diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/dblink.sgml | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/doc/src/sgml/dblink.sgml b/doc/src/sgml/dblink.sgml index 855495c54d5..72ca765be73 100644 --- a/doc/src/sgml/dblink.sgml +++ b/doc/src/sgml/dblink.sgml @@ -426,14 +426,6 @@ SELECT * <title>Notes</title> <para> - <function>dblink</> fetches the entire remote query result before - returning any of it to the local system. If the query is expected - to return a large number of rows, it's better to open it as a cursor - with <function>dblink_open</> and then fetch a manageable number - of rows at a time. - </para> - - <para> A convenient way to use <function>dblink</> with predetermined queries is to create a view. This allows the column type information to be buried in the view, @@ -1432,6 +1424,18 @@ dblink_get_result(text connname [, bool fail_on_error]) returns setof record sent, and one additional time to obtain an empty set result, before the connection can be used again. </para> + + <para> + When using <function>dblink_send_query</> and + <function>dblink_get_result</>, <application>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 <function>dblink_open</> and then fetch a + manageable number of rows at a time. Alternatively, use plain + <function>dblink()</>, which avoids memory bloat by spooling large result + sets to disk. + </para> </refsect1> <refsect1> |