dblink_get_result — gets an async query result
dblink_get_result(text connname [, bool fail_on_error]) returns setof record
dblink_get_result collects the results of an asynchronous query previously sent with
dblink_send_query. If the query is not already completed,
dblink_get_result will wait until it is.
Name of the connection to use.
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 returns no rows.
# Return Value
For an async query (that is, an SQL statement returning rows), the function returns the row(s) produced by the query. To use this function, you will need to specify the expected set of columns, as previously discussed for
For an async command (that is, an SQL statement not returning rows), the function returns a single row with a single text column containing the command's status string. It is still necessary to specify that the result will have a single text column in the calling
This function must be called if
dblink_send_query returned 1. It must be called once for each query sent, and one additional time to obtain an empty set result, before the connection can be used again.
dblink_get_result, dblink fetches the entire remote query result before returning any of it to the local query processor. If the query returns a large number of rows, this can result in transient memory bloat in the local session. It may be better to open such a query as a cursor with
dblink_open and then fetch a manageable number of rows at a time. Alternatively, use plain
dblink(), which avoids memory bloat by spooling large result sets to disk.
contrib_regression=# SELECT dblink_connect('dtest1', 'dbname=contrib_regression'); dblink_connect