Re: the explain of tbcheck -pt

jjdai@hotmail.com wrote: . . . . snipped . . . > Hi John , > Thanks for reply , I got a clear understanding from your reply , > I think you are a practical DBA of informix , is your daily work to > maintain your informix or to develop applications . Both. We use 4GL as our programming language of choice. > > By the way , I still want your help , > > Is there any limitation of the number of extents for a table ? I > heard that if the number of extents for a table exceed 8 , the > performance will down quickly . how about your viewpoints ? There probably is a hard limit somewhere, but I haven't found it. I start thinking about reorging my data at about 5 to 8 extents. > > If I do a dbexport and drop the database and then do a dbimport , > will the number of extents for each table become to only one , > or is there any other methods to defrage the extents to improve the > performance ? That could do it. The only problem with that would be the fact that dbimport will create a table and all associated indices before it will load the table. It would be much faster to create the table, load the data, when recreate the indices. Dbexport / dbimport should take care of extent interleaving also. Of course, if your database is smaller, then dbexport/dbimport would be the quickest way to go. John Carlson Informix DBA WH Smith, Inc.