Comments for An Expert's Guide to DB2 TechnologyChris is a DB2 for Linux, UNIX and Windows lifer having worked at IBM on DB2 since its inception. Follow along as Chris shares his experiences and provides tips and techniques for getting the most out of DB2 including how to exploit new features and releases as they come on-line.Comment by Chris Eaton on Large Tablespaces the default in DB2 9- September 16, 2008 Hi iisdjp, thanks for the comments...some times it feels that way :-) Don't be embarrassed...no question is too simple (in fact this is not a simple answer). The number of entries in an index (and in fact number of rows in a data table) vary depending on the data. So for example if I index a CHAR(80) column where every row is unique then the index will have the key value and one rid for each entry, which would be an 8http://networking.ittoolbox.com/r/rss.asp?url=http://it.toolbox.com/blogs/db2luw/large-tab... Comment by Chris Eaton on DB2 Recovery Basics - Part 1- September 16, 2008 Hi Slim, If you restore an image into a new database then it will use the parameters from the backup image. However, if you first create a database on test and then restore the image into that database then it won't overwrite the parameters. Here is more information on restoring into and existing database. !! Entry Link: a href="http://networking.ittoolbox.com/r/rss.asp?url=http://it.toolbox.com/blogs/db2luw/db2-recov... Comment by Chris Eaton on Converting Regular Tablespaces to Large Tablespaces in DB2 9- September 16, 2008 Hi Mikhail, A RID (which stands for Row ID) is really just a pointer to a row. It is composed of a page number and then a slot within the page. So the number of RIDs "in use" is equal to the number of rows in the table (since each row has only 1 rid). OK that's not 100% true because it's possible to have overflow records but for now lets just say that it's close enough. So it doesn't equate to npages or fpage. Which are the number of pages allocated to the table and the number of pageshttp://networking.ittoolbox.com/r/rss.asp?url=http://it.toolbox.com/blogs/db2luw/convertin... Comment by Chris Eaton on OLAP SQL Part 1 - Rollup- September 16, 2008 Hi Ravi, Absolutely correct! Every page is associated with one and only one table. So rows on any given page are for a single table only. !! Entry Link: OLAP SQL Part 1 - Rollup!!http://networking.ittoolbox.com/r/rss.asp?url=http://it.toolbox.com/blogs/db2luw/olap-sql-... Comment by durbha on OLAP SQL Part 1 - Rollup- September 16, 2008 Chris: In this post you mention that we could also display table sizes by multiplying the pagesize with npages. My question is : "Do we assume then that DB2 does not interleave rows from multiple tables on a single page" Ravi. !! Entry Link: OLAP SQL Part 1 - Rollup!!http://networking.ittoolbox.com/r/rss.asp?url=http://it.toolbox.com/blogs/db2luw/olap-sql-... |