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  • Committer: Prafulla Tekawade
  • Date: 2010-07-13 16:07:35 UTC
  • mto: (1662.1.4 rollup)
  • mto: This revision was merged to the branch mainline in revision 1664.
  • Revision ID: prafulla_t@users.sourceforge.net-20100713160735-2fsdtrm3azayuyu1
This bug is simillar to mysql bug 36133
http://bugs.mysql.com/bug.php?id=36133

Taking changes from that fix.

  - The problem was that the range optimizer evaluated constant expressions, 
    and among them it would try to evaluate IN-subquery predicates slated for
    handling with materialization strategy. However, these predicates require
    that parent_join->setup_subquery_materialization() is invoked before one
    attempts to evaluate them.
  
  - Fixed by making the range optimizer not to evaluate expressions that have
    item->is_expensive() == TRUE (these are materialization subqueries and 
    stored function calls). This should also resolve the problem that EXPLAIN 
    may be too long. 
    This change cuts off some opportunities for range optimizer, but this is 
    the price we're willing to pay for separation of query optimization and
    execution. 

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drizzled/tmp_table_param.h
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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
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 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
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 *
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 *  Copyright (C) 2008 Sun Microsystems, Inc.
 
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 *  Copyright (C) 2008 Sun Microsystems
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 *
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 *  This program is free software; you can redistribute it and/or modify
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 *  it under the terms of the GNU General Public License as published by
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#ifndef DRIZZLED_TMP_TABLE_PARAM_H
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#define DRIZZLED_TMP_TABLE_PARAM_H
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#include <plugin/myisam/myisam.h>
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namespace drizzled
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{
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class CopyField;
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/*
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  Param to create temporary tables when doing SELECT:s
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  NOTE
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  const CHARSET_INFO *table_charset;
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  Tmp_Table_Param() :
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    keyinfo(0),
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    copy_funcs(),
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    save_copy_funcs(),
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    copy_field(0),
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    copy_field_end(0),
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    save_copy_field(0),
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    save_copy_field_end(0),
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    group_buff(0),
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    items_to_copy(0),
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    recinfo(0),
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    start_recinfo(0),
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    end_write_records(0),
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    field_count(0),
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    sum_func_count(0),
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    func_count(0),
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    hidden_field_count(0),
 
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  Tmp_Table_Param()
 
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    :copy_field(0),
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    group_parts(0),
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    group_length(0),
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    group_null_parts(0),
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    quick_group(0),
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    using_indirect_summary_function(false),
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    schema_table(false),
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    precomputed_group_by(false),
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    force_copy_fields(false),
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    convert_blob_length(0),
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    table_charset(0)
 
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    convert_blob_length(0)
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  {}
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  ~Tmp_Table_Param()
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  {
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    cleanup();