Are rowids always in increasing order?

Posted in 2004

Summary

Asked whether IDS 9.3 assigns rowids in strictly increasing order. Answer from the thread: no. A rowid is just a physical address (logical page offset within the tablespace plus slot number within the page), not an incrementing counter, so a new row dropped into a partly empty earlier page gets a lower rowid than rows on later pages. Rowids can also change (in-place alter, unload/reload), and fragmented tables have none unless created WITH ROWIDS, which adds an index and overhead. Consensus: don't rely on rowid ordering or stability.

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Topics: General Discussion

Jean Sagi — Thu, 22 Apr 2004 23:13:08 — source: IIUG Forums & Mailing Lists

Hi, I wonder if anyone one knows if IDS (9.3) asigns rowids in increasing order? I mean Always. In the documentation it i stated that: "The database server assigns to each row in the rowid column a unique number that remains stable for the life of the row." But I haven't found any indication that the numbers asigned to the rowdis are always choosed in increasing order. If anyone know, let me know . I'll appreciate it a lot. Chucho! Jean Sagi jeansagi@myrealbox.com jeansagi@netscape.net

↪ replying to Jean Sagi

Rajib Sarkar — Fri, 23 Apr 2004 00:34:07 — source: IIUG Forums & Mailing Lists

--0__=88BBE4ECDF91A3BE8f9e8a93df938690918c88BBE4ECDF91A3BE Content-type: multipart/alternative; Boundary="1__=88BBE4ECDF91A3BE8f9e8a93df938690918c88BBE4ECDF91A3BE" --1__=88BBE4ECDF91A3BE8f9e8a93df938690918c88BBE4ECDF91A3BE Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: quoted-printable Rowid is of the format 0xLLLLLLSS where L =3D logical page offset withi= n tablespace and S =3D slot# within page. When the engine starts allocating pages for the table, usually its contiguous and with increasing offset into the table ..but there maybe = a situation in a table where say there are 5000 pages already allocated f= or the table and there are some holes in the pages i.e. all of the pages a= re not full with rows and potentially more rows can be fitted into the pag= es ..then it maybe that a new row is put in page offset 2000 ..then the RO= WID will be less than the row residing on page 5000. U hv to visualize ROWID as a physical representation of a row ..when a = user asks the engine to get a particular row ..it can get the ROWID (from th= e index) and immediately go into the page without doing any further calculation ...so yes, its right that the ROWID is unique for the lifet= ime of the row IN THE PAGE. In an IN PLACE ALTER situation, when u update t= he row it may be relocated to another page and a new rowid is representing= the row now. ROWID is no internal integer which the engine increments every= time a row is inserted ..ROWID is the means for the engine to reach the= row in the quickest possible way ... HTH Thanx much, Rajib Sarkar Advisory Software Engineer (RAS) IBM Data Management Group If we all did the things we are capable of doing, we would literally astound ourselves. -- T. Edison = "Jean Sagi" = <jeansagi@myrealb = ox.com> = To Sent by: ids@iiug.org = forum.subscriber@ = cc iiug.org = Subj= ect Are rowids always in increasing = 04/22/2004 04:13 order? [2867] = PM = = = = = = Hi, I wonder if anyone one knows if IDS (9.3) asigns rowids in increasing order? I mean Always. In the documentation it i stated that: "The database server assigns to each row in the rowid column a unique number that remains stable for the life of the row." But I haven't found any