Posts Tagged ‘lessons learned’

My Oracle certifications what-ifs and lessons learned: have good skills and you’ll not need luck

My takeaway from the Big Data course “Data processing systems” I was blogging about is passing the course exam and reusing the knowledge for an Oracle certification.

I passed course exam in the end of December and I had a month till the next semester and I decided to use it for additional learning to apply for Oracle certification Oracle Big Data 2017 Certification Implementation Specialist.

I will return to Big Data topic when I have the next Big Data course in following semesters. This semester my challenges are

  • Data warehousing
  • Statistics.

I hope to start blogging about them soon.

Meanwhile in this blog entry may I share some my lessons learned from Oracle certifications,

they have about 200 different certifications in 10 categories. You can browse:

–Certifications and exams required (NB: combinations available)

–Exams and what certification this exam is useful for

I have done four (I know a guy holding 32) and it makes me think I have some things to say about the process. I have

Credentials are granted based on a combination of passing exams, training and performance-based assignments, depending on the level of certification.

Oracle has a good marketing:

  • “Get the job you want – earn an Oracle Certification”
  • “86% of hiring managers surveyed say that IT certifications are a priority during the candidate evaluation process” etc.


How to choose from exam set?

It depends on

  • your plans towards certification path
  • value (eg passing the exam 1Z0-071 suits for 4 certifications!)
  • project requirements
  • your new job or career change dreams (I did is several years ago and I know my OCA certificate was the trump when I, at that time Informix developer, was confirmed at my current Oracle expert position)
  • your current skills (why not go for some ‘done’? – I do that a lot)
  • Oracle environment available
  • Oracle versions covered in exam
  • exam price
  • accessibility (proctored (classroom)/non proctored (online))
  • exam length and passing score
  • for fresh exams there might be less training materials available
  • your attitude and readiness to learn and challenge yourself (I do that a lot)

If exams are similar, then search like : ‘1Z0-071 vs 1Z0-061’ etc. I usually choose the hardest one to learn more.

Some time ago SQL was only a tool for me. Like hammer, partially because I was working in Informix and had no feeling I can do miracles in SQL and Informix SPL (apologies for liking Oracle SQL and PLSQL better).

Little by little I realized I want more and decided to study Oracle in parallel to get ready for changing job profile. I read about the Order of the Wooden Pretzel, inspired by the famous Steven Feuerstein quote “SQL is not a complete language. Some people can perform seeming miracles with straight SQL, but the statements can end up looking like pretzels created by someone who is experimenting with hallucinogens”. To prove that, international SQL challenges were held and winner becomes Knight of the Order of the Wooden Pretzel.

May the quickest, most entertaining, most educational, most creative, and somewhat readable solution prevail!

In recognition that SQL is not the only language in which enterprising developers can create pretzels on hallucinogens, the challenge is also open to NoSQL solutions. Well, it seems this has been put on hold for a while but maybe I was not googling long enough.


Oracle strongly prohibits cheating

You sign an agreement before exam (example – including

Bad news:

  • you can accidentally stumble into brain dumps forums/topics (and you may not even know they are…) – just be aware
  • practice tests you buy might appear attractive wrapped dumps

Good news:

  • authorised practice tests available for most exams (but not for all, for example, Big Data exam does not have).

Some characteristics of the exams in SQL and PLSQL:


Exam day

  • Shortly: pay for exam and book time via PearsonVUE in BDA
  • Read confirmation email what you need to bring with you
  • Note, you must have TWO person documents with you:
    • passport and driver licence, for example
  • Arrive ~20 mins earlier (there is coffee and cookies in BDA)
  • You will be photographed AND face will be compared to previous exams if any (so might be several photos taken until matches)
  • You will place all belongings in a lockable wardrobe
  • They’ll give
    • a special pen like marker
    • 1-2 sheets of laminated A4 paper (depends on exam); you may not erase your notes
    • ear plugs
  • You will be guided to a computer room and set until you see [Start test]
  • You will be videomonitored all the time
  • You may leave the room to WC, time is not stopped

Exam software

Before starting exam you have option to choose intro.

Interface changes between versions but the idea stays the same:

  • Question content (may be with [Exhibit] or [View] buttons for popups)
  • Answer options – radio buttons or checkboxes
  • Checkbox [Mark] for later review
  • Buttons [Previous] and [Next] – you always can browse
  • Button [Review] (sub-options – marked ones or all)
  • Button [End exam] (you may press it any time; re-asks before quit)
  • Time counter showing how much time left like (00:46:32)
  • Question counter like ‘Question 17 of 63’

Do not leave marked unanswered question – points are not negated for qwrong answer and guessing comes for free – because exam time flies very fast.

