Every replication account has an associated sequence which holds
replication account level (basically, transaction number). Each
subscriber also maintains a sequence where it stores its
replication account level.
When subscriber issues a sync request for an account it submits
its replication account level so publisher can find a point in time
from where it should start to submit replication logs to
Replication account level can roll over REPL_WRAPAROUND
(0x7fffffff) to 1. Old replication logs need to be purged to allow
this to work correctly. Procedure repl_purge() purges
replication logs for a specified account.
Columns needed to store purger configuration in
SYS_REPL_ACCOUNTS table are:
P_MONTH integer (month, nullable)
P_DAY integer (day of month, nullable)
P_TIME time (time, nullable)
If P_TIME is NULL log purger will not be scheduled to run at
all. If P_TIME is not NULL there can be the following combinations
of P_MONTH, P_DAY and P_WDAY ('*' means NULL value, 'x' means any
An entry to call purger is inserted (or updated) into
SYS_SCHEDULED_EVENT after each modification of purger settings for
an account (from Admin UI) or after each successful run of
repl_purge() for this account.