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Documentum – DFC traces setup & investigation

When working with Documentum, you will most probably have to enable the DFC traces one day or another and then work with these traces to analyze them. The purpose of this blog is simply to show how the DFC traces(…)

Create index CONCURRENTLY in PostgreSQL

In PostgreSQL when you create an index on a table, sessions that want to write to the table must wait until the index build completed by default. There is a way around that, though, and in this post we'll look(…)

12c Multitenant Internals: compiling system package from PDB

By Franck Pachot . When I explain the multitenant internals, I show that all metadata about system procedures and packages are stored only in CDB$ROOT and are accessed from the PDBs through metadata links. I take an example with(…)

firewalld rules for Veritas Infoscale 7.3 with Oracle

You might wonder, but yes, Veritas is still alive and there are customers that use it and are very happy with it. Recently we upgraded a large cluster from Veritas 5/RHEL5 to Veritas InfoScale 7.3/RHEL7 and I(…)

Is it an index, a table or what?

A recent tweet from Kevin Closson outlined that in PostgreSQL it might be confusing if something is an index or table. Why is it like that? Lets have a look and start be re-building the example from(…)

Unstructured vs. structured

By Franck Pachot . The title of this blog post was: "Tracing DBMS_RCVMAN for reclaimable archivelogs" until I started to write the conclusion... In a previous post I mentioned that there's a bug with archivelog deletion(…)

CBO, FIRST_ROWS and VIEW misestimate

By Franck Pachot . There are several bugs with the optimizer in FIRST_ROWS mode. Here is one I encountered during a 10.2.0.4 to 12.2.0.1 migration when a view had an 'order by' in its definition.

A response to: What makes a community?

A recent tweet of mine resulted in Martin Widlake to write a really great blog post about What makes a community. Please read it before you continue to read this. There was another response(…)

Can I do it with PostgreSQL? – 18 – Instead of triggers on views

It has been quite a while since the last post in this series but today comes the next one. Being at a customer this morning this question popped up: Can we have instead of triggers on a view in PostgreSQL(…)

Auto pre-warming in EDB Postgres Advanced Server 10

Some days ago EDB Postgres Advanced Server 10 was released and one feature which might be handy is auto pre-warming. What this does is to save all the buffers (or better a description of the buffers) which(…)