English language, no dictionary available, no time discount.

Question types

  • May contain [Exhibit] or [View] buttons for popups, usually showing table descriptions, rarely questioned target report template
  • Radio buttons (one from four options usually)
  • Checkboxes, usually 4 to 6
    • Choose two (or three)
    • Choose all that apply
  • May contain options ‘all of above’ and/or ‘none of the above’
  • May be combined question statements and options like
    1. A-4, B-1, C-3, D-1, E-1, F-3
    2. A-3, B-4, C-1, D-1, E-1, F-3
    3. A-1, B-2, C-4, D-2, E-2, F-1
    4. A-1, B-3, C-3, D-2, E-2, F-2
    5. E. A-1, B-1, C-1, D-2, E-1, F-3

After exam

    1. You will be given a printout that your results will be available online within in about 30 min
    2. Usually there are within 10 minutes (if you have issue with CertView account you can some hours later call Oracle support and by your testing ID they will tell results by phone)


  • Earlier they used to send printed Certificates and cards but now are saving environment and does not send
  • You will receive emails. Approx 10 minutes after exam –  about availability of results, about 24 hours later about e-certificate and about 48 hours later about badge in Acclaim.


Associate level certification


Professional level certification



Learning – what?

    • I found Gints Plivna blog to be very useful, especially NULL:
    • Stay real and stay calm. Don’t try to memorize REGEXP
    • Enjoy the process and have fun
    • I subscribed to various a la ‘Daily SQL challenge’
      • in LinkedIN
      • via email
    • To SQL, PL/SQL groups in LinkedIN and Facebook

Learning – how?

    • Despite experience it takes time, if you target to add value for yourself
      • depends on experience. Eg, OCA about a month daily 1-2 hours
      • read topic by topic in manuals
      • play a lot in Oracle
      • google pros, cons, examples
      • drill practice test
    • Set mindset to do exercises and daily tasks correct at once
    • Consider buying practice tests and drilling daily by portions
    • Remember: passing score is never 100%! You MAY afford to have mistakes
      • Helpful: fast recognising of obvious errors to lessen options
      • Questions containing functions may serve as hints for others (like syntax of NVL2 or TO_CHAR or SUBSTR)
    • Internet full of incorrect examples and wrong answers, so it is crucial to distinguish right from wrong and test, test, test
    • if this is not Oracle page and there is a question and answer like ‘Correct: B’ without explanation it sounds stolen dump – be aware
    • often accompanied with note ‘any fool can see that correct is B’Many people enjoy writing blogs about preparation, I was reading them also.







Practice tests – see

Oracle Database 11g: SQL Fundamentals I 1Z0-051

(it was easier then real exam)

30 days online access

99 $



Oracle Database 11g: Program with PL/SQL 1Z0-144 30 days online access

99 $



Oracle Database 11g: Advanced PL/SQL 1Z0-146

(again – it was easier then exam)

30 days online access

99 $



There are plenty of practice tests if you google. Remember: You sign agreement to not use unauthorised materials

– Practice Exam:Oracle authorized practice exam from Transcender

Examples of challenges




  • There is always a chance something you do not know appears
  • There might be questions like ‘what is the 3rd parameter of DBMS_RLS.REFRESH_GROUPED_POLICY’
  • And, eg, which of the answers can be produced by a specific built in package (DBMS_REDEFINITION, DBMS_HPROF, DBMS_LOB, UTL_COLL etc)
  • Don’t panic – your background is good enough to do a good guess. Remember, you may afford to have mistakes

And, after all, even failing is not the end or world. Very many people fail. One of my friends passed PLSQL exam in 4th try.

Good skills and good luck!


Big Data has sent you a friend request. Accept or Ignore?

Do you know there is a continuing education program – Big Data analytics Lielo datu analītiķa modulis – tālākizglītības iespēja IT profesionāļiem in Latvian University Computer Science faculty? Moreover, this program was introduced in cooperation with Accenture Latvia as a subprogram from Computer Science master studies.
Moduļa izveide ir Accenture Latvia iniciatīva un nepieciešamība pēc tālākizglītības iespējām esošajiem darbiniekiem.”

I will drop in here sometimes to reflect on my journey and lessons learned.

Why am I there?

