This is an annoying issues of hibernate with DB2. Trying to add a new primitive type to an already existing entity will result in an error when updating the associated database table. As a result no update of the schema is done. Why is that ? When adding to an entity a new primitive type… Read More »
As I mentioned in a previous post I started looking into upgrading my Dell XPS 8700 see https://blog.voina.it/?p=325. One of the possibilities I mentioned there was a memory upgrade from the 16GB of the original configuration to the maximum of 32GB. By doubling the memory size I can run a 4th instance of my Fedora… Read More »
Red Hat Enterprise Linux allows administrators to bind multiple network interfaces together into a single channel using the bonding kernel module and a special network interface called a channel bonding interface. Channel bonding enables two or more network interfaces to act as one, simultaneously increasing the bandwidth and providing redundancy. The behaviour of the bonded… Read More »
As we now in case of a table with BLOBs in the actual table row only a reference to the BLOB is stored. In order to get the real table size of my table ‘MY_BLOB_TABLE’ including the refereed BLOBs the following query holds in Oracle: SELECT sum( bytes)/1024/1024 size_in_MB FROM user_segments WHERE (segment_name = ‘MY_BLOB_TABLE’… Read More »
Sometimes an oracle query goes nuts and blocks the DB. To find the blocked processes started by user MYUSER execute: SELECT s.inst_id, s.sid, s.serial#, p.spid, s.username, s.program FROM gv$session s JOIN gv$process p ON p.addr = s.paddr AND p.inst_id = s.inst_id where s.username like ‘MYUSER’; To kill the blocking process: ALTER SYSTEM KILL SESSION ‘sid,serial#’
LOBS is the DB2 way of dealing with big data. In db2 you can have a table that contains a column defined as LOB where one can dump large binary data (images, compressed text files, video or audio). The problem is the way this LOBS are stored by DB2. By default they are stored “offline”… Read More »
My desktop Dell XPS 8700 is a beast even after more than 2 years of the official release. The problem with it is that in a typical big corporate fashion it contains an unbalanced set of hardware: * A very fast processor * 16GB of memory (4x4GB so not so up-gradable to the 32GB maximum)… Read More »
There are times when a simple UPDATE or DELETE cannot be used directly on the database due to the huge amount of data stored in the table. We already covered the topic of increasing the transaction log, see post, but sometimes this is not enough. In the cases when too much data is going to… Read More »
As a big fan of the HP Microserver Gen8 (I own 3 of them in two locations) I compiled my own list of compatible hardware that I am using or used in building the servers.I have to thank the good fan forums that I always consult previous of buying new hardware for my HP Microservers… Read More »
In a setup having an enterprise application depending on a database instance where some tables are defined as nicknames to tables from a federated database, it can happen to get this very cryptic DB2 error. [12/10/15 18:06:54:895 IST] 00000073 SqlExceptionH Z org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions SQL Error: -4229, SQLState: null [12/10/15 18:06:54:903 IST] 00000073 SqlExceptionH Z org.hibernate.engine.jdbc.spi.SqlExceptionHelper… Read More »