indication that the numbers asigned to the rowd= is are always choosed in increasing order. If anyone know, let me know . I'll appreciate it a lot. Chucho! Jean Sagi jeansagi@myrealbox.com jeansagi@netscape.net = --1__=88BBE4ECDF91A3BE8f9e8a93df938690918c88BBE4ECDF91A3BE Content-type: text/html; charset=US-ASCII Content-Disposition: inline Content-transfer-encoding: quoted-printable <html><body> Rowid is of the format 0xLLLLLLSS where L =3D logical page offset wi= thin tablespace and S =3D slot# within page. When the engine starts allocating pages for the table, usually its cont= iguous and with increasing offset into the table ..but there maybe a si= tuation in a table where say there are 5000 pages already allocated for= the table and there are some holes in the pages i.e. all of the pages = are not full with rows and potentially more rows can be fitted into the= pages ..then it maybe that a new row is put in page offset 2000 ..then= the ROWID will be less than the row residing on page 5000. U hv to visualize ROWID as a physical representation of a row ..when a = user asks the engine to get a particular row ..it can get the ROWID (fr= om the index) and immediately go into the page without doing any furthe= r calculation ...so yes, its right that the ROWID is unique for the lif= etime of the row IN THE PAGE. In an IN PLACE ALTER situation, wh= en u update the row it may be relocated to another page and a new rowid= is representing the row now. ROWID is no internal integer which the en= gine increments every time a row is inserted ..ROWID is the means for t= he engine to reach the row in the quickest possible way ... HTH Thanx much, Rajib Sarkar Advisory Software Engineer (RAS) IBM Data Management Group If we all did the things we are capable of doing, we would literally as= tound ourselves. -- T. Edison <img src=3D"cid:10__=3D88BBE4ECDF91A3BE8f9e8a93df938@us.ibm.com" width=3D= "16" height=3D"16" alt=3D"Inactive hide details for "Jean Sagi&quo= t; <jeansagi@myrealbox.com>">"Jean Sagi" <jeansagi@m= yrealbox.com> <table width=3D"100%" border=3D"0" cellspacing=3D"0" cellpadding=3D"0">= <tr valign=3D"top"><td style=3D"background-image:url(cid:20__=3D88BBE4E= CDF91A3BE8f9e8a93df938@us.ibm.com); background-repeat: no-repeat; " wid= th=3D"40%"> <ul> <ul> <ul> <ul>"Jean Sagi" <jeansagi@myrealbox.co= m> Sent by: forum.subscriber@iiug.org 04/22/2004 04:13 PM</ul> </ul> </ul> </ul> </td><td width=3D"60%"> <table width=3D"100%" border=3D"0" cellspacing=3D"0" cellpadding=3D"0">= <tr valign=3D"top"><td width=3D"1%" valign=3D"middle"><img src=3D"cid:3= 0__=3D88BBE4ECDF91A3BE8f9e8a93df938@us.ibm.com" border=3D"0" height=3D"= 1" width=3D"58" alt=3D""> <div align=3D"right">To</div></td><td width=3D"= 100%"><img src=3D"cid:30__=3D88BBE4ECDF91A3BE8f9e8a93df938@us.ibm.com" = border=3D"0" height=3D"1" width=3D"1" alt=3D""> ids@iiug.org</td></tr> <tr valign=3D"top"><td width=3D"1%" valign=3D"middle"><img src=3D"cid:3= 0__=3D88BBE4ECDF91A3BE8f9e8a93df938@us.ibm.com" border=3D"0" height=3D"= 1" width=3D"58" alt=3D""> <div align=3D"right">cc</div></td><td width=3D"= 100%"><img src=3D"cid:30__=3D88BBE4ECDF91A3BE8f9e8a93df938@us.ibm.com" = border=3D"0" height=3D"1" width=3D"1" alt=3D""> </td></tr> <tr valign=3D"top"><td width=3D"1%" valign=3D"middle"><img src=3D"cid:3= 0__=3D88BBE4ECDF91A3BE8f9e8a93df938@us.ibm.com" border=3D"0" height=3D"= 1" width=3D"58" alt=3D""> <div align=3D"right">Subject</div></td><td widt= h=3D"100%"><img src=3D"cid:30__=3D88BBE4ECDF91A3BE8f9e8a93df938@us.ibm.= com" border=3D"0" height=3D"1" width=3D"1" alt=3D@@D

