title: What does (+) mean in SQL?
body: <p>What does the (+) mean in the Where Clauses in this SQL statement?</p>
  
  <pre><code>SELECT  p.FIRSTNAME,
          p.LASTNAME,
          p.LOGINNAME,
          a.DESCRIPTION,
          a.PERIPHERALNUMBER,
          a.SUPERVISORAGENT,
          t.ENTERPRISENAME,
          t.DIALEDNUMBERID,
          sp.FIRSTNAME AS SUPER_FIRSTNAME,
          sp.LASTNAME AS SUPER_LASTNAME,
          sp.LOGINNAME AS SUPER_LOGINNAME,
          sa.PERIPHERALNUMBER AS SUPER_PERIPHERALNUMBER,
          sa.SUPERVISORAGENT AS SUPER_SUPERVISORAGENT,
          a.SKILLTARGETID,
          a.PERSONID,
          t.AGENTTEAMID,
          sa.SKILLTARGETID AS SUPER_SKILLTARGETID,
          sa.PERSONID AS SUPER_PERSONID
  FROM    C2O.AGENT a,
          C2O.PERSON p,
          C2O.AGENT_TEAM_MEMBER tm,
          C2O.AGENT_TEAM t,
          C2O.AGENT sa,
          C2O.PERSON sp
  WHERE   a.PERSONID = p.PERSONID
  AND     a.SKILLTARGETID = tm.SKILLTARGETID(+)
  AND     tm.AGENTTEAMID = t.AGENTTEAMID(+)
  AND     t.PRISUPERVISORSKILLTARGETID = sa.SKILLTARGETID(+)
  AND     sa.PERSONID = sp.PERSONID(+)
  AND     a.DELETED = 'N'
  AND     p.LOGINENABLED = 'Y'
  AND     SUBSTR(a.PERIPHERALNUMBER,2,3) = 580;
  </code></pre>