Class PgStatistics

All Implemented Interfaces:
ISearchPath, IStatement, IStatistics, IHashable

public class PgStatistics extends PgAbstractStatement implements IStatistics, ISearchPath
PostgreSQL extended statistics implementation. Extended statistics collect additional information about column correlations and distributions to improve query planning for multi-column predicates.
  • Constructor Details

    • PgStatistics

      public PgStatistics(String name)
      Creates a new PostgreSQL statistics object.
      Parameters:
      name - statistics object name
  • Method Details

    • getCreationSQL

      public void getCreationSQL(SQLScript script)
      Description copied from interface: IStatement
      Generates the SQL statements needed to create this database object. This is an abstract method that must be implemented by subclasses to provide the specific CREATE SQL for each object type.
      Specified by:
      getCreationSQL in interface IStatement
      Parameters:
      script - the SQL script to append creation statements to
    • appendAlterSQL

      public ObjectState appendAlterSQL(IStatement newCondition, SQLScript script)
      Description copied from interface: IStatement
      Fill script with object changes and return change type
      Specified by:
      appendAlterSQL in interface IStatement
      Parameters:
      newCondition - new object state
      script - script to collect changes
      Returns:
      object change type
    • setForeignSchema

      public void setForeignSchema(String foreignSchema)
    • setForeignTable

      public void setForeignTable(String foreignTable)
    • setStatistics

      public void setStatistics(int statistics)
    • addKind

      public void addKind(String kind)
      Adds a statistics kind (ndistinct, dependencies, mcv, etc.).
      Parameters:
      kind - statistics type to collect
    • addExpr

      public void addExpr(String expression)
      Adds a column expression for statistics collection.
      Parameters:
      expression - column name or expression
    • getForeignSchema

      public String getForeignSchema()
    • getForeignTable

      public String getForeignTable()
    • computeHash

      public void computeHash(Hasher hasher)
      Description copied from interface: IHashable
      Computes the hash of the implementing object using the provided hasher. The implementation should call appropriate put methods on the hasher for all fields that should contribute to the hash value.
      Specified by:
      computeHash in interface IHashable
      Parameters:
      hasher - the hasher instance to use for hash computation
    • compare

      public boolean compare(IStatement obj)
      Description copied from class: AbstractStatement
      This method does not account for nested child PgStatements. Shallow version of AbstractStatement.equals(Object)
      Specified by:
      compare in interface IStatement
      Overrides:
      compare in class AbstractStatement