Inserts are taking time !

[Marul Mehta]

Hi All,   We have a table which can contain more than half a million records. When we try to insert some 10k records in the empty table it get inserted in 10 min. but as the size increases time taken to insert also increases. After 350,000 records it takes around an hour to insert 10k records. There are around 15 columns in it out of which 11 are indexed. There is one concatenated function-based index on two columns of Varchar type and two separate index for the same two columns.   I have checked the free space for the tablespaces to which the table and indexes are attached to. They are in two separate tbs.   Any clues why this is happenning. TIA Marul.