dirty read
<indexterm><primary>dirty read</primary></indexterm>
</term>
- <listitem>
- <para>
+ <listitem>
+ <para>
A transaction reads data written by a concurrent uncommitted transaction.
</para>
</listitem>
nonrepeatable read
<indexterm><primary>nonrepeatable read</primary></indexterm>
</term>
- <listitem>
- <para>
+ <listitem>
+ <para>
A transaction re-reads data it has previously read and finds that data
has been modified by another transaction (that committed since the
initial read).
phantom read
<indexterm><primary>phantom read</primary></indexterm>
</term>
- <listitem>
- <para>
+ <listitem>
+ <para>
A transaction re-executes a query returning a set of rows that satisfy a
search condition and finds that the set of rows satisfying the condition
has changed due to another recently-committed transaction.
serialization anomaly
<indexterm><primary>serialization anomaly</primary></indexterm>
</term>
- <listitem>
- <para>
+ <listitem>
+ <para>
The result of successfully committing a group of transactions
is inconsistent with all possible orderings of running those
transactions one at a time.
changes in the table. A repeatable read transaction's snapshot is actually
frozen at the start of its first query or data-modification command
(<literal>SELECT</literal>, <literal>INSERT</literal>,
- <literal>UPDATE</literal>, or <literal>DELETE</literal>), so
- it is possible to obtain locks explicitly before the snapshot is
- frozen.
+ <literal>UPDATE</literal>, <literal>DELETE</literal>, or
+ <literal>MERGE</literal>), so it is possible to obtain locks explicitly
+ before the snapshot is frozen.
</para>
</sect2>
</sect1>