↪ replying to Jean Sagi

Madison Pruet — Fri, 23 Apr 2004 01:45:15 — source: IIUG Forums & Mailing Lists

--0__=09BBE4ECDF9AB60D8f9e8a93df938690918c09BBE4ECDF9AB60D Content-type: multipart/alternative; Boundary="1__=09BBE4ECDF9AB60D8f9e8a93df938690918c09BBE4ECDF9AB60D" --1__=09BBE4ECDF9AB60D8f9e8a93df938690918c09BBE4ECDF9AB60D Content-type: text/plain; charset=US-ASCII no. Where in the documentation does it state this? "Jean Sagi" <jeansagi@myrealb To: ids@iiug.org ox.com> cc: Sent by: Subject: Are rowids always in increasing order? [2867] forum.subscriber@ iiug.org 04/22/2004 06:13 PM Hi, I wonder if anyone one knows if IDS (9.3) asigns rowids in increasing order? I mean Always. In the documentation it i stated that: "The database server assigns to each row in the rowid column a unique number that remains stable for the life of the row." But I haven't found any indication that the numbers asigned to the rowdis are always choosed in increasing order. If anyone know, let me know . I'll appreciate it a lot. Chucho! Jean Sagi jeansagi@myrealbox.com jeansagi@netscape.net --1__=09BBE4ECDF9AB60D8f9e8a93df938690918c09BBE4ECDF9AB60D Content-type: text/html; charset=US-ASCII Content-Disposition: inline <html><body> no. Where in the documentation does it state this? <img src="cid:10__=09BBE4ECDF9AB60D8f9e8a93df938@us.ibm.com" width="16" height="16" alt="Inactive hide details for "Jean Sagi" <jeansagi@myrealbox.com>">"Jean Sagi" <jeansagi@myrealbox.com> <table V5DOTBL=true width="100%" border="0" cellspacing="0" cellpadding="0"> <tr valign="top"><td width="1%"><img src="cid:20__=09BBE4ECDF9AB60D8f9e8a93df938@us.ibm.com" border="0" height="1" width="72" alt=""> </td><td style="background-image:url(cid:30__=09BBE4ECDF9AB60D8f9e8a93df938@us.ibm.com); background-repeat: no-repeat; " width="1%"><img src="cid:20__=09BBE4ECDF9AB60D8f9e8a93df938@us.ibm.com" border="0" height="1" width="225" alt=""> <ul> <ul> <ul> <ul>"Jean Sagi" <jeansagi@myrealbox.com> Sent by: forum.subscriber@iiug.org 04/22/2004 06:13 PM</ul> </ul> </ul> </ul> </td><td width="100%"><img src="cid:20__=09BBE4ECDF9AB60D8f9e8a93df938@us.ibm.com" border="0" height="1" width="1" alt=""> To: ids@iiug.org cc: Subject: Are rowids always in increasing order? [2867]</td></tr> </table> <tt>Hi, I wonder if anyone one knows if IDS (9.3) asigns rowids in increasing order? I mean Always. In the documentation it i stated that: "The database server assigns to each row in the rowid column a unique number that remains stable for the life of the row." But I haven't found any indication that the numbers asigned to the rowdis are always choosed in increasing order. If anyone know, let me know . I'll appreciate it a lot. Chucho! Jean Sagi jeansagi@myrealbox.com jeansagi@netscape.net </tt> </body></html> --1__=09BBE4ECDF9AB60D8f9e8a93df938690918c09BBE4ECDF9AB60D-- --0__=09BBE4ECDF9AB60D8f9e8a93df938690918c09BBE4ECDF9AB60D Content-type: image/gif; name="graycol.gif" Content-Disposition: inline; filename="graycol.gif" Content-ID: <10__=09BBE4ECDF9AB60D8f9e8a93df938@us.ibm.com> Content-transfer-encoding: base64 R0lGODlhEAAQAKECAMzMzAAAAP///wAAACH5BAEAAAIALAAAAAAQABAAAAIXlI+py+0PopwxUbpu ZRfKZ2zgSJbmSRYAIf4fT3B0aW1pemVkIGJ5IFVsZWFkIFNtYXJ0U2F2ZXIhAAA7 --0__=09BBE4ECDF9AB60D8f9e8a93df938690918c09BBE4ECDF9AB60D Content-type: image/gif; name="ecblank.gif" Content-Disposition: inline; filename="ecblank.gif" Content-ID: <20__=09BBE4ECDF9AB60D8f9e8a93df938@us.ibm.com> Content-transfer-encoding: base64 R0lGODlhEAABAIAAAAAAAP///yH5BAEAAAEALAAAAAAQAAEAAAIEjI8ZBQA7 --0__=09BBE4ECDF9AB60D8f9e8a93df938690918c09BBE4ECDF9AB60D Content-type: image/gif; name="pic11349.gif" Content-Disposition: inline; filename="pic11349.gif" Content-ID: <30__=09BBE4ECDF9AB60D8f9e8a93df938@us.ibm.com> Content-transfer-encoding: base64 R0lGODlhWABDALP/AAAAAK04Qf79/o+Gm7WuwlNObwoJFCsoSMDAwGFsmIuezf///wAAAAAAAAAA AAAAACH5BAEAAAgALAAAAABYAEMAQAT/EMlJq704682770RiFMRinqggEUNSHIchG0BCfHhOjAuh EDeUqTASLCbBhQrhG7xis2j0lssNDopE4jfIJhDaggI8YB1sZeZgLVA9YVCpnGagVjV171aRVrYR RghXcAGFhoUETwYxcXNyADJ3GlcSKGAwLwllVC1vjIUHBWsFilKQdI8GA5IcpApeJQt8L09lmgkH LZikoU5wjqcyAMMFrJIDPAKvCFletKSev1HBw8KrxtjZ2tvc3d5VyKtCKW3jfz4uMKmq3xu4N0nK BVoJQmx2LGVOmrqNjjJf2hHAQo/eDwJGTKhQMcgQEEAnEjFS98+RnW3smGkZU6ncCWav/4wYOnAI TihRL/4FEwbp28BXMMcoscQCVxlepL4IGDSCyJyVQOu0o7CjmLN50OZlqWmyFy5/6yBBuji0AxFR M00oQAqNIstqI6qKHUsWRAEAvagsmfUEAImyxgbmUpJk3IklNUtJOUAVLoUr1+wqDGTE4zk+T6FG uQb3SizBCwatiiUgCBN8vrz+zFjVyQ8FWkOlg4NQiZMB5QS8QO3mpOaKnL0Z2EKvNMSILEThKhCg zMKPVxYJh23qm9KNW7pArPynMqZDiErsTMqI+LRi3QAgkFUbXpuFKhSYZALd0O5RKa2z9EYKBbpb qxIKsjUPRgD7I2XYV6wyrOw92ykExP8NW4URhknC5dKGE4v4NENQj2jXjmfNgOZDaXb5glRmXQ33 YEWQYNcZFnrYcIQLNzyTFDQNkXIff0ExVlY4srziQk43inZgL4rwxxINMvpFFAz1KOODHiu+4aEw NEjFl5B3JIKWKF3k6I9bfUGp5ZZcdunll5IA4cuHvQQJ5gcsoCWOOUwgltIwAKRxJgbIkJAQZEq0 2YliZnpZZ4BH3CnYOXldOUOfQoYDqF1LFHbXCrO8xmRsfoXDXJ6ChjCAH3QlhJcT6VWE6FCkfCco CgrMFsROrIEX3o2whVjWDjoJccN3LdggSGXLCdLEgHr1lyU3O3QxhgohNKXJCWv8JQr/PDdaqd6w 2rj1inLiGeiCJoDspAoQlYE6QWLSECehcWIYxIQES6zhbn1iImTHEQyqJ4eIxJJoUBc+3CbBuwZE V5cJPPkIjFDdeEabQbd6WgICTxiiz0f5dBKquXF6k4senwEhYGnKEFJeGrxUZy8dB8gmAXI/sPvH ESfCwVt5hTgYiqQqtdRNHQIU1PJ33ZqmzgE90OwLaoJcnMop1WiMmgkPHQRIrwgFuNV90A3doNKT mrKIN07AnGcI9BQjhCBN4RfA1qIZnMqorJCogKfGQnxSCDilTVIA0yl5ciTovgLuBDKFUDE9aQcw 9SA+rjSNf9/M1gxrj6VwDTS0IUSElMzBfsj0NFXR2kwsV1A5IF1grLgLL/r1R40BZEnuBWgmQEyb jqRwSAt6bqMCOFkvKFN2GPPkUzIm/SCF8z8pVzpbjVnMsy0vOr1hw3SaSRUhpY09v0z0J1FnwzPl fmh+xl4WtR0zGu24I4KbMQm3lnVu2oNWxI9W/lcyzA+mCKF4DBikxb/+UWtOGRiFP8qEwAayIgIA Ow== --0__=09BBE4ECDF9AB60D8f9e8a93df938690918c09BBE4ECDF9AB60D--

