Re: Page size limits / Columns limits

Hi all, I'm working on a project which required me to add new columns into a table which currently has 434 columns (total number of byte for one row is very high) in that table. I'm not sure whether I can add these new columns into this table since the columns size is growing. Therefore, what do you think that I need to consider before I add these new columns into the table to makesure that the performance does not deteriorated? What is the formula used to culculate total number of byte for a row in a table? as well as its page size? Thank you in advance for help. Best regards kitming Thomas Mieslinger wrote: > In 7.31 if your Tables are larger than 4 Billion rows or 32GB, then you > will have to fragment table in several DBSpaces. > > Farmer.Byrd@cfwy.com wrote: > > > > I know that in Informix 7.24 that the upper page limit per dbspace is > > roughly 16.5 million, but does the same limit hold true to version 7.31? > > > > ------------------------------------------------------------------------ > > Name: ALTERNATIVE.HTM > > ALTERNATIVE.HTM Type: Hypertext Markup Language (text/html) > > Encoding: base64 > > Description: ALTERNATIVE.HTM > > -- > Thomas Mieslinger German Parcel Paket Logistik GmbH & Co > German-Parcel-Str. 1-7 Fon: +49 6677 17 463 > 36282 Neuenstein Fax: +49 6677 17 111 > Germany Mobil: +49 170 510 6095

Low Kit Ming wrote: > > Hi all, > > I'm working on a project which required me to add new columns into a table which > currently has 434 columns (total number of byte for one row is very high) in > that table. I'm not sure whether I can add these new columns into this table The hard limits are 32767 columns and 32767 total row bytes exclusive of BLOB columns which take up only 56 bytes of row column space each. The soft limit is the number of column description entries for any variable length columns like BLOBs and VARCHARs which must fit along with the table's extent list on a single page. > since the columns size is growing. Therefore, what do you think that I need to > consider before I add these new columns into the table to makesure that the > performance does not deteriorated? What is the formula used to culculate total If you have 434 columns performance has already deteriorated, too late to worry now. However each time a row spans onto another page (2K or 4K depending on platform) performance suffers most. > number of byte for a row in a table? as well as its page size? dbschema or myschema -s will report the row size as will the dbaccess menu command table<tablname>status. Art S. Kagel Thank you in > advance for help. > > Best regards > kitming > > Thomas Mieslinger wrote: > > > In 7.31 if your Tables are larger than 4 Billion rows or 32GB, then you > > will have to fragment table in several DBSpaces. > > > > Farmer.Byrd@cfwy.com wrote: > > > > > > I know that in Informix 7.24 that the upper page limit per dbspace is > > > roughly 16.5 million, but does the same limit hold true to version 7.31? > > > > > > ------------------------------------------------------------------------ > > > Name: ALTERNATIVE.HTM > > > ALTERNATIVE.HTM Type: Hypertext Markup Language (text/html) > > > Encoding: base64 > > > Description: ALTERNATIVE.HTM > > > > -- > > Thomas Mieslinger German Parcel Paket Logistik GmbH & Co > > German-Parcel-Str. 1-7 Fon: +49 6677 17 463 > > 36282 Neuenstein Fax: +49 6677 17 111 > > Germany Mobil: +49 170 510 6095