(just like a <glossterm linkend="glossary-view">view</glossterm>),

but stores data in the same way that a

<glossterm linkend="glossary-table">table</glossterm> does. It cannot be

modified via <command>INSERT</command>, <command>UPDATE</command>, or

<command>DELETE</command> operations.

modified via <command>INSERT</command>, <command>UPDATE</command>,

<command>DELETE</command>, or <command>MERGE</command> operations.

</para>

<para>

For more information, see

</glossdef>

</glossentry>

<glossentry id="glossary-merge">

<glossterm>Merge</glossterm>

<glossdef>

<para>

An <acronym>SQL</acronym> command used to conditionally add, modify,

or remove <glossterm linkend="glossary-tuple">rows</glossterm>

in a given <glossterm linkend="glossary-table">table</glossterm>,

using data from a source

<glossterm linkend="glossary-relation">relation</glossterm>.

</para>

<para>

For more information, see

<xref linkend="sql-merge"/>.

</para>

</glossdef>

</glossentry>

<glossentry id="glossary-mvcc">

<glossterm>Multi-version concurrency control (MVCC)</glossterm>

<glossdef>

that are referred to in the <literal>SET</literal> clause.

If you specify an insert action, you must have the <literal>INSERT</literal>

privilege on the <replaceable class="parameter">target_table_name</replaceable>.

If you specifyan delete action, you must have the <literal>DELETE</literal>

If you specifya delete action, you must have the <literal>DELETE</literal>

privilege on the <replaceable class="parameter">target_table_name</replaceable>.

Privileges are tested once at statement start and are checked

whether or not particular <literal>WHEN</literal> clauses are executed.

You will require the <literal>SELECT</literal> privilege onthe

<replaceable class="parameter">data_source</replaceable> and any column(s)

of the<replaceable class="parameter">target_table_name</replaceable>

referred toina <literal>condition</literal>.

You will require the <literal>SELECT</literal> privilege onany column(s)

of the<replaceable class="parameter">data_source</replaceable> and

<replaceable class="parameter">target_table_name</replaceable> referred to

inany <literal>condition</literal> or <literal>expression</literal>.

</para>

<para>