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I updated some Cygwin packages and now I can't start Postgres:

$ /usr/sbin/postmaster
FATAL:  database files are incompatible with server
DETAIL:  The data directory was initialized by PostgreSQL version 8.2, which is not compatible with this version 9.2.4.

I tried pg_upgrade but you need to specify both the old and new binary. Plus, pg_upgrade says it only works with 8.3.

I thought I could use setup-x86.exe to pick the previous version, which is 8.2.11-1, however when I install that, then I can't start Postgres:

$ /usr/sbin/postgres.exe
Bad system call (core dumped)
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Hello my friend, we meet again. The data directory was initialized by PostgreSQL version 9.2, which is not compatible with this version 9.3.5. –  Chloe 15 mins ago

1 Answer 1

  1. Uninstall postgres 9
  2. Install postgres 8.2
  3. Install libpq
  4. /etc/rc.d/init.d/postgresql start
  5. Do this for each database:
    • pg_dump -f stocks.sql.gz -Z 9 -C stocks
  6. /etc/rc.d/init.d/postgresql stop
  7. cd $PGDATA/.. # /usr/share/postgresql/..
  8. mv postgresql postgresql-8.2
  9. Install postgres 9, postgresql-contrib, uninstall libpq.
  10. /usr/sbin/pg_ctl.exe init
  11. /usr/sbin/pg_ctl.exe start
  12. createdb.exe # Creates a DB with your username
  13. gzip -dc stocks.sql.gz | psql # many warnings + errors
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You left out one really important item -- Step Zero: Read the most excellent documentation. Your steps above are otherwise correct, though there shouldn't be "many warnings + errors" at step 13 -- the reload should go smoothly... –  voretaq7 Aug 20 '13 at 19:33
You could also use pg_dumpall instead of dumping individual databases -- might make your life easier. –  voretaq7 Aug 20 '13 at 19:34

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