Package com.atlassian.confluence.internal.upgrade.constraint.dedup

Class Deduper

java.lang.Object
com.atlassian.confluence.internal.upgrade.constraint.dedup.Deduper
public class Deduper extends Object
Remove duplicated rows from a table before a unique constraint can be added. This is a 2-step process: 1. Query all duplicate rows 2. Use a suitable DedupeStrategy to delete those duplicates Note: 1. Tables with composite keys are not supported. 2. This implementation doesn't scale well because it puts everything in memory and process DMLs one at a time
Since:
7.1.0

  • Constructor Summary

    Constructors
    Constructor
    Description
    Deduper(org.hibernate.SessionFactory sessionFactory, com.atlassian.config.db.HibernateConfig hibernateConfig)
     

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    multipleNullsNotAllowed()
    Oracle and SQL Server behave differently from the rest: two rows that contain nulls for one or more key columns and the same combination of values for the other key columns violate a unique constraint.
    long
    removeDuplicates(String table, String idColumn, List<String> uniqueColumns, DedupeStrategy dedupeStrategy)
    Remove all duplicates of combination of uniqueColumns from table.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Deduper

      public Deduper(org.hibernate.SessionFactory sessionFactory, com.atlassian.config.db.HibernateConfig hibernateConfig)

  • Method Details

    • removeDuplicates

      public long removeDuplicates(String table, String idColumn, List<String> uniqueColumns, DedupeStrategy dedupeStrategy) throws UpgradeException
      Remove all duplicates of combination of uniqueColumns from table. Note: names of tables and columns are not to be quoted.
      Returns:
      number of duplicate rows removed
      Throws:
      UpgradeException

    • multipleNullsNotAllowed

      public boolean multipleNullsNotAllowed()
      Oracle and SQL Server behave differently from the rest: two rows that contain nulls for one or more key columns and the same combination of values for the other key columns violate a unique constraint.
      Returns:
      true if current SQL vendor doesn't accepts multiple null values in multi-column unique constraints