Download pgpool-II user manual

same, the group which includes master DB node (a DB node having the youngest node id) is remained and
other groups are degenerated.
If set to false, the session is terminated and the backends are not degenerated. Default is false.
white_function_list V3.0 Specify a comma separated list of function names that do not update the database. SELECTs using functions
not specified in this list are neither load balanced, nor replicated if in replication mode. In master slave
mode, such SELECTs are sent to master (primary) only.
You can use regular expression into the list to match function name (to which added automatically ^ and $),
for example if you have prefixed all your read only function with 'get_' or 'select_'
white_function_list = 'get_.*,select_.*'
black_function_list V3.0 Specify a comma separated list of function names that do update the database. SELECTs using functions
specified in this list are neither load balanced, nor replicated if in replication mode. In master slave mode,
such SELECTs are sent to master(primary) only.
You can use regular expression into the list to match function name (to which added automatically ^ and $)
for example if you have prefixed all your updating functions with 'set_', 'update_', 'delete_' or 'insert_':
black_function_list = 'nextval,setval,set_.*,update_.*,delete_.*,insert_.*'
Only one of these two lists can be filled in a configuration.
Prior to pgpool-II 3.0, nextval() and setval() were known to do writes to the database. You can emulate this
by using white_function_list and black_function_list:
white_function_list = ''
black_function_list = 'nextval,setval,lastval,currval'
Please note that we have lastval and currval in addition to nextval and setval. Though lastval() and currval()
are not writing functions, it is wise to add lastval() and currval() to avoid errors in the case when these
functions are accidentally load balanced to other DB node. Because adding to black_function_list will prevent
load balancing.
replicate_select
When set to true, pgpool-II replicates SELECTs in replication mode. If false, pgpool-II only sends them to the
Master DB. Default is false.
If a SELECT query is inside an explicit transaction block, replicate_select and load_balance_mode will have
an effect on how replication works. Details are shown below.