RE: No primary keys
This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ------_=_NextPart_001_01C07988.57E6E7FC Content-Type: text/plain; charset="iso-8859-1" Not normally. It will allow duplicate data, and not perform RI checks - there is no law against duplicate data. OTOH, you may issue a query which results in an 'autoindex' - the optimizer decides it would be cheaper to build an index to satisfy your query and does so. cheers j. -----Original Message----- From: Wayne Hansford [mailto:hansford@salemleasing.com] Sent: Monday, January 08, 2001 8:26 AM To: Informix mail Subject: No primary keys What does Informix do if there are no primary key or foriegn key attributes defined in the database schema ? Will Informix try to build a primary key Index based on as many fields as it thinks it needs for record uniqueness ? Is this process expensive in terms of compute time ? Thanks, Thomas Hansford hansford@salemleasing.com <mailto:hansford@salemleasing.com> Sr. Software Engineer Manpower Professional Services ------_=_NextPart_001_01C07988.57E6E7FC Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META HTTP-EQUIV=3D"Content-Type" CONTENT=3D"text/html; = charset=3Diso-8859-1"> <META content=3D"MSHTML 5.50.4134.600" name=3DGENERATOR></HEAD> <BODY style=3D"FONT-FAMILY: Arial" text=3D#000000 bgColor=3D#ffffff> <DIV><FONT size=3D2></FONT> </DIV> <DIV><SPAN class=3D379203115-08012001><FONT size=3D2>Not = normally. It will=20 allow duplicate data, and not perform RI checks - there is no law = against=20 duplicate data. </FONT></SPAN></DIV> <DIV><SPAN class=3D379203115-08012001><FONT = size=3D2></FONT></SPAN> </DIV> <DIV><SPAN class=3D379203115-08012001><FONT size=3D2>OTOH, you may = issue a query=20 which results in an 'autoindex' - the optimizer decides it would be = cheaper to=20 build an index to satisfy your query and does so.</FONT></SPAN></DIV> <DIV><SPAN class=3D379203115-08012001><FONT = size=3D2></FONT></SPAN> </DIV> <DIV><SPAN class=3D379203115-08012001><FONT = size=3D2>cheers</FONT></SPAN></DIV> <DIV><SPAN class=3D379203115-08012001><FONT = size=3D2>j.</FONT></SPAN></DIV> <BLOCKQUOTE dir=3Dltr=20 style=3D"PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px = solid; MARGIN-RIGHT: 0px"> <DIV class=3DOutlookMessageHeader dir=3Dltr align=3Dleft><FONT = face=3DTahoma=20 size=3D2>-----Original Message-----<BR><B>From:</B> Wayne Hansford=20 [mailto:hansford@salemleasing.com]<BR><B>Sent:</B> Monday, January = 08, 2001=20 8:26 AM<BR><B>To:</B> Informix mail<BR><B>Subject:</B> No primary=20 keys<BR><BR></FONT></DIV> <DIV><FONT size=3D2> What does Informix do if there are no = primary key or=20 foriegn key attributes defined in the database schema ? Will Informix = try to=20 build a primary key Index based on as many fields as it thinks it = needs for=20 record uniqueness ? Is this process expensive in terms of compute = time ?=20 </FONT></DIV> <DIV> </DIV> <DIV> </DIV> <DIV> </DIV> <DIV> </DIV> <DIV> </DIV> = <DIV> &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; = Thanks,</DIV> <DIV> </DIV> = <DIV> &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; = Thomas Hansford</DIV> = <DIV> &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp;=20 <A = href=3D"mailto:hansford@salemleasing.com">hansford@salemleasing.com</A><= /DIV> = <DIV> &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; &= nbsp; = </DIV><BR> <META content=3D"MSHTML 5.00.2614.3500" name=3DGENERATOR> <DIV>Sr. Software Engineer</DIV> <DIV>Manpower Professional Services</DIV></BLOCKQUOTE></BODY></HTML> ------_=_NextPart_001_01C07988.57E6E7FC--