Fernando, Yes, it was noticed, see for instance [1], but no solution was found.
Have you experimented with Connector/J properties or tried to change the pool implementation? Cheers, Milosz [1] http://n2.nabble.com/slow-performance-on-MySql-5.0-tp782401p782401.html > So I turned on logging of mysql queries (mysql connector/j), and it > looks like everytime a connection is gotten from the connection pool, it > executes a handful of queries against mysql. > > I was wondering if anyone has run into this, and if there is a way to > avoid all of the extra calls.. > > > > > > > 2008-12-17 13:16:02,244 [32336...@qtp0-0] INFO MySQL - Profiler Event: > [SLOW QUERY] at > org.apache.openjpa.jdbc.schema.SimpleDriverDataSource.getConnection(SimpleDriverDataSource.java:81) > > duration: 2 ms, > connection-id: 1980, statement-id: 99, resultset-id: 99, message: The > following query was executed with a bad index, use 'EXPLAIN' for more > details: /* mysql-connector-java-5.1.6 ( Revision: ${svn.Revision} > ) */SHOW VARIABLES WHERE Variable_name ='language' OR Variable_name = > 'net_write_timeout' OR Variable_name = 'interactive_timeout' OR > Variable_name = 'wait_timeout' OR Variable_name = 'character_set_client' > OR Variable_name = 'character_set_connection' OR Variable_name = > 'character_set' OR Variable_name = 'character_set_server' OR > Variable_name = 'tx_isolation' OR Variable_name = > 'transaction_isolation' OR Vari > able_name = 'character_set_results' OR Variable_name = 'timezone' OR > Variable_name = 'time_zone' OR Variable_name = 'system_time_zone' OR > Variable_name = 'lower_case_table_names' OR Variable_name = 'max_allo > wed_packet' OR Variable_name = 'net_buffer_length' OR Variable_name = > 'sql_mode' OR Variable_name = 'query_cache_type' OR Variable_name = > 'query_cache_size' OR Variable_name = 'init_connect' > 2008-12-17 13:16:02,246 [32336...@qtp0-0] INFO MySQL - Profiler Event: > [QUERY] at > org.apache.openjpa.jdbc.schema.SimpleDriverDataSource.getConnection(SimpleDriverDataSource.java:81) > > duration: 2 ms, > connection-id: 1980, statement-id: 99, resultset-id: 99, message: /* > mysql-connector-java-5.1.6 ( Revision: ${svn.Revision} ) */SHOW > VARIABLES WHERE Variable_name ='language' OR Variable_name = 'net_write_ti > meout' OR Variable_name = 'interactive_timeout' OR Variable_name = > 'wait_timeout' OR Variable_name = 'character_set_client' OR > Variable_name = 'character_set_connection' OR Variable_name = > 'character_set' OR > Variable_name = 'character_set_server' OR Variable_name = > 'tx_isolation' OR Variable_name = 'transaction_isolation' OR > Variable_name = 'character_set_results' OR Variable_name = 'timezone' OR > Variable_name > = 'time_zone' OR Variable_name = 'system_time_zone' OR Variable_name = > 'lower_case_table_names' OR Variable_name = 'max_allowed_packet' OR > Variable_name = 'net_buffer_length' OR Variable_name = 'sql_mode' OR > Variable_name = 'query_cache_type' OR Variable_name = > 'query_cache_size' OR Variable_name = 'init_connect' > 2008-12-17 13:16:02,250 [32336...@qtp0-0] INFO MySQL - Profiler Event: > [FETCH] at > org.apache.openjpa.jdbc.schema.SimpleDriverDataSource.getConnection(SimpleDriverDataSource.java:81) > > duration: 2 ms, > connection-id: 1980, statement-id: 99, resultset-id: 99 > 2008-12-17 13:16:02,253 [32336...@qtp0-0] INFO MySQL - Profiler Event: > [SLOW QUERY] at > org.apache.openjpa.jdbc.schema.SimpleDriverDataSource.getConnection(SimpleDriverDataSource.java:81) > > duration: 1 ms, > connection-id: 1980, statement-id: 100, resultset-id: 100, message: The > following query was executed with a bad index, use 'EXPLAIN' for more > details: SHOW COLLATION > 2008-12-17 13:16:02,254 [32336...