Package edu.caltech.nanodb.queryeval

Interface Planner

  • All Known Implementing Classes:
    CostBasedJoinPlanner, SimplestPlanner
    public interface Planner

    This interface specifies the common entry-point for all query planner/optimizer implementations. The interface is very simple, but a particular implementation might be very complicated depending on what kinds of optimizations are implemented. Note that a new planner/optimizer is created for each query being planned.

    To support initialization of arbitrary planners, a Planner implementation should only have a default constructor.

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      PlanNode makePlan​(SelectClause selClause, java.util.List<SelectClause> enclosingSelects)
      Returns the root of a plan tree suitable for executing the specified query.
      SelectNode makeSimpleSelect​(java.lang.String tableName, Expression predicate, java.util.List<SelectClause> enclosingSelects)
      Returns a plan tree for executing a simple select against a single table, whose tuples can also be used for updating and deletion.
      void setStorageManager​(StorageManager storageManager)
      Allows the storage manager to be injected into the planner implementation, so that the planner can retrieve schema and statistics on tables that are referenced by the query.

    • Method Detail

      • setStorageManager

        void setStorageManager​(StorageManager storageManager)
        Allows the storage manager to be injected into the planner implementation, so that the planner can retrieve schema and statistics on tables that are referenced by the query.
        Parameters:
        storageManager - the storage manager instance for the planner implementation to use

      • makePlan

        PlanNode makePlan​(SelectClause selClause,
                  java.util.List<SelectClause> enclosingSelects)
        Returns the root of a plan tree suitable for executing the specified query. There is no requirement that tuples produced by the returned plan should support updating or deletion.
        Parameters:
        selClause - an object describing the query to be performed
        enclosingSelects - a list of enclosing queries, if selClause is a nested subquery. This is allowed to be an empty list, or null, if the query is a top-level query. If selClause is a nested subquery, enclosingSelects[0] is the outermost enclosing query, then enclosingSelects[1] is enclosed by enclosingSelects[0], and so forth. The most tightly enclosing query is the last one in enclosingSelects.
        Returns:
        a plan tree for executing the specified query

      • makeSimpleSelect

        SelectNode makeSimpleSelect​(java.lang.String tableName,
                            Expression predicate,
                            java.util.List<SelectClause> enclosingSelects)
        Returns a plan tree for executing a simple select against a single table, whose tuples can also be used for updating and deletion. This is a strict requirement, as this method is used by the UpdateCommand and DeleteCommand classes to create the plans suitable for performing tuple modification or deletion.
        Parameters:
        tableName - the table that the select will operate against
        predicate - the selection predicate to apply, or null if all tuples in the table should be returned
        enclosingSelects - a list of enclosing queries, if selClause is a nested subquery. This is allowed to be an empty list, or null, if the query is a top-level query. If selClause is a nested subquery, enclosingSelects[0] is the outermost enclosing query, then enclosingSelects[1] is enclosed by enclosingSelects[0], and so forth. The most tightly enclosing query is the last one in enclosingSelects.
        Returns:
        a plan tree for executing the select operation