↪ replying to Rajib Sarkar

NormaJean.Sebastian@tellabs.com — Fri, 23 Apr 2004 02:44:15 — source: IIUG Forums & Mailing Lists

While the technical explanation of rowid is always appreciated, hasn't it been a pretty well accepted "rule" for some time (possibly around IDS 5.0 days or earlier) that applications/scripts/customers should not be using rowid....rowid is "property" of informix/ibm.... and subject to change if needed... wasn't it the rowid that underwent concept change when fragmentation was introduced? i remember many a training class that emphasized customers should not rely on rowid, it is not guaranteed to stay consistent per version.... Norma Jean -----Original Message----- From: rsarkar@us.ibm.com [mailto:rsarkar@us.ibm.com] Sent: Thursday, April 22, 2004 7:34 PM To: ids@iiug.org; forum.subscriber@iiug.org Subject: Re: Are rowids always in increasing order? [2869] Rowid is of the format 0xLLLLLLSS where L =3D logical page offset withi= n tablespace and S =3D slot# within page. When the engine starts allocating pages for the table, usually its contiguous and with increasing offset into the table ..but there maybe = a situation in a table where say there are 5000 pages already allocated f= or the table and there are some holes in the pages i.e. all of the pages a= re not full with rows and potentially more rows can be fitted into the pag= es .then it maybe that a new row is put in page offset 2000 ..then the RO= WID will be less than the row residing on page 5000. U hv to visualize ROWID as a physical representation of a row ..when a = user asks the engine to get a particular row ..it can get the ROWID (from th= e index) and immediately go into the page without doing any further calculation ...so yes, its right that the ROWID is unique for the lifet= ime of the row IN THE PAGE. In an IN PLACE ALTER situation, when u update t= he row it may be relocated to another page and a new rowid is representing= the row now. ROWID is no internal integer which the engine increments every= time a row is inserted ..ROWID is the means for the engine to reach the= row in the quickest possible way ... HTH Thanx much, Rajib Sarkar Advisory Software Engineer (RAS) IBM Data Management Group If we all did the things we are capable of doing, we would literally astound ourselves. -- T. Edison = "Jean Sagi" = <jeansagi@myrealb = ox.com> = To Sent by: ids@iiug.org = forum.subscriber@ = cc iiug.org = Subj= ect Are rowids always in increasing = 04/22/2004 04:13 order? [2867] = PM = = = = = = Hi, I wonder if anyone one knows if IDS (9.3) asigns rowids in increasing order? I mean Always. In the documentation it i stated that: "The database server assigns to each row in the rowid column a unique number that remains stable for the life of the row." But I haven't found any indication that the numbers asigned to the rowd= is are always choosed in increasing order. If anyone know, let me know . I'll appreciate it a lot. Chucho! Jean Sagi jeansagi@myrealbox.com jeansagi@netscape.net ----------------------------------------- ============================================================ The information contained in this message may be privileged and confidential and protected from disclosure. If the reader of this message is not the intended recipient, or an employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any reproduction, dissemination or distribution of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by replying to the message and deleting it from your computer. Thank you. Tellabs ============================================================

