</para>
<para>
Number of data page checksum failures detected in this
- database (or on a shared object), or NULL if data checksums are not
- enabled.
+ database (or on a shared object), or NULL if data checksums are
+ disabled.
</para></entry>
</row>
</para>
<para>
Time at which the last data page checksum failure was detected in
- this database (or on a shared object), or NULL if data checksums are not
- enabled.
+ this database (or on a shared object), or NULL if data checksums are
+ disabled.
</para></entry>
</row>
<para>
The <structfield>checksum</structfield> field is the checksum stored in
the page, which might be incorrect if the page is somehow corrupted. If
- data checksums are not enabled for this instance, then the value stored
+ data checksums are disabled for this instance, then the value stored
is meaningless.
</para>
</listitem>
</listitem>
<listitem>
<para>
- Data pages are not currently checksummed by default, though full page images
- recorded in WAL records will be protected; see <link
- linkend="app-initdb-data-checksums"><application>initdb</application></link>
- for details about enabling data checksums.
+ Data pages are checksummed by default, and full page images
+ recorded in WAL records are always checksum protected.
</para>
</listitem>
<listitem>
</indexterm>
<para>
- By default, data pages are not protected by checksums, but this can
- optionally be enabled for a cluster. When enabled, each data page includes
+ By default, data pages are protected by checksums, but this can
+ optionally be disabled for a cluster. When enabled, each data page includes
a checksum that is updated when the page is written and verified each time
the page is read. Only data pages are protected by checksums; internal data
structures and temporary files are not.
</para>
<para>
- Checksums are normally enabled when the cluster is initialized using <link
+ Checksums can be disabled when the cluster is initialized using <link
linkend="app-initdb-data-checksums"><application>initdb</application></link>.
They can also be enabled or disabled at a later time as an offline
operation. Data checksums are enabled or disabled at the full cluster