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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2021-11-29 12:13:13 -0500 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2021-11-29 12:13:13 -0500 |
| commit | a7359913a1c22e8c04f37140b9d983919baf10b2 (patch) | |
| tree | 2e8a4ca54361ad207762ad29075b9321d8a219a2 /doc | |
| parent | f76fd05bae047103cb36ef5fb82137c8995142c1 (diff) | |
| download | postgresql-a7359913a1c22e8c04f37140b9d983919baf10b2.tar.gz | |
Doc: improve documentation about ORDER BY in matviews.
Remove the confusing use of ORDER BY in an example materialized
view. It adds nothing to the example, but might encourage
people to follow bad practice. Clarify REFRESH MATERIALIZED
VIEW's note about whether view ordering is retained (it isn't).
Maciek Sakrejda
Discussion: https://postgr.es/m/CAOtHd0D-OvrUU0C=4hX28p4BaSE1XL78BAQ0VcDaLLt8tdUzsg@mail.gmail.com
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/src/sgml/ref/refresh_materialized_view.sgml | 10 | ||||
| -rw-r--r-- | doc/src/sgml/rules.sgml | 3 |
2 files changed, 4 insertions, 9 deletions
diff --git a/doc/src/sgml/ref/refresh_materialized_view.sgml b/doc/src/sgml/ref/refresh_materialized_view.sgml index 8ae62671ad..675d6090f3 100644 --- a/doc/src/sgml/ref/refresh_materialized_view.sgml +++ b/doc/src/sgml/ref/refresh_materialized_view.sgml @@ -93,12 +93,10 @@ REFRESH MATERIALIZED VIEW [ CONCURRENTLY ] <replaceable class="parameter">name</ <title>Notes</title> <para> - While the default index for future - <xref linkend="sql-cluster"/> - operations is retained, <command>REFRESH MATERIALIZED VIEW</command> does not - order the generated rows based on this property. If you want the data - to be ordered upon generation, you must use an <literal>ORDER BY</literal> - clause in the backing query. + If there is an <literal>ORDER BY</literal> clause in the materialized + view's defining query, the original contents of the materialized view + will be ordered that way; but <command>REFRESH MATERIALIZED + VIEW</command> does not guarantee to preserve that ordering. </para> </refsect1> diff --git a/doc/src/sgml/rules.sgml b/doc/src/sgml/rules.sgml index 6b0dc41615..e7fc022c6b 100644 --- a/doc/src/sgml/rules.sgml +++ b/doc/src/sgml/rules.sgml @@ -957,9 +957,6 @@ CREATE MATERIALIZED VIEW sales_summary AS WHERE invoice_date < CURRENT_DATE GROUP BY seller_no, - invoice_date - ORDER BY - seller_no, invoice_date; CREATE UNIQUE INDEX sales_summary_seller |