I have to agree with Hernan.
The simplest saving I can see is an extra column to save on the "run time" calculation. This does not have to be dangerous (ie potentially different to the date column you have already)Just setup a trigger for whenever the existing date column gets updated(/inserted) to update the extra column.
Another alternative is to use a materialised view. On Postgres this is a manual process involving setting up a view and rules, and ig you want it always up to date, triggers again on the source table to update the materialised view whenever the data changes.
This latter idea would be the fastest - faster than your original view by quite a margin, in fact. You may then be able to get rid of some (all?) indexes you have already on the existing table - because they would no longer be needed.
One thing I think would be handy that I have on my list of "when I get time" is to write some reasonably automatic code to do materialised views without the manual coding (ala Oracle). People may use these things more if they were a bit more simple to do.
Link to Need Help Reducing View Calculations page: http://www.justatheory.com/computers/databases/postgresql/reducing_view_calculations.html
]]>The argument that I have been unable to win in putting together a warehouse on PostgreSQL comes down to tool maturity - ie the risk involved in something "not proven" so it is almost certainly going to be built using Oracle Warehouse Builder and a BI tool tbd.
I have a long history with databases, and experience with PostgreSQL that dates to the beginning of version 7, however I've never been involved in formal datawarehousing or ETL - so I can't speak with the authority I would prefer ;-)
From my research (mostly involving asking Liam at Fujitsu) Bizgres which seems to be still at the "not finished" stage, and Jasper. I have experience in Jasper products from some time back - they looked very good then - so I can't wait to try out JasperETL.
In any case I am likely to do a parallel run of the work with OWB using Jasper/Postgres to see how they go in my own time. I would welcome any comments on all this - particularly if they can be backed up with real-world datawarehousing projects.
For those wondering about this blog, family illness has kept me from this for some time, unfortunately... something that is now coming to an end in a good way.
Cheers,
Mathew Frank (http://frakkle.com)
]]><?php]]>
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function mime_content_type($filename) {
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'aifc' =>'audio/x-aiff',
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'asc' =>'text/plain',
'atom' =>'application/atom+xml',
'avi' =>'video/x-msvideo',
'bcpio' =>'application/x-bcpio',
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'cdf' =>'application/x-netcdf',
'cgm' =>'image/cgm',
'cpio' =>'application/x-cpio',
'cpt' =>'application/mac-compactpro',
'crl' =>'application/x-pkcs7-crl',
'crt' =>'application/x-x509-ca-cert',
'csh' =>'application/x-csh',
'css' =>'text/css',
'dcr' =>'application/x-director',
'dir' =>'application/x-director',
'djv' =>'image/vnd.djvu',
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'doc' =>'application/msword',
'dtd' =>'application/xml-dtd',
'dvi' =>'application/x-dvi',
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'eps' =>'application/postscript',
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'ez' =>'application/andrew-inset',
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'gram' =>'application/srgs',
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'gtar' =>'application/x-gtar',
'hdf' =>'application/x-hdf',
'hqx' =>'application/mac-binhex40',
'html' =>'text/html',
'html' =>'text/html',
'ice' =>'x-conference/x-cooltalk',
'ico' =>'image/x-icon',
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'ifb' =>'text/calendar',
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'igs' =>'model/iges',
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'mov' =>'video/quicktime',
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'pgn' =>'application/x-chess-pgn',
'php' =>'application/x-httpd-php',
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'php3' =>'application/x-httpd-php',
'phtml' =>'application/x-httpd-php',
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'png' =>'image/png',
'pnm' =>'image/x-portable-anymap',
'ppm' =>'image/x-portable-pixmap',
'ppt' =>'application/vnd.ms-powerpoint',
'ps' =>'application/postscript',
'qt' =>'video/quicktime',
'ra' =>'audio/x-pn-realaudio',
'ram' =>'audio/x-pn-realaudio',
'ras' =>'image/x-cmu-raster',
'rdf' =>'application/rdf+xml',
'rgb' =>'image/x-rgb',
'rm' =>'application/vnd.rn-realmedia',
'roff' =>'application/x-troff',
'rtf' =>'text/rtf',
'rtx' =>'text/richtext',
'sgm' =>'text/sgml',
'sgml' =>'text/sgml',
'sh' =>'application/x-sh',
'shar' =>'application/x-shar',
'shtml' =>'text/html',
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'sit' =>'application/x-stuffit',
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'skm' =>'application/x-koan',
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'skt' =>'application/x-koan',
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'src' =>'application/x-wais-source',
'sv4cpio' =>'application/x-sv4cpio',
'sv4crc' =>'application/x-sv4crc',
'svg' =>'image/svg+xml',
'swf' =>'application/x-shockwave-flash',
't' =>'application/x-troff',
'tar' =>'application/x-tar',
'tcl' =>'application/x-tcl',
'tex' =>'application/x-tex',
'texi' =>'application/x-texinfo',
'texinfo' =>'application/x-texinfo',
'tgz' =>'application/x-tar',
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'tiff' =>'image/tiff',
'tr' =>'application/x-troff',
'tsv' =>'text/tab-separated-values',
'txt' =>'text/plain',
'ustar' =>'application/x-ustar',
'vcd' =>'application/x-cdlink',
'vrml' =>'model/vrml',
'vxml' =>'application/voicexml+xml',
'wav' =>'audio/x-wav',
'wbmp' =>'image/vnd.wap.wbmp',
'wbxml' =>'application/vnd.wap.wbxml',
'wml' =>'text/vnd.wap.wml',
'wmlc' =>'application/vnd.wap.wmlc',
'wmlc' =>'application/vnd.wap.wmlc',
'wmls' =>'text/vnd.wap.wmlscript',
'wmlsc' =>'application/vnd.wap.wmlscriptc',
'wmlsc' =>'application/vnd.wap.wmlscriptc',
'wrl' =>'model/vrml',
'xbm' =>'image/x-xbitmap',
'xht' =>'application/xhtml+xml',
'xhtml' =>'application/xhtml+xml',
'xls' =>'application/vnd.ms-excel',
'xml xsl' =>'application/xml',
'xpm' =>'image/x-xpixmap',
'xslt' =>'application/xslt+xml',
'xul' =>'application/vnd.mozilla.xul+xml',
'xwd' =>'image/x-xwindowdump',
'xyz' =>'chemical/x-xyz',
'zip' =>'application/zip'
);
if (isset( $mimet[$idx] )) {
return $mimet[$idx];
} else {
return 'application/octet-stream';
}
}
}
?>