↪ replying to Rajib Sarkar

Rajib Sarkar — Fri, 23 Apr 2004 15:13:42 — source: IIUG Forums & Mailing Lists

--0__=88BBE4ECDFC14A818f9e8a93df938690918c88BBE4ECDFC14A81 Content-type: multipart/related; Boundary="1__=88BBE4ECDFC14A818f9e8a93df938690918c88BBE4ECDFC14A81" --1__=88BBE4ECDFC14A818f9e8a93df938690918c88BBE4ECDFC14A81 Content-type: multipart/alternative; Boundary="2__=88BBE4ECDFC14A818f9e8a93df938690918c88BBE4ECDFC14A81" --2__=88BBE4ECDFC14A818f9e8a93df938690918c88BBE4ECDFC14A81 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: quoted-printable Yes for fragmentation, rowids are not generated by default as a fragmen= t internally is represented as a "seperate tablespace" and since ROWID is= a representation of the logical page offset within a page for a fragmente= d table rows in different fragments can potentially have the same ROWID. That's why when you create the table "WITH ROWIDS" option a special row= id index is created which has got the "fragment partnum, page offset and slot#" to identify the row uniquely in a fragmented table. That's the reason relying on ROWID is not recommended as a) it can change -- in IN PLACE ALTER situations, UNLOAD/LOAD etc. b) fragmented tables don't have ROWIDs by default, but if you create th= e rowids, it adds to an overhead of going through the ROWID index to get = to the row and also it occupies extra space as its no more "virtual". HTH Thanx much, Rajib Sarkar Advisory Software Engineer (RAS) IBM Data Management Group If we all did the things we are capable of doing, we would literally astound ourselves. -- T. Edison = NormaJean.Sebasti = an@tellabs.com = = To 04/22/2004 07:39 forum.subscriber@iiug.org, = PM ids@iiug.org, Rajib = Sarkar/Phoenix/IBM@IBMUS = = cc = Subj= ect RE: Are rowids always in increas= ing order? [2869] = = = = = = = While the technical explanation of rowid is always appreciated, hasn't it been a pretty well accepted "rule" for some time (possibly around ID= S 5.0 days or earlier) that applications/scripts/customers should not be using rowid....rowid is "property" of informix/ibm.... and subject to change if needed... wasn't it the rowid that underwent concept change when fragmentation wa= s introduced? i remember many a training class that emphasized customers should not rely on rowid, it is not guaranteed to stay consistent per version.... Norma Jean -----Original Message----- From: rsarkar@us.ibm.com [mailto:rsarkar@us.ibm.com] Sent: Thursday, April 22, 2004 7:34 PM To: ids@iiug.org; forum.subscriber@iiug.org Subject: Re: Are rowids always in increasing order? [2869] Rowid is of the format 0xLLLLLLSS where L =3D3D logical page offset wit= hi=3D n tablespace and S =3D3D slot# within page. When the engine starts allocating pages for the table, usually its contiguous and with increasing offset into the table ..but there maybe = =3D a situation in a table where say there are 5000 pages already allocated f= =3D or the table and there are some holes in the pages i.e. all of the pages a= =3D re not full with rows and potentially more rows can be fitted into the pag= =3D es .then it maybe that a new row is put in page offset 2000 ..then the RO=3D= WID will be less than the row residing on page 5000. U hv to visualize ROWID as a physical representation of a row ..when a = =3D user asks the engine to get a particular row ..it can get the ROWID (from th= =3D e index) and immediately go into the page without doing any further calculation ...so yes, its right that the ROWID is unique for the lifet= =3D ime of the row IN THE PAGE. In an IN PLACE ALTER situation, when u update t= =3D he row it may be relocated to another page and a new rowid is representing= =3D the row now. ROWID is no internal integer which the engine increments every= =3D time a row is inserted ..ROWID is the means for the engine to reach the= =3D row in the quickest possible way ... HTH Thanx much, Rajib Sarkar Advisory Software Engineer (RAS) IBM Data Management Group If we all did the things we are capable of doing, we would literally astound ourselves. -- T. Edison = =3D "Jean Sagi" = =3D <jeansagi@myrealb = =3D ox.com> = =3D To Sent by: ids@iiug.org = =3D forum.subscriber@ = =3D cc iiug.org = =3D Subj= =3D ect Are rowids always in increasing = =3D 04/22/2004 04:13 order? [2867] = =3D PM = =3D = =3D = =3D = =3D = =3D = =3D Hi, I wonder if anyone one knows if IDS (9.3) asigns rowids in increasing order? I mean Always. In the documentation it i stated that: "The database server assigns to each row in the rowid column a unique number that remains stable for the life of the row." But I haven't found any indication that the numbers asigned to the rowd= =3D is are always choosed in increasing order. If anyone know, let me know . I'll appreciate it a lot. Chucho! Jean Sagi jeansagi@myrealbox.com jeansagi@netscape.net ----------------------------------------- =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D The information contained in this message may be privileged and confidential and protected from disclosure. If the reader of this message is not the intended recipient, or an employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any reproduction, dissemination or distribution of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by replying to the message and deleting it from your computer. Thank you. Tellabs =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D = --2__=88BBE4ECDFC14A818f9e8a93df938690918c88BBE4ECDFC14A81 Content-type: text/html; charset=US-ASCII Content-Disposition: inline Content-transfer-encoding: quoted-printable <html><body> Yes for fragmentation, rowids are not generated by default as a frag= ment internally is represented as a "seperate tablespace" and= since ROWID is a representation of the logical page offset within a pa= ge for a fragmented table rows in different fragments can potentially h= ave the same ROWID. That's why when you create the table "WITH ROW= IDS" option a special rowid index is created which has got the &qu= ot;fragment partnum, page offset and slot#" to identify the row un= iquel

↪ replying to Jean Sagi

vze2qjg5@verizon.net — Fri, 23 Apr 2004 15:53:09 — source: IIUG Forums & Mailing Lists

rowid is based on physical location of the row within the table. Should a lower page be compressed and free space become available on it, then you will get a subsequent row with a lower rowid. cheers j. > > From: "Jean Sagi" <jeansagi@myrealbox.com> > Date: 2004/04/22 Thu PM 06:13:08 CDT > To: ids@iiug.org > Subject: Are rowids always in increasing order? [2867] > >

Glossary

IDS (Informix Dynamic Server)