Dear Friends, I have a table with 50 lakhs records, the table has more then 10 fields, i have primary key, i have select query with count(*) without any condition, it takes 17 seconds. I have another one query which will do joins with other small tables, it takes 47 seconds to give output, the result has 2 lakhs records. the indexing is not used. I have created one index with one field ( which i used in this query, the field value has duplicates also ). Now the cpu usage is 4.4%, and waiting for io process . i have checked the above in the top command. If i delete that index, then it works fine, now the cpu usage takes more then 70%, and waiting shows less then 30%. Can Anyone explain, Why postgres behaves like this. -- View this message in context: http://www.nabble.com/postgresql-performance-tp15847165p15847165.html Sent from the PostgreSQL - performance mailing list archive at Nabble.com. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://mail.postgresql.org/mj/mj_wwwusr?domain=postgresql.org&extra=pgsql-performance