#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);
