There are various Spark Certification available as below and these very popular IT certification

  1. Databricks Spark Certification for Developer CRT020 in Scala or Python.
  2. Cloudera CCA175 Hadoop & Spark Developer in either Scala or Python.
  3. Hortonworks Spark (HDPCD) certification in scala & Python
  4. MapR Spark Developer certification in Scala only.
All above certification has equal value , respective certification importance increases when based on the company in which you are working or giving interview and which platform this company is using. 
For example if company has the Cloudera platform already deployed in production then CCA175 certification exam would be more useful and certainly have more value addition then other company certifications. Similarly if company had deployed Databricks platform in production then your Databricks Spark CRT020 certification would have more values. 
How should i compare these Company Certification with training institutes certifications?
Training institutes certification does not have that high importance because these institutes does not take any protected exam like above company and as soon as you pay the high amount of fee, you are entitled to get the certificate of training attended. It does not matter whether student learned in the training or attended training or not. Institute really does not evaluate the candidates expertise. Hence, company does not consider them until and unless you have valid certification from global companies like Cloudera, Databricks, Hortonworks, MapR etc. Even experience says, students are more grilled during the interview if they write local training institutes training.
About Global certification from above companies
As you can see in above Cloudera CCA175 certification both Hadoop and Spark would be accessed. Hence, their syllabus would be covering two wider domain. However, the level of exam difficulty is moderate and not very tough. Most of our students have score either 9 or 10 questions correctly in the real exam. They have prepared using HadoopExam CCA175 certification simulator. 
In case of Databricks main focus is on Core Spark and Spark SQL. But in depth knowledge would be evaluated. Like you should be aware minor details about the Spark framework, internal architecture of Spark framework, what all stages your job goes through when submitted on the multi node cluster etc. You must be knowing how the distributed data sharing works and much more. And all the concepts are evaluated using the multiple choice questions and answer in the real exam. Databricks CRT020 has two sections one is multiple choice exam and other is assessment (check the entire syllabus at this page). 
Databricks have not explicitly mentioned that how many questions they would be asking in the assessment, but HadoopExam experience says that in total 4-8 problem statements would be given and you need to solve them on the Databricks platform (Check here, how to solve such problem). And through this assessment exam Databricks would be accessing you knowledge , experience and efficiency in the Spark Core API, Spark SQL, SQL functions, how to use user defined functions, how to cache, uncache and checkpoint the DataFrame and Datasets etc. So mainly your programming expertise would be checked. Total exam would be for 3 Hrs.
However, Databricks had not mentioned or given any specific detail for number of questions , passing score, how much time is allotted for each section or overall time is 3 hours for both the section. (As on when we have update, we would share with you, so please be in touch with 
Regarding passing score our past experience suggests that , you score 75% marks at least in each section. So that your average score would also be 75% and you can easily clear the certification exam.
Similarly HDPCD Spark is also fully HandsOn certification exam  and you need to solve all the given problem on Hortonworks Cloud based platform. It is purely Spark framework certification exam but they are not limited to the Core Spark rather they want you to know core Spark API, Spark SQL, Spark Structured Streaming. However, you can write solution based on your choice of the programming language like Python or Scala.. hasd already helped more than 50000 learners and had proven track record since last 6 years.
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Team HadoopExam