[PERFORM] select on index column,why PG still use seq scan?

I create a table and insert some items. I create index on every column. And I execute select, I thought it should use index scan, but it is still seq scan. Why PG do not use index scan? create table v_org_info( org_no varchar2(8), org_nm varchar2(80), org_no_l1 varchar2(8), org_nm_l1 varchar2(80)

[PERFORM] why after increase the hash table partitions, tpmc decrease

We use benchmarksql to start tpcc test in postgresql 9.3.3. Before test we set benchmarksql client number about 800. And we increase the hash partitions from 16 to 1024 , in order to reduce the hash partition locks competition. We expect that after increase the number of partitions, reduces lock