[GENERAL] Lock during insert statement

[AI Rumman]

Could any one please tell me why my system is waiting to get lock for an
INSERT statement?

2014-05-21 07:52:49.965 PDT [9-1]LOG:  process 31407 acquired ExclusiveLock
on extension of relation 429298276 of database 21497 after 3219.963 ms
2014-05-21 07:52:49.965 PDT [10-1]STATEMENT:  INSERT INTO table1
(end_id,account_id,create_time,event_type,details) VALUES($1,$2,$3,$4,$5)
2014-05-21 07:52:49.965 PDT [3-1]LOG:  duration: 4590.048 ms  execute
<unnamed>: INSERT INTO table1
(end_id,account_id,create_time,event_type,details) VALUES($1,$2,$3,$4,$5)


Thanks.