MySQL Bugs: #40561: rewriteBatchedStatements no longer works with replace statements

Bug #40561	rewriteBatchedStatements no longer works with replace statements
Submitted:	6 Nov 2008 20:00	Modified:	20 Jul 2015 17:29
Reporter:	Ryan Albarelli	Email Updates:
Status:	Duplicate	Impact on me:	None
Category:	Connector / J	Severity:	S3 (Non-critical)
Version:	5.1.7	OS:	Any
Assigned to:	Filipe Silva	CPU Architecture:	Any
Tags:	rewriteBatchedStatements replace batch

Description:
It appears the ability to rewrite batched REPLACE statements was inadvertently dropped on the check-in listed below. The log comment seems to imply that REPLACE statements are still supported, but the code change removes it.

http://lists.mysql.com/commits/29897?f=plain

Thanks.

How to repeat:
PreparedStatement stmt = conn.prepareStatement( "REPLACE INTO test( test_id, test_val ) VALUES ( ?, ? )", Statement.RETURN_GENERATED_KEYS );

// Add a new value with auto-generated key
stmt.setNull( 1, java.sql.Types.INTEGER );
stmt.setInt( 2, 71 );
stmt.addBatch();
            
Replace an old value with key=1
stmt.setInt( 1, 1 );
stmt.setInt( 2, 72 );
stmt.addBatch();

stmt.executeBatch();

The statements are not rewritten even though the syntax is the same for INSERT and REPLACE. Two statements are executed instead of one.

Suggested fix:
Revert the logic condition to support REPLACE statements, or indicate that the support was intentionally dropped.

The function in question is canRewriteAsMultivalueInsertStatement() in PreparedStatement.java

Hi Ryan and thanks for your report.

Verified as described by looking into latest sources. I am sure Mark had good reason for doing this (maybe Bug#39352) so I'll wait for his explanation leaving report without triage until then.

Duplicate of Bug#77681. Please follow progress in Bug#77681 report.