help

hi i have a database it was running but i ignored it so yes i deserve to die
it was running fine but now it chews all cpu through postmaster is there a
way to delete the information contained in tables
 +------------------+----------------------------------+----------+
 |  Owner           |             Relation             |   Type   |
 +------------------+----------------------------------+----------+
 | ispdb            | acl                              | table    |
 | ispdb            | acl_adminname_key                | index    |
 | ispdb            | actions                          | table    |
 | ispdb            | actions_pkey                     | index    |
 | ispdb            | actionsall_key                   | index    |
 | ispdb            | bringups                         | table    |
 | ispdb            | bringups_by_userid               | index    |
 | ispdb            | bringups_pkey                    | index    |
 | ispdb            | gst                              | table    |
 | ispdb            | gst_pkey                         | index    |
 | ispdb            | invoice                          | table    |
 | ispdb            | invoice_pkey                     | index    |
 | ispdb            | joinrequest                      | table    |
 | ispdb            | joinrequest_pkey                 | index    |
 | ispdb            | logins                           | table    |
 | ispdb            | logins_pkey                      | index    |
 | ispdb            | mailalias                        | table    |
 | ispdb            | mailalias_alias_key              | index    |
 | ispdb            | mailalias_pkey                   | index    |
 | ispdb            | maxnums                          | table    |
 | ispdb            | netservers                       | table    |
 | ispdb            | onlineusers                      | table    |
 | ispdb            | plantype                         | table    |
 | ispdb            | plantype_pkey                    | index    |
 | ispdb            | prepaidhours                     | table    |
 | ispdb            | prepaidhours_pkey                | index    |
 | ispdb            | retiredusers                     | table    |
 | ispdb            | retiredusers_pkey                | index    |
 | ispdb            | supservices                      | table    |
 | ispdb            | supservices_pkey                 | index    |
 | ispdb            | usagesummary                     | table    |
 | ispdb            | usagesummary_pkey                | index    |
 | ispdb            | userbilling                      | table    |
 | ispdb            | userbilling_pkey                 | index    |
 | ispdb            | userprofile                      | table    |
 | ispdb            | userprofile_pkey                 | index    |
 | ispdb            | userprofile_username_key         | index    |
 +------------------+----------------------------------+----------+
to remove all the info in the big nes
i know i am a idiot but trying to learn
thanks
stephen hardman