Re: bzr commit into mysql-5.1 branch (hezx:2666) Bug#35843

[Mats Kindahl]

Hi Jason!

The patch looks good, but I would suggest to add a call to start_bulk_delete()
and start_bulk_update() at the appropriate places. They don't take an argument,
so there is nothing to compute for that.

Just my few cents,
Mats Kindahl

He Zhenxing wrote:
> #At file:///media/sda3/work/mysql/bzrwork/b35843/5.1-rpl/
> 
>  2666 He Zhenxing	2008-09-10
>       BUG#35843 Slow replication slave when using partitioned myisam table
>       
>       In order to improve the performance when replicating to partitioned
>       myisam tables with row-based format, the number of rows of current 
>       rows log event is estimated and used to setup storage engine for bulk
>       inserts.
> modified:
>   sql/log_event.cc
> 
> === modified file 'sql/log_event.cc'
> --- a/sql/log_event.cc	2008-08-06 10:41:27 +0000
> +++ b/sql/log_event.cc	2008-09-10 09:13:58 +0000
> @@ -7488,7 +7488,6 @@ Write_rows_log_event::do_before_row_oper
>      */
>    }
>  
> -  m_table->file->ha_start_bulk_insert(0);
>    /*
>      We need TIMESTAMP_NO_AUTO_SET otherwise ha_write_row() will not use fill
>      any TIMESTAMP column with data from the row but instead will use
> @@ -7627,7 +7626,16 @@ Rows_log_event::write_row(const Relay_lo
>    
>    /* unpack row into table->record[0] */
>    error= unpack_current_row(rli); // TODO: how to handle errors?
> -
> +  if (m_curr_row == m_rows_buf)
> +  {
> +    /* this is the first row to be inserted, we estimate the rows with
> +       the size of the first row and use that value to initialize
> +       storage engine for bulk insertion */
> +    ulong estimated_rows= (m_rows_end - m_curr_row) / (m_curr_row_end -
> m_curr_row);
> +    m_table->file->ha_start_bulk_insert(estimated_rows);
> +  }
> +  
> +  
>  #ifndef DBUG_OFF
>    DBUG_DUMP("record[0]", table->record[0], table->s->reclength);
>    DBUG_PRINT_BITSET("debug", "write_set = %s", table->write_set);
> 
> 


-- 
Mats Kindahl
Lead Software Developer
Replication Team
MySQL AB, www.mysql.com