t"><a accesskey="p" href="indexes-expressional.html" title="11.7. Indexes on Expressions">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="indexes.html" title="Chapter 11. Indexes">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="indexes-index-only-scans.html" title="11.9. Index-Only Scans and Covering Indexes">Next</a></td></tr><tr><td width="40%" align="left" valign="top">11.7. Indexes on Expressions </td><td width="20%" align="center"><a accesskey="h" href="inde