Frequently Asked Questions (FAQ) for PostgreSQL
- Last updated: Tue Jun 11 06:36:10 EDT 2002
+ Last updated: Thu Jun 20 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.
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Operational Questions