features are available?

3.8) Why do I get "Sorry, too many clients" when trying to connect?

3.9) What are the pg_sorttempNNN.NN files in my database directory?

3.10) Why do I need to do a dump and restore to upgrade PostgreSQL?

Operational Questions

The temporary files should be deleted automatically, but might not if

a backend crashes during a sort. If you have no backends running at

the time, it is safe to delete the pg_tempNNN.NN files.

3.10) Why do I need to do a dump and restore to upgrade PostgreSQL?

The PostgreSQL team tries very heard to maintain compatability across

minor releases. So upgrading from 7.2 to 7.2.1 does not require a dump

a restore. However, new features are continuously being adding and

sometimes this requires new fields to be added to system tables.

These changes may be across many tables and so maintaining backward

compatability would be quite difficult. Thus, restoring from a dump is

required to make everything work.

Note that the actual on-disk file format does not change very often, a

feature the pg_upgrade script uses quite successfully. There the dump

is used create the necessary information in the system tables. The

data files are then just copied across. This method is not as

guarenteed as the dump/restore method but when it works it can make

upgrades very efficient.

_________________________________________________________________

Operational Questions

alink="#0000ff">

<H1>Frequently Asked Questions (FAQ) for PostgreSQL</H1>

<P>Last updated:Tue Jun11 06:36:10 EDT 2002</P>

<P>Last updated:Thu Jun20 22:00:57 EDT 2002</P>

<P>Current maintainer: Bruce Momjian (<Ahref=

"mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</A>)<BR>