Hi,

I have rebuilt a clustered index on a sybase table that results in dropping and recreation of all the
non clustered index too. The rebuilt was sucessful ,after rebuilt to my suprise the processing of data went significatly slower which i expected to be faster, if i run some sample individual
queries on the table it is very fast as compared to before but the entire process flow(uses other tables and procedures too including this table) where it processes the data has gone down.

Is it something to do with update stattics and sp-recompile as i hadn't done that after the indexes was rebuilt.

Please advice

Yes, Please run update statistics and sp_recompile(if you're using below ASE15) and test your processing. this is becase the statistics might not been updated to use the new index.