<title>Notes</title>
<para>
- <command>COPY TO</command> can be used only with plain
- tables, not views, and does not copy rows from child tables
- or child partitions. For example, <literal>COPY <replaceable
- class="parameter">table</replaceable> TO</literal> copies
- the same rows as <literal>SELECT * FROM ONLY <replaceable
- class="parameter">table</replaceable></literal>.
- The syntax <literal>COPY (SELECT * FROM <replaceable
- class="parameter">table</replaceable>) TO ...</literal> can be used to
- dump all of the rows in an inheritance hierarchy, partitioned table,
- or view.
+ <command>COPY TO</command> can be used with plain
+ tables and populated materialized views.
+ For example,
+ <literal>COPY <replaceable class="parameter">table</replaceable>
+ TO</literal> copies the same rows as
+ <literal>SELECT * FROM ONLY <replaceable class="parameter">table</replaceable></literal>.
+ However it doesn't directly support other relation types,
+ such as partitioned tables, inheritance child tables, or views.
+ To copy all rows from such relations, use <literal>COPY (SELECT * FROM
+ <replaceable class="parameter">table</replaceable>) TO</literal>.
</para>
<para>
RelationGetRelationName(rel)),
errhint("Try the COPY (SELECT ...) TO variant.")));
else if (rel->rd_rel->relkind == RELKIND_MATVIEW)
- ereport(ERROR,
- (errcode(ERRCODE_WRONG_OBJECT_TYPE),
- errmsg("cannot copy from materialized view \"%s\"",
- RelationGetRelationName(rel)),
- errhint("Try the COPY (SELECT ...) TO variant.")));
+ {
+ if (!RelationIsPopulated(rel))
+ ereport(ERROR,
+ errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot copy from unpopulated materialized view \"%s\"",
+ RelationGetRelationName(rel)),
+ errhint("Use the REFRESH MATERIALIZED VIEW command."));
+ }
else if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
copy copytest_foreign_table from stdin (freeze);
ERROR: cannot perform COPY FREEZE on a foreign table
rollback;
+-- Tests for COPY TO with materialized views.
+-- COPY TO should fail for an unpopulated materialized view
+-- but succeed for a populated one.
+CREATE MATERIALIZED VIEW copytest_mv AS SELECT 1 AS id WITH NO DATA;
+COPY copytest_mv(id) TO stdout WITH (header);
+ERROR: cannot copy from unpopulated materialized view "copytest_mv"
+HINT: Use the REFRESH MATERIALIZED VIEW command.
+REFRESH MATERIALIZED VIEW copytest_mv;
+COPY copytest_mv(id) TO stdout WITH (header);
+id
+1
+DROP MATERIALIZED VIEW copytest_mv;
1
\.
rollback;
+
+-- Tests for COPY TO with materialized views.
+-- COPY TO should fail for an unpopulated materialized view
+-- but succeed for a populated one.
+CREATE MATERIALIZED VIEW copytest_mv AS SELECT 1 AS id WITH NO DATA;
+COPY copytest_mv(id) TO stdout WITH (header);
+REFRESH MATERIALIZED VIEW copytest_mv;
+COPY copytest_mv(id) TO stdout WITH (header);
+DROP MATERIALIZED VIEW copytest_mv;