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  • Committer: vjsamuel1990 at gmail
  • Date: 2011-02-04 18:26:39 UTC
  • mto: This revision was merged to the branch mainline in revision 2147.
  • Revision ID: vjsamuel1990@gmail.com-20110204182639-e8tbwkbdzdw86it6
Merge encapsulate join_read_const_table() into JoinTable.

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drizzled/join_table.cc
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#include "config.h"
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#include <drizzled/join_table.h>
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#include <drizzled/field/blob.h>
 
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#include <drizzled/sql_select.h>
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namespace drizzled
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{
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int JoinTable::join_read_const_table(optimizer::Position *pos)
 
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{
 
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  int error;
 
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  Table *Table= this->table;
 
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  Table->const_table=1;
 
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  Table->null_row=0;
 
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  Table->status=STATUS_NO_RECORD;
 
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  if (this->type == AM_SYSTEM)
 
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  {
 
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    if ((error=join_read_system(this)))
 
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    {                                           // Info for DESCRIBE
 
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      this->info="const row not found";
 
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      /* Mark for EXPLAIN that the row was not found */
 
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      pos->setFanout(0.0);
 
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      pos->clearRefDependMap();
 
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      if (! Table->maybe_null || error > 0)
 
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        return(error);
 
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    }
 
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  }
 
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  else
 
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  {
 
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    if (! Table->key_read && 
 
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        Table->covering_keys.test(this->ref.key) && 
 
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        ! Table->no_keyread &&
 
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        (int) Table->reginfo.lock_type <= (int) TL_READ_WITH_SHARED_LOCKS)
 
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    {
 
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      Table->key_read=1;
 
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      Table->cursor->extra(HA_EXTRA_KEYREAD);
 
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      this->index= this->ref.key;
 
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    }
 
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    error=join_read_const(this);
 
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    if (Table->key_read)
 
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    {
 
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      Table->key_read=0;
 
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      Table->cursor->extra(HA_EXTRA_NO_KEYREAD);
 
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    }
 
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    if (error)
 
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    {
 
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      this->info="unique row not found";
 
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      /* Mark for EXPLAIN that the row was not found */
 
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      pos->setFanout(0.0);
 
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      pos->clearRefDependMap();
 
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      if (!Table->maybe_null || error > 0)
 
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        return(error);
 
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    }
 
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  }
 
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  if (*this->on_expr_ref && !Table->null_row)
 
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  {
 
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    if ((Table->null_row= test((*this->on_expr_ref)->val_int() == 0)))
 
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      Table->mark_as_null_row();
 
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  }
 
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  if (!Table->null_row)
 
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    Table->maybe_null=0;
 
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  /* Check appearance of new constant items in Item_equal objects */
 
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  Join *Join= this->join;
 
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  if (Join->conds)
 
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    update_const_equal_items(Join->conds, this);
 
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  TableList *tbl;
 
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  for (tbl= Join->select_lex->leaf_tables; tbl; tbl= tbl->next_leaf)
 
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  {
 
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    TableList *embedded;
 
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    TableList *embedding= tbl;
 
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    do
 
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    {
 
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      embedded= embedding;
 
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      if (embedded->on_expr)
 
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         update_const_equal_items(embedded->on_expr, this);
 
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      embedding= embedded->getEmbedding();
 
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    }
 
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    while (embedding &&
 
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           embedding->getNestedJoin()->join_list.head() == embedded);
 
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  }
 
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  return(0);
 
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}
 
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void JoinTable::readCachedRecord()
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{
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  unsigned char *pos;