There are times when we need to find which are the tables that depend on a given table. This is useful when cleanup or archiving jobs have to pe performed and the interconnection of constraints is becoming a nuisance. Lucky for us in the case of Oracle database is quite simple to search through all… Read More »
Reinstalling things like Oracle is always a hassle and takes about one day to make it work. Lucky for me I made a full back-up of my old disk when I upgraded to a new laptop. On the new laptop I did a fresh install of Fedora 28. The idea is to migrate my old… Read More »
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 »
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 »
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: ALTER TABLE my_table ALTER COLUMN name DROP not… Read More »
It looks like the Microsoft SQL Database Mirroring a feature I used a lot and for which posted a step by step tutorial that proved to be very popular was deprecated by Microsoft. In a news article on Microsoft site the alternative is presented “Basic Availability Groups (Always On Availability Groups)”. I will summarize in… Read More »
DELETE operations are much faster in case we disable constraints. This is because not all foreign keys affected by the DELETE are indexed. We have to detect all the foreign keys that point to the table from where you delete data. The we can create temporary indices to help speed up the delete. STEP 1.… Read More »
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 »
After migrating my full DB2 backup (binaries and data) to a new server I got into several issue. One was already described in the previous post here. ISSUE: Even after fixing that start issue I was still not OK. My WebSphere data source that linked to the DB2 instance was not responding. Trying to ping… Read More »
I moved my DB2 installation to a new server from a full back-up. After performing all the necessary steps: 1. Recreate the necessary users: db2inst1, db2fenc1, db2das1 2. Give ownership to their home directories ISSUE: I tried to start the instance. I logged in to the db2inst1 user and started the database. This was the… Read More »