$PostgreSQL: pgsql/doc/src/sgml/ref/psql-ref.sgml,v 1.167 2006/08/29 22:25:04 tgl Exp $

<varlistentry>

<term><varname>FETCH_COUNT</varname></term>

<listitem>

<para>

If this variable is set to an integer value &gt; 0,

the results of <command>SELECT</command> queries are fetched

and displayed in groups of that many rows, rather than the

default behavior of collecting the entire result set before

display. Therefore only a

limited amount of memory is used, regardless of the size of

the result set. Settings of 100 to 1000 are commonly used

when enabling this feature.

Keep in mind that when using this feature, a query may

fail after having already displayed some rows.

</para>

<tip>

<para>

Although you can use any output format with this feature,

the default <literal>aligned</> format tends to look bad

because each group of <varname>FETCH_COUNT</varname> rows

will be formatted separately, leading to varying column

widths across the row groups. The other output formats work better.

</para>

</tip>

</listitem>

</varlistentry>