Migrate data from mariadb to postgres

[tilen1976]

• Properties file for postgres-local
  • Some may be helpful with Nais postgresql, but maybe not all
  • Flyway is not used
• Docker compose for mariadb, postgresql and klass-api
• Use profile spring.profiles.active=api, postgres-local, skip-indexing, embedded-solr in application.properties
• Script init-migration.sh:
  • containers are created
  • data is loaded from dump file to mariadb database
  • data is migrated from mariadb to postgresql with pgloader
  • necessary alterations on datatype 'timestamp' for removing microseconds from columns
  • Dump postgresql to file
• Script ìnit-klass-api.sh`:
  • Depends on init-migration.sh
  • Run if you want to test postgresql with klass-api
  • Klass api container is created in init-migration.sh, but application will stop because of mariadb and postgresql services not completed their jobs(no db) (depends_on only waits for containers to be ready)

Changes in code required by postgresql:

• Remove annotation Lob (type does not exist in Postgres)
• Set user table name in Table annotation. Table name in Postgresql must be lower case
• Change annotation Transactional readOnly value on class ClassificationServiceImpl.java from 'true' to 'false' (default value). Instead set readOnly = true on read methods. Postgresql is more strict than mariadb and overriding value on methods in class did not work.

ref: https://statistics-norway.atlassian.net/browse/DPMETA-856

ref: https://statistics-norway.atlassian.net/wiki/x/NgCmFQE