@qtp0-0] INFO MySQL - Profiler Event: > [QUERY] at > org.apache.openjpa.jdbc.schema.SimpleDriverDataSource.getConnection(SimpleDriverDataSource.java:81) > > duration: 1 ms, > connection-id: 1980, statement-id: 100, resultset-id: 100, message: SHOW > COLLATION > 2008-12-17 13:16:02,255 [32336...@qtp0-0] INFO MySQL - Profiler Event: > [FETCH] at > org.apache.openjpa.jdbc.schema.SimpleDriverDataSource.getConnection(SimpleDriverDataSource.java:81) > > duration: 2 ms, > connection-id: 1980, statement-id: 100, resultset-id: 100 > 2008-12-17 13:16:02,257 [32336...@qtp0-0] INFO MySQL - Profiler Event: > [QUERY] at > org.apache.openjpa.jdbc.schema.SimpleDriverDataSource.getConnection(SimpleDriverDataSource.java:81) > > duration: 0 ms, > connection-id: 1980, statement-id: 999, resultset-id: 0, message: SET > NAMES latin1 > 2008-12-17 13:16:02,258 [32336...@qtp0-0] INFO MySQL - Profiler Event: > [FETCH] at > org.apache.openjpa.jdbc.schema.SimpleDriverDataSource.getConnection(SimpleDriverDataSource.java:81) > > duration: 0 ms, > connection-id: 1980, statement-id: 999, resultset-id: 0 > 2008-12-17 13:16:02,260 [32336...@qtp0-0] INFO MySQL - Profiler Event: > [QUERY] at > org.apache.openjpa.jdbc.schema.SimpleDriverDataSource.getConnection(SimpleDriverDataSource.java:81) > > duration: 1 ms, > connection-id: 1980, statement-id: 999, resultset-id: 0, message: SET > character_set_results = NULL > 2008-12-17 13:16:02,261 [32336...@qtp0-0] INFO MySQL - Profiler Event: > [FETCH] at > org.apache.openjpa.jdbc.schema.SimpleDriverDataSource.getConnection(SimpleDriverDataSource.java:81) > > duration: 0 ms, > connection-id: 1980, statement-id: 999, resultset-id: 0 > 2008-12-17 13:16:02,262 [32336...@qtp0-0] INFO MySQL - Profiler Event: > [QUERY] at > org.apache.openjpa.jdbc.schema.SimpleDriverDataSource.getConnection(SimpleDriverDataSource.java:81) > > duration: 0 ms, > connection-id: 1980, statement-id: 999, resultset-id: 0, message: SET > autocommit=1 > 2008-12-17 13:16:02,263 [32336...@qtp0-0] INFO MySQL - Profiler Event: > [FETCH] at > org.apache.openjpa.jdbc.schema.SimpleDriverDataSource.getConnection(SimpleDriverDataSource.java:81) > > duration: 0 ms, > connection-id: 1980, statement-id: 999, resultset-id: 0 > 2008-12-17 13:16:02,265 [32336...@qtp0-0] INFO MySQL - Profiler Event: > [QUERY] at > org.apache.openjpa.jdbc.schema.SimpleDriverDataSource.getConnection(SimpleDriverDataSource.java:81) > > duration: 1 ms, > connection-id: 1980, statement-id: 999, resultset-id: 0, message: SET > sql_mode='STRICT_TRANS_TABLES' > 2008-12-17 13:16:02,266 [32336...@qtp0-0] INFO MySQL - Profiler Event: > [FETCH] at > org.apache.openjpa.jdbc.schema.SimpleDriverDataSource.getConnection(SimpleDriverDataSource.java:81) > > duration: 0 ms, > connection-id: 1980, statement-id: 999, resultset-id: 0 > 2008-12-17 13:16:02,267 [32336...@qtp0-0] INFO MySQL - Profiler Event: > [QUERY] at > org.apache.openjpa.lib.jdbc.DelegatingConnection.setAutoCommit(DelegatingConnection.java:198) > > duration: 0 ms, connec > tion-id: 1980, statement-id: 999, resultset-id: 0, message: SET autocommit=0 > 2008-12-17 13:16:02,268 [32336...@qtp0-0] INFO MySQL - Profiler Event: > [FETCH] at > org.apache.openjpa.lib.jdbc.DelegatingConnection.setAutoCommit(DelegatingConnection.java:198) > > duration: 0 ms, connection-id: 1980, statement-id: 999, resultset-id: 0 >
