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Showing posts from February, 2013

pg_xlog_location_diff function for PostgreSQL/PPAS

In PostgreSQL 9.2, community has added a function pg_xlog_location_diff(), which is very useful for finding the difference between two xlog location in bytes and also useful for monitoring replication. Detail of this function is given in following link: http://www.postgresql.org/docs/9.2/static/functions-admin.html#FUNCTIONS-ADMIN-BACKUP However this function is not available for users of PostgreSQL/PPAS 9.0/9.1 users. So, I thought to write same function plpgsql so, that users can take benefit of same in 9.0/9.1. Before using formula and developing function, lets understand what is xlog and offset. Let's consider user has used function pg_current_xlog_location() function and he gets following information: worktest=# select pg_current_xlog_location(); pg_current_xlog_location -------------------------- 1/D1012B80 (1 row) In above, first field before forward slash is the hexadecimal value of logical xlog file and second field i.e. D1012B80 is hexadecimal offset inside