Suggestions to improve the INSERT performance

Question

Hi All,
I have a table which has 170 columns .
I am inserting huge data 50K and more records into this table.
my insert would be look like this.
INSERT INTO /*+ append */ REPORT_DATA(COL1,COL2,COL3,COL4,COL5,COL6)
SELECT  DATA1,DATA2,DATA3,DATA4,DATA5,DATA5 FROM TXN_DETAILS
WHERE COL1='CA';
Here i want to insert values for only few columns.Hence i specifies only those column names in insert statement.
But when huge data(50k+) returned by select query then this statement taking   very long time to execute(approximately 10 to 15 mins).
Please  suggest me to improve this insert statement performance.I am also using 'append' hint.
Thanks in advance.

Answer 1

a - Disable/drop indexes and constraints - It's far faster to rebuild indexes after the data load, all at-once. Also indexes will rebuild cleaner, and with less I/O if they reside in a tablespace with a large block size.
b - Manage segment header contention for parallel inserts - Make sure to define multiple freelist (or freelist groups) to remove contention for the table header. Multiple freelists add additional segment header blocks, removing the bottleneck.  You can also use Automatic Segment Space Managementhttp://www.dba-oracle.com/art_dbazine_ts_mgt.htm (bitmap freelists) to support parallel DML, but ASSM has some limitations
c - Parallelize the load - You can invoke parallel DML (i.e. using the PARALLEL and APPEND hint) to have multiple inserts into the same table. For this INSERT optimization, make sure to define multiple freelists and use the SQL "APPEND" option. If you submit parallel jobs to insert against the table at the same time, using the APPEND hint may cause serialization, removing the benefit of parallel jobstreams.
d - APPEND into tables - By using the APPEND hint, you ensure that Oracle always grabs "fresh" data blocks by raising the high-water-mark for the table. If you are doing parallel insert DML, the Append mode is the default and you don't need to specify an APPEND hint. Also, if you're going w/ APPEND, consider putting the table into NOLOGGING mode, which will allow Oracle to avoid almost all redo logging."
insert /*+ append */ into customer values ('hello',';there');
e - Use a large blocksize - By defining large (i.e. 32k) blocksizes for the target table, you reduce I/O because more rows fit onto a block before a "block full" condition (as set by PCTFREE) unlinks the block from the freelist.
f - Use  NOLOGGING
f - RAM disk - You can use high-speed solid state disk (RAM-SAN) to make Oracle inserts run up to 300x faster than platter disk.