dblink_exec — executes a command in a remote database
dblink_exec executes a command (that is, any SQL statement that doesn't return rows) in a remote database.
When two text arguments are given, the first one is first looked up as a persistent connection's name; if found, the command is executed on that connection. If not found, the first argument is treated as a connection info string as for dblink_connect, and the indicated connection is made just for the duration of this command.
connname
Name of the connection to use; omit this parameter to use the unnamed connection.
connstr
A connection info string, as previously described for dblink_connect.
sql
The SQL command that you wish to execute in the remote database, for example insert into foo values(0,'a','{"a0","b0","c0"}').
fail_on_error
If true (the default when omitted) then an error thrown on the remote side of the connection causes an error to also be thrown locally. If false, the remote error is locally reported as a NOTICE, and the function's return value is set to ERROR.
Returns status, either the command's status string or ERROR.