Re: create index on table with blobs

In article <69j72m$783@snews2.zippo.com>, Dagmar und Roland Wartenberg <dagmarw@wartenberg.mannheim-netz.de> writes >Hi all, > >perhaps there is anyone here who could help me to find >a solution for this problem. > >In an ODS 7.23UC4 we have defined a table with the following >colums: > >mandt char(3) >relid char(2) >srtfd char(30) >srtf2 decimal(10) >clustr decimal(5) >clustd byte > >The table is fragmented by round robin, 16 x 2 GB alloc.; >currently it has about 80.000 rows and >it has an index on (mandt,relid,srtfd,srtf2). > >As you can see the field clustd is declared as byte, >so this table will contain blobspace (but the table >is located in a normal dbspace). > >Now comes our problem: > >When we try to create the index on this table using >PDQ functionality, the process doesn't work parallel >at all. It does a sequential table scan, each fragment >alone. The time to create the index is about 16 min. >But: When we create a second table with the same columns >and copy all the data from the first to the second table, >but not the data in the clustd byte ("insert into >tablenew(mandt,relid,srtfd,srtf2,clustr) select >mandt,relid,srtfd,srtf2,clustr from tableold"), >and if we create the same index on the second table, >then all works fine. The fragments will be scanned >in full parallel access, and the index will be created >in about 10 seconds. >(By the way, PSORT_NPROCS, PDQPRIORITY and all other >important environment variables are set correctly.) > >So, can it be, that the PDQ functionality doesn't work >for a table containing blobs? Or, if someone here knows >how it works (special parameter, environment variables,etc.) >please give me a tip. Please answer via email to >rolandw@wartenberg.mannheim-netz.de. > > >Regards, >Roland > > Certain things do NOT generate multiple threads - Corelated subqueries - Queries run with cursor stability I would expect that blobs have the same effect. Try shift the blobs into a blobspace i.e. separate them from the table. > > -- David Williams Maintainer of the Informix FAQ Primary site (Beta Version) http://www.smooth1.demon.co.uk Official site http://www.iiug.org/techinfo/faq/faq_top.html I see you standin', Standin' on your own, It's such a lonely place for you, For you to be If you need a shoulder, Or if you need a friend, I'll be here standing, Until the bitter end... So don't chastise me Or think I, I mean you harm... All I ever wanted Was for you To know that I care