Anomaly: How are pages allocated?

I'm using On-Line 7.31.UC6. Am trying to reclaim unused space from a DB and to do this I'm trying to understand the Sysmaster DB. I'm going to unload a very big table (t_invoices_ar ~ 17M rows used, 50M deleted by me), drop it, rebuild it, and then reload it. To test my scripts I created a table, t_invoices_ar_temp, and then ran the scripts on that using a 200 row subset of the big table. Everything looks good. About an hour later, doing some investigating, I used this script: select tabname,ti_nptotal,ti_npused,ti_npdata,ti_nrows,ti_rowsize from systabnames, systabinfo where partnum = ti_partnum and dbsname = 'hutrep_eom' and tabname like 't\\_%'; And got this output: tabname ti_nptotal ti_npused ti_npdata ti_nrows ti_rowsize t_invoices_ar 3623517 3623517 550193 17606143 59 t_invoices_ar_dia 8 1 0 0 31 t_invoices_ar_vio 8 1 0 0 72 t_oone_calltype 8 5 4 62 120 t_invoices_ar_temp 136563 17 7 200 59 t_invoices_tmp_dia 8 1 0 0 31 t_invoices_tmp_vio 8 1 0 0 72 t_equipshist 176 170 85 2018 78 t_invoices 145149 102731 80130 2724388 55 t_phone_rev 13960 13949 7036 379929 33 I understand this to mean that t_invoices_ar_temp has been allocated 136,563 pages but only 17 are in use!! There has been no activity Either I totally misunderstand this output or there was a been a very worrying, massive overallocation of pages to this table or there is third, very mysterious explanation. Can anyone help me to understand what is happening here? Thanks, Chris Bullivant