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merge with 5.1

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This commit is contained in:
Sergei Golubchik
2010-10-25 15:21:16 +02:00
parent 37a78d6868 60c15066db
commit 04a4b43346
230 changed files with 4615 additions and 1320 deletions
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42
sql/handler.cc
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@ -2049,6 +2049,21 @@ handler *handler::clone(MEM_ROOT *mem_root)
return new_handler;
}
double handler::keyread_time(uint index, uint ranges, ha_rows rows)
{
/*
It is assumed that we will read trough the whole key range and that all
key blocks are half full (normally things are much better). It is also
assumed that each time we read the next key from the index, the handler
performs a random seek, thus the cost is proportional to the number of
blocks read. This model does not take into account clustered indexes -
engines that support that (e.g. InnoDB) may want to overwrite this method.
*/
double keys_per_block= (stats.block_size/2.0/
(table->key_info[index].key_length +
ref_length) + 1);
return (rows + keys_per_block - 1)/ keys_per_block;
}
void **handler::ha_data(THD *thd) const
{
@ -3122,33 +3137,6 @@ int handler::ha_check(THD *thd, HA_CHECK_OPT *check_opt)
return update_frm_version(table);
}
/*
Calculate cost of 'index only' scan for given index and number of records.
SYNOPSIS
handler->keyread_read_time()
index key to read
ranges number of ranges
rows #of records to read
NOTES
It is assumed that we will read trough all key ranges and that all
key blocks are half full (normally things are much better). It is also
assumed that each time we read the next key from the index, the handler
performs a random seek, thus the cost is proportional to the number of
blocks read.
*/
double handler::keyread_read_time(uint index, uint ranges, ha_rows rows)
{
double read_time;
uint keys_per_block= (stats.block_size/2/
(table->key_info[index].key_length + ref_length) + 1);
read_time=((double) (rows+keys_per_block-1)/ (double) keys_per_block);
return read_time;
}
/**
A helper function to mark a transaction read-write,
if it is started.