ALTER SUBSCRIPTION / REFRESH docs: explain copy_data

The docs are ambiguous as to which tables would be copied over when the
copy_data parameter is true in ALTER SUBSCRIPTION ... REFRESH PUBLICATION.
Make it clear that it only applies to tables which are new in the
publication.

Author: David Christensen (reword by Álvaro Herrera)
Discussion: https://postgr.es/m/95339420-7F09-4F8C-ACC0-8F1CFAAD9CD7@endpoint.com

diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index 6dfb2e4d3e01743fbb6b1836247c3b0d0e48c0e5..1b8beadbaa543eb7b84609899220babd5188e0fe 100644 (file)
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -128,7 +128,8 @@ ALTER SUBSCRIPTION name RENAME TO <
          
           Specifies whether the existing data in the publications that are
           being subscribed to should be copied once the replication starts.
-          The default is true.
+          The default is true.  (Previously subscribed
+          tables are not copied.)