<html><body><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div>Dear Marco, all,</div><div><br data-mce-bogus="1"></div><div>Let me please add another 2 cents in support of your proposal from the Euro-VO Registry point of view. We also feel <span style="caret-color: #000000; color: #000000; font-family: calibri, helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; background-color: #ffffff; text-decoration: none; display: inline !important; float: none;" data-mce-style="caret-color: #000000; color: #000000; font-family: calibri, helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; background-color: #ffffff; text-decoration: none; display: inline !important; float: none;">ivo_nocasematch offers a well specified, already mandatory definition without the cross-database portability issues that service implementors can find between the I/LIKE implementation in their particular DB and future TAP specification evolution.</span><div style="clear: both;" data-mce-style="clear: both;"><br data-mce-bogus="1"></div></div><div>Regards,</div><div>Juan</div><div><br></div><hr id="zwchr" data-marker="__DIVIDER__"><div data-marker="__HEADERS__"><b>From: </b>"Dave Morris" <dave.morris@metagrid.co.uk><br><b>To: </b>dal@ivoa.net, "IVOA Registry" <registry@ivoa.net><br><b>Sent: </b>Monday, August 12, 2019 1:14:15 PM<br><b>Subject: </b>Re: RegTAP-1.1 & ADQL-2.1 - the ILIKE concerns<br></div><div><br></div><div data-marker="__QUOTED_TEXT__">On 2019-08-12 09:10, Markus Demleitner wrote:<br>> <br>> there'll be two pieces of syntax that are essentially guaranteed to<br>> do the same thing within what ADQL can guarantee in the first place,<br>> <br><br>There is no guarantee that the ADQL ILIKE will always behave the way <br>that RegTAP requires. It may be similar at the moment, because the <br>current definitions deal with ASCII only. That may change in the future.<br><br>> So, I've backed out of requiring ILIKE in RegTAP 1.1 in volute rev<br>> 5570 (diff below). I still couldn't resist the following language:<br>> <br>> Columns intended for presentation are not case-normalised. When<br>> matching against these, queries should use case-insensitive matching,<br>> for which this specification offers the \verb|ivo_nocasematch| user<br>> defined function. ADQL 2.1 is expected to offer an ILIKE operator,<br>> which may be used instead.<br>> <br>> Can everyone live with that?<br>> <br><br>Yep, I'm fine with that as long as you recognise that putting this in <br>the RegTAP document does not place a requirement on DAL/ADQL to maintain <br>compatibility.<br><br>In the future DAL/ADQL may need to change the way that ILIKE handles <br>regular expressions in a way that is not backwards compatible with <br>RegTAP.<br><br>Or alternatively, RegTAP may need to be more specific about how <br>ivo_nocasematch searches handle UTF-8 characters in service descriptions <br>in a way that is hard for some platforms to support. In which case, <br>DAL/ADQL would not be required to make the same changes to ILIKE.<br><br>I'm just looking ahead to three or four years time when one or other of <br>the specifications needs to refine the behaviour in way that is <br>incompatible with the other, they are free to do so and we are not <br>blocked by a guarantee of compatibility.<br><br><br>-- Dave<br><br>--------<br>Dave Morris<br>Research Software Engineer<br>Wide Field Astronomy Unit<br>Institute for Astronomy<br>University of Edinburgh<br>--------<br></div><div><br></div><div data-marker="__SIG_POST__">-- <br></div><div>-- <br>Juan Gonzalez juan.gonzalez@sciops.esa.int<br>ESAC Science Data Centre<br>European Space Agency (ESA) - SERCO<br><br>European Space Astronomy Centre (ESAC)<br>Camino Bajo del Castillo, S/N Tel: +34 91 813 14 82<br>Villanueva de la Canada,, 28691, Madrid, SPAIN Fax: +34 91 813 13 22<br>---------------------------------------------------------------------</div></div><PRE>This message is intended only for the recipient(s) named above. It may contain proprietary information and/or
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