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    <p>Ah, I think I know what your issue is. According to the <a href="http://dev.mysql.com/doc/refman/5.1/en/index-hints.html" rel="nofollow">MySQL documentation</a>:</p> <blockquote> <p>By specifying USE INDEX (index_list), you can tell MySQL to use only one of the named indexes to find rows in the table. The alternative syntax IGNORE INDEX (index_list) can be used to tell MySQL to not use some particular index or indexes. These hints are useful if EXPLAIN shows that MySQL is using the wrong index from the list of possible indexes.</p> <p>You can also use FORCE INDEX, which acts like USE INDEX (index_list) but with the addition that a table scan is assumed to be very expensive. In other words, a table scan is used only if there is no way to use one of the given indexes to find rows in the table.</p> </blockquote> <p>In other words, by using FORCE INDEX, you're telling MySQL to <em>only</em> use the <code>customer_history_n2</code> index and skip over all of the other available indexes. You need to remove the FORCE INDEX clause from your query, or else specify it as this instead so that it will use the indexes for the other columns that are available:</p> <pre><code>SELECT customer_history.customer_id, customer_history.row_mod, customer_history.row_create, customer_history.event_id, customer_history.event_type, customer_history.new_value, customer_history.old_value FROM customer_history FORCE INDEX (customer_history_n2, customer_history_n1, customer_id1) WHERE customer_id &gt;= 1 AND customer_id &lt; 5000000 AND (customer_history.row_mod &gt;= '2012-10-01') OR ( customer_history.row_create &gt;= '2012-10-01' AND customer_history.row_create &lt; '2012-10-13' ); </code></pre>
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    1. COBy the way, with 30 million records, you might want to SERIOUSLY consider some horizontal partitioning of your database. If you frequently query your database for all dates within, for example, a month, you can partition it by range. I suggest reading this article for more information, as it can have a seriously positive impact on your database's performance. http://dev.mysql.com/tech-resources/articles/partitioning.html
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Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

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