Fix documentation of "must be vacuumed within" warning.

Warnings start 10M transactions before xidStopLimit, which is 11M
transactions before wraparound.  The sample WARNING output showed a
value greater than 11M, and its HINT message predated commit
25ec228ef7.  Hence, the sample was
impossible.  Back-patch to 9.5 (all supported versions).
This commit is contained in:
Noah Misch 2020-06-27 22:05:04 -07:00
parent e1cc25f59a
commit 96879a0efb
1 changed files with 5 additions and 6 deletions

View File

@ -606,14 +606,13 @@ SELECT datname, age(datfrozenxid) FROM pg_database;
</para>
<para>
If for some reason autovacuum fails to clear old XIDs from a table,
the system will begin to emit warning messages like this when the
database's oldest XIDs reach ten million transactions from the wraparound
point:
If for some reason autovacuum fails to clear old XIDs from a table, the
system will begin to emit warning messages like this when the database's
oldest XIDs reach eleven million transactions from the wraparound point:
<programlisting>
WARNING: database "mydb" must be vacuumed within 177009986 transactions
HINT: To avoid a database shutdown, execute a database-wide VACUUM in "mydb".
WARNING: database "mydb" must be vacuumed within 10985967 transactions
HINT: To avoid a database shutdown, execute a database-wide VACUUM in that database.
</programlisting>
(A manual <command>VACUUM</command> should fix the problem, as suggested by the