| 2 postmaster.opts | 3 pg_notify | 4 postgresql.conf | 5 pg_tblspc | 6 logfile | 7 base | 8 postmaster.pid | 9 pg_ident.conf | 10 global | Otherwise it is the time when the postmaster process re-read the configuration files.) pg_current_logfile returns, as text, the path of the log file(s) currently in use by the logging collector. The path the return value is NULL. When multiple log files exist, each in a different format, pg_cur- rent_logfile called without arguments returns the path of the file having the first format found in the ordered

估值计算，HLL代替count(distinct xx) • 频繁更新的字段与不频繁更新的字段建议拆成多个表， 提高更新效率。 • 业务层避免死锁 • 根据业务需求调整表级autovacuum相关参数 • 内存足够时，UDF中尽量使用数组代替临时表 • JOIN的固化、子查询的固化。（plan hint OR query写法 +patameter） • GIN 索引 UPDATE 加速

pg_logical_slot_get_changes • 返回槽slot_name中的改变，从上一次已经被消费的点开始返回。 pg_logical_slot_peek_changes • 参数和行为就像pg_logical_slot_get_changes()函数，不过改变不会被 消费，即在未来的调用中还会返回这些改变。 2016Postgres中国用户大会 Postgres

| 2 postmaster.opts | 3 pg_notify | 4 postgresql.conf | 5 pg_tblspc | 6 logfile | 7 base | 8 postmaster.pid | 9 pg_ident.conf | 10 global | Otherwise it is the time when the postmaster process re-read the configuration files.) pg_current_logfile returns, as text, the path of the log file(s) currently in use by the logging collector. The path the return value is NULL. When multiple log files exist, each in a different format, pg_current_logfile called without arguments returns the path of the file having the first format 310 Functions and

pg_reload_conf() boolean Cause server processes to reload their configuration files pg_rotate_logfile() boolean Rotate server’s log file Each of these functions returns true if successful and false to the server, causing the configuration files to be reloaded by all server processes. pg_rotate_logfile signals the log-file manager to switch to a new output file immediately. This works only when the /usr/local/pgsql/bin/initdb -D /usr/local/pgsql/data /usr/local/pgsql/bin/postgres -D /usr/local/pgsql/data >logfile 2>&1 & /usr/local/pgsql/bin/createdb test /usr/local/pgsql/bin/psql test The long version is the

pg_reload_conf() boolean Cause server processes to reload their configuration files pg_rotate_logfile() boolean Rotate server’s log file Each of these functions returns true if successful and false to the server, causing the configuration files to be reloaded by all server processes. pg_rotate_logfile signals the log-file manager to switch to a new output file immediately. This works only when the /usr/local/pgsql/bin/initdb -D /usr/local/pgsql/data /usr/local/pgsql/bin/postgres -D /usr/local/pgsql/data >logfile 2>&1 & /usr/local/pgsql/bin/createdb test /usr/local/pgsql/bin/psql test The long version is the

pg_reload_conf() boolean Cause server processes to reload their configuration files pg_rotate_logfile() boolean Rotate server’s log file Each of these functions returns true if successful and false signal to the server, causing configuration files to be reloaded by all server processes. pg_rotate_logfile signals the log-file manager to switch to a new output file immediately. This works only when the /usr/local/pgsql/bin/initdb -D /usr/local/pgsql/data /usr/local/pgsql/bin/postgres -D /usr/local/pgsql/data >logfile 2>&1 & /usr/local/pgsql/bin/createdb test /usr/local/pgsql/bin/psql test The long version is the

pg_reload_conf() boolean Cause server processes to reload their configuration files pg_rotate_logfile() boolean Rotate server’s log file Each of these functions returns true if successful and false signal to the server, causing configuration files to be reloaded by all server processes. pg_rotate_logfile signals the log-file manager to switch to a new output file immediately. This works only when the /usr/local/pgsql/bin/initdb -D /usr/local/pgsql/data /usr/local/pgsql/bin/postgres -D /usr/local/pgsql/data >logfile 2>&1 & /usr/local/pgsql/bin/createdb test /usr/local/pgsql/bin/psql test The long version is the

pg_reload_conf() boolean Cause server processes to reload their configuration files pg_rotate_logfile() boolean Rotate server’s log file Each of these functions returns true if successful and false the postmaster, causing the configuration files to be reloaded by all server processes. pg_rotate_logfile signals the log-file manager to switch to a new output file immediately. This works only when redirect_stderr /usr/local/pgsql/bin/initdb -D /usr/local/pgsql/data /usr/local/pgsql/bin/postmaster -D /usr/local/pgsql/data > logfile 2> &1 & /usr/local/pgsql/bin/createdb test /usr/local/pgsql/bin/psql test The long version is the

| 2 postmaster.opts | 3 pg_notify | 4 postgresql.conf | 5 pg_tblspc | 6 logfile | 7 base | 8 postmaster.pid | 9 pg_ident.conf | 10 global | Otherwise it is the time when the postmaster process re-read the configuration files.) pg_current_logfile returns, as text, the path of the log file(s) currently in use by the logging collector. The path the return value is NULL. When multiple log files exist, each in a different format, pg_current_logfile called without arguments returns the path of the file having the first format found in the ordered