Ron <[hidden email]> writes:
> What does it mean, and where is it documented?
age(xid) returns the difference between the given xid and the current xid.
It's not terribly well documented, but psql's \df gives some info:
regression=# \df+ age
Schema | Name | Result data type | Argument data types | Type | Volatility | Parallel | Owner | Security | Access privileges | Language | Source code | Description
pg_catalog | age | integer | xid | func | stable | restricted | postgres | invoker | | internal | xid_age | age of a transaction ID, in transactions before current transaction
The only reference I could find in the SGML docs is in the maintenance