Everything our consultants learn while running databases for customers: Oracle, PostgreSQL, SQL Server, MySQL, MariaDB, MongoDB and Delphix. Expect hands-on posts about installation, day-to-day administration, backup and recovery, performance tuning, replication and upgrades.
By Franck Pachot . This blog is the first one of a series about inserting 1 million rows. Do you have an idea about the time it takes? The idea came from another project, about NoSQL databases, but I’ll focus on Oracle in those posts. There are a lot of different ways to insert 1 million rows in Oracle: row-by-row…
By Franck Pachot . When you migrate, you should be prepared to face some execution plan changing. That’s not new. But here I’ll show you a case where you have several bad execution plans because lot of histograms are missing. The version is the same. The system is the same. You’ve migrated with DataPump importing all statistics. You have the…
By Franck Pachot . Want to know all your listeners – including scan listeners, and the services it listens for? It is possible from the instance, with the – undocumented – view V$LISTENER_NETWORK which is there since 11.2 Let’s look at it from a RAC database: SQL> select * from GV$LISTENER_NETWORK And here is the result: INST_ID NETWORK TYPE VALUE…
By Franck Pachot . In-Memory Column Store is amazing. It brings very good performance to full table scans. I’t easy: just ‘flip a switch’ and you accelerate all reporting queries on your table, without thinking about what to index and how. But in this post, I would like to warn you about the consequences when you just flip that switch.…
By Franck Pachot . Before going to the airport to come back in Europe, the las session I assisted at IOUG Collaborate is a panel: Nothing to BLOG About – Think Again Some famous bloggers were there to help, motivate and inspire people that are afraid to blog. The idea is good. The session was good. The panelists have shared ideas,…
By Franck Pachot . This is a very short post about something I though I had already blogged about. I like SQL Monitoring active reports. The are graphical, and still very light. There is only one thing I don’t like about it in 11g and it has been improved in 12c Look at the following. The query has run for…
This blog will present you a way to retrieve Windows Server main information via PowerShell. The goal is to be able to automate the extraction of information for different purposes: audit, report generation, dashboards… Disclaimer: I am not a developer but a SQL Server dba. If you find errors or some ways of improvement, I will be glad to…
The last post took a look at how to efficiently load 1m rows into a table in PostgreSQL. In this post I’ll take a look on how to do the same with semi structured data. Again it is the same system as in the last post using the same PostgreSQL parameters. Using the hstore datatype For storing key/value pairs there…
Franck was quite fast with his second post Variations on 1M rows insert(2): commit write. Lets see what we can do on the PostgreSQL side. I’ll take the same test table as Franck again: create table DEMO (“id” number , “text” varchar2(15), “number” number) ; The pgplsql block which corresponds to Frank’s plsql block looks like this: \timing on truncate…
When I read Franck’s post about Variations on 1M rows insert (1): bulk insert I thought doing quite the same in PostgreSQL might be interesting. Lets start by using the same test tables, one using a primary key and the other one without a primary key:create table DEMO (“id” int , “text” varchar(15), “number” int); create table DEMO_PK (“id” int…
By Franck Pachot . Yesterday I was a speaker at Collaborate15 and did my presentation about reading an AWR report. That was great. Many people (and not enough seats). Here are some aswers about questions that came later. I did that presentation at DOAG last year in a much bigger room. But because of the bigger room there was no…
By Franck Pachot . Great events like IOUG Collaborate is a good way to meet experts we know through blogs, twitter,etc. Yesterday evening, with nice music in the background, I was talking with Leighton Nelson about cloning PDB databases. Don’t miss his session today if you are in Las Vegas. The big problem with PDB cloning is that the source must…
