Great MongoDb presentation from Shutterfly

Talks real numbers and real performance techniques!

http://www.10gen.com/presentations/mongosv-2011/performance-tuning-and-scalability

Tidbit:DB2: identify packages in a bind file

Use the db2bfd command to determine the names of the packages contained in a bind file:

db2bfd -b db2look.bnd    

tidbit:Oracle:identify when row was changed

Great way to identify when table row was changed (within 3 second precision):

select scn_to_timestamp(ORA_ROWSCN ) from EMP WHERE ROWNUM < 10;

tidbit:Oracle:ITL Deadlock troubleshooting and analysis

How to identify ITL deadlock:

1. Pick slot number (0x40021) at the top

2. Search for it in a deadlock trace file

3. See if wait event is ITL related.

Resolution: Increase INI_TRANS on table or on index.

                       ---------Blocker(s)--------  ---------Waiter(s)---------

Resource Name          process session holds waits  process session holds waits

TX-00040021-00001409        66    2515     X             65    1253           S

TX-0005001b-000014d8        65    1253     X             66    2515           S

    Dumping one waiter:

      inst: 1, sid: 2513, ser: 41

      wait event: 'enq: TX - allocate ITL entry'

        p1: 'name|mode'=0x54580004

        p2: 'usn<<16 | slot'=0x40021

        p3: 'sequence'=0x1409

      row_wait_obj#: 4294967295, block#: 0, row#: 0, file# 0

      min_blocked_time: 0 secs, waiter_cache_ver: 31817

Books:Book about Oracle Founder Larry Ellison

This book absolutely must read! If you are DBA or start up founder - this book opens really shocking insight how business was and is made in Silicon Valley.

Have you knew that Larry Ellison was not employee #1 of Oracle?

Have you knew that Oracle put on IPO papers that it has mainframe solution while it was not even functional?

Have you knew how exectly Oracle crush the competitors and grew sales?

Read the book!