Lentitud Firebird

[mjjj]

hola en hacer el siguiente codigo demora 20 segundos.

Código Delphi [-]
F_NVAOC.ibdataset1.close;F_NVAOC.ibdataset1.selectsql.clear;F_NVAOC.ibdataset1.selectsql.add('select noc, empresa from compras');F_NVAOC.ibdataset1.selectsql.add('where empresa='+quotedstr(empresa));F_NVAOC.ibdataset1.selectsql.add('order by noc desc');F_NVAOC.ibdataset1.Open;noc:=F_NVAOC.ibdataset1.fieldbyname('NOC').asinteger;F_NVAOC.ibdatase  t1.append;F_NVAOC.ibdataset1.fieldbyname('EMPRESA').asstring:=empresa;F_NVAOC.ibdataset1.fieldbyname  ('NOC').asinteger:=noc+1;F_NVAOC.ibdataset1.post;form1.IBTransaction1.COMMIT;

Esta bien eso... o demora mucho??