Because I want to learn. I am relational databases and SQL expert and I hope as well map my current skills as to improve in Big Data area. I believe we have no choice to turn away and pretend Big Data do not apply to us. At the moment, less than 0.5% of all data is ever analyzed and used, just imagine the potential here.

After all this is so interesting turn in existence of mankind how have we faced that greedy data burst over us and I have chosen to domesticate that big data beast instead of fearing AI will steal my job.

Am I scared of lack of capacity? Of course, I am! Do I have plenty of free time? Oh, you can trust me, full time developer and mother-of-three and servant-of-three-cats, I haven’t! This is a very complex and time consuming program, I must attend and pass exams for six courses within 2 years from statistics to predicting algorithms, from Hadoop to R and neural networks. Each lecture lasts 16:30 – 19:45 (heyahh, nearest Narvesen, are you ready to sell a lot of coffee?). This semester once a week, next semester – twice a week.

I saw this year we are about seven newbies – wannabe big data analysts from various IT companies there. Let’s see survival rate. Fingers crossed for all of us!

So, I attended
the first lecture
of possibly the easiest course of six in total – Data processing systems. Professor tempts us with benefits of completing this module and uses a lot of buzzwords – NoSQL, HADOOP, ACID, BASE, CAP theorem, map reduce etc. We will have tests, quizzes and practice to set our system on our choice. Professor also reveals that previous year students ran restaurant’s and fitness clubs in their deliverables. Also, he will randomly pair students to force their systems integration. We will have to use our fantasy – like restaurant menu to be accompanied with a personalised offer from fitness club for best burn calories eaten.

Professor in action

He jokes we will experience a common real life situation when MY system is perfect and that terrible pain when you need to integrate that MY very perfect one with this totally horrible ‘other system’.

After intro about course prerequisites etc we had a warm-up session to illustrate why there is an explosive demand of Big Data analysts. By the year 2020, about 1.7 megabytes of new information will be created every second for every human being on the planet. Accumulated digital universe to around 44 zettabytes or 44 trillion gigabytes.

Why do we have data amount increasing so fast?

I bet you can’t even imagine all the different ways there are for data to be collected – some to be used right now for a known purpose and much of them are accumulated to reveal their potential later (like Facebook finds more and more ways to use their fabulous data collection) and most likely to use as a basis to be fed into artificial intelligence.

XKEYSCORE is a formerly secret computer system first used by the United States National Security Agency for searching and analyzing global Internet data, which it collects on a daily basis. The program’s purpose was publicly revealed in July 2013 by Edward Snowden. Content for 3 to 5 days and metadata for 30 to 45 days tracking someone’s Internet usage as easy as entering an email address. The amount of data per day is 20+ terabytes.

Creative businesses like Turnstyle are gathering location data from the pings and signals smartphones are giving off when Wi-Fi or Bluetooth is turned on. To track that consumer’s exact path and timing, do they linger by the shoe rack and after that decide to head to espresso bar. These data are sold – isn’t it nice to see where people are crowding or avoiding?

Browsers, applications, smartphones, smartwatches, wearable devices, vacuum cleaners and lawn movers, fridges and car navigation systems – all they are sending data to their base station. Amount of devices and users is growing very fast.

Video cameras and drones, car recorders and health checks, robots for cleaning oil pipelines, buyer’s habits in supermarkets and student’s grades, taxes and account operations, selfies taken and emails sent, phone calls and google searches, Candy Crush moves and self-driving cars, augmented and virtual realities…

Everywhere around is data and data about data. If we do not use them to make our lives better right now, we are wasting that data resource, letting their power to stay idle and downtime.

Challenges humans face

  • How to learn to use this tremendous amount of big data?
  • How to extract value from big data? Imagine a doctor’s office having stream of his patient heart rate, oxygen level and hundreds of other measurements. How to detect anomalies in data and trigger his attention?
  • How to know what value can we extract from big data we have? (remember TurnStyle and consumer path from wifi; remember Facebook anniversaries greetings…)
  • How to search within big data? (remember a sad story when a path was restored based on a small shoe fragment in one of camera recordings)
  • How to store big data?
  • How to update big data?
  • And, of course, quite painful issue of data protection. International Data Corporation IDC estimates that about 40% of data requires some level of security, from privacy protection to full-encryption “lockdown.” Unfortunately, from these 40% less than a half actually has protection.

This blog is solely my personal reflections.
Any link I share and any piece I write is my interpretation and may be my added value by googling to understand the topic better.
This is neither a formal review nor requested feedback and not a complete study material.

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