Category Archives: Databases

Learning GO: Obtaining a unique sequence from #PostgresSQL with #golang

At some point I discovered GO trying to do very simple and fast code for specific tasks without having to load lots of libraries, deploy application servers or set up complicated frameworks. If you want to build fast very small native micro-services that can be deployed in a docker instance < 10MB Go is the… Read More »

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Investigate #Oracle #deadlocks

Sometimes we may end up having some application resources competing for the same resource on our Oracle database. This is usually the case when some exclusive resource must be allocated or updated as in the case of database based locking mechanisms. If there are code issues we may end up in a deadlock situation when… Read More »

Drop a not null constraint with #SQL

Sometimes very annoying things can be removed with a simple SQL commands which nobody remembers because is used so rarely. For example when we have to update a database schema and remove a not null constraint on a column. There is a short one liner for it:

Optimizing DELETE operations on big tables in #DB2

Deletes go very slow if the log buffer size is too small and we delete lots of data from big tables. It is very important to have the right settings for log buffer size to avoid having to frequent writes to the disk, writes that cause a high IO traffic that will slow down the… Read More »

XA datasources with #WebSphere and #Oracle

When using XA data sources with Websphere and Oracle we must grant to the Oracle user rights to perform XA recovery. STEP 1: Create an XA datasource

STEP 2: Grant right to the oracle user (MY_USER). As sysdba execute the following: Grant access to pending transactions.

Grant access rights to distributed transactions awaiting… Read More »

#Oracle 12c invisible columns

“Invisible columns”: This is a new feature introduced in Oracle 12c that got me all excited. In short you can now have hidden columns in a table that are not visible to the standard SELECT, INSERT clauses if you do not want to. Some usage for this: Legacy application queries I hate how you have… Read More »