Category Archives: Java/Java EE

[2018 oracle code one] hands on lab JNoSQL

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Hands on Lab: Eclipse JNoSQL: One API to Many NoSQL Databases

Instructors: Leonardo Lima, Otavio Santana, Senior Software Engineer, Hillmer Chona, Patricia Uribe & Jonathan Vila Lopez

For more blog posts, see The Oracle Code One table of contents

Lab URL: https://github.com/JNOSQL/oc1-hands-on-2018

Overview of NoSQL

  • No fixed data structure
  • not ACID
  • BASE -Basically Available, Soft State, Eventual consistency
  • Five types
    • key/value – Redis, Hazelcast, Couchbase
    • column family – Hbase, Cassandra
    • document – Couchbase, MongoDB, Riak
    • graph – Neo4J
    • multi-model – OrientDB, Couchbase
  • From most scalable/least complex to least scalable/most complex – Key/value, column family, document, graph

JNoSQL

  • First Jakarta EE specification
  • Mapping API – Artemis
    • Heavily based on annotation
    • “Query by” methods
    • Inject DocumentTemplate – has CRUD methods
  • Communication API – Diana
  • Trying to replicate JDBC/JPA for NoSQL
  • Traditionally, use different API for each NoSQL type
    • BaseDocument
    • Document
    • JsonObject
    • ODocument
  • DocumentEntity/Document – for all the types
  • Working on for 2 years
  • Almost up to 1.0 version
  • Configuration is one json file

My take: I like that they brought/shared their own wifi. Good overview at the beginning. I think I missed the point of the instructions at first. It felt too freeform. But then it made sense once they started explaining the code. So either it assumed knowledge or I thought we were doing something else. (I did get it to work; I just thought we were supposed to be doing something else.) Also, there was an instructor for each 1-2 attendees. Every time I went to do something (email, Slack, pull request), someone asked me if I needed help. I was waiting for Maven/Docker, not being idle! Also, not their fault, but the improvised lab room had sun blocking the screen. Overall, I enjoyed the lab. The second exercise clicked because I understood what we were doing!

[2018 oracle code one] beyond git add/commit/push

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Beyond git add/commit/push
Speaker: Jorge Vargas and Victor Orozco
@edivargas and @tuxtor

Full deck: http://www.jorgevargas.mx/wp-content/uploads/2018/10/Git-SCM-en-v5.pdf

For more blog posts, see The Oracle Code One table of contents

Review

  • add – puts in to staging area (from working directory)
  • commit – puts in local repo
  • push – puts in remote repo
  • reset hash – override working directory with local repo
  • fetch – get from remote repo to local repo
  • pull – fetch + merging into your local branch
  • clone – get from remote repo to working dir

Workflow

  • select a workflow – varies by project, but all team members should know what using
  • Common workflows
    • Centralized – all commits to master. Usually for new git users.
    • Feature branch – do feature in a branch and then merge in.
    • Gitflow – do changes in branch and merge into develop. Then merge development into master. Only commit to master for hotfixes or when develop ready for release
    • Forking – copy of repo and merge in
  • Recommendations
    • No one workflow to rule them all.
    • Code in master should be complete and functional at all times
    • Create short lived branches
    • Use meaningful names for branches

Advanced Git commands

  • stash – a quick save of your working directory

Demo

  • git init – to create repo
  • git status – showed file in staging area
  • git commit – add file
  • Edit .gitignore – to omit .class files
  • git log – see actual commit
  • git log –oneline –graph –all – list commits one line per commit so easier to read. Shows which branch the change is in
  • git checkout -b newBranch – create new branch and switch to it
  • git branches – list all branches
  • git checkout master – switch to master
  • git checkout -b branch2 – create a second branch off master
  • git merge newBranch – first merge smooth
  • git merge branch2 – created merge conflict. Fix manually
  • git branch -d newBranch – delete branch

My take: I had trouble understanding their accents at first, but then it got easier. The content itself was good. I was also a little distracted getting ready for my session next. I like that they did a live demo. I thought the content was going to be more advanced. The mention of stash was a good one. But then the demo was easy. To be fair, a bunch of people in the room didn’t raise their hands for using git. They got to the advanced part right when they ran out of time. I look forward to reading the rest of the deck at least.

 

 

[2018 oracle code one] graph databases

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Let’s Make Graph Databases Fun agan with Java
Speaker: Otavo Santana & Elder Moraes
Tomitribe & Oracle

For more blog posts, see The Oracle Code One table of contents

Sematics

  • Web 3.0 – More interaction between machines
  • Search JCP. Get JC Penny vs Java Community Process
  • Search Ajax. Get cleaner, technology and soccer team

Relationships

  • Link pieces of data
  • Having metadata on relatioships is useful. (Ex: reason for travel, not just that does travel)

NoSQL (not only SQL)

  • Doesn’t use structure or transactions
  • Five diferent types – key/value, columns, document, graph, hybrid of multiple types
Term Key/value Columns Document Graph
Table Bucket Column Family Collection N/A
Row Key Value pair Column Document Vertex
Column N/a Key/value pair Key/value pair Vertex and edge property

 

  • CAP – consistencyy, availability, fault tolerance
  • Graph – neo4j, infogrpi, sones, hybergraphdb
  • Apache TinkerPop  like JDBC – try to standardize database interaction
    • Can add edge/verfix
    • has()  – like where cause
    • OutE() – edges
    • BothV() – reurn both ends of relationship
    • repeat/times – repeat action mltiple times to go through graph
    • repeat.until – repeat action until condition is true
  • JNoSQL – mapping/communication API. Like  a demo. Maps to Java object

My take: I learned a lot at this session! I really like the comparison of different database types and terms. I also liked the build up of queries and the Noe4J demo