… An additional benefit is that SchemaSpy is command-line…MySQL driver=com.mysql.jdbc.Driver connectionSpec=jdbc:mysql://127.0.0.1:5610/schemaspy driverPath=/usr/share/java/mysql-connector-java.jar Example Schema…any host:port or schema name information. Viewing SchemaSpy… you’re done. What are some ERD…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
…helps encapsulate a lot of this information and puts it into context with …standard MySQL replication from this instance, since MySQL replication is asynchronous. What about semi-sync MySQL replication?…_count where achievement = ‘killed_troll’”; } change your schema In Example 2, above, how above …
Post: Is your MySQL buffer pool warm? Make it sweat!
April 16, 2013 By 6 Comments
…What does that mean? In most of these high-availability solutions it means that mysqld is…(See my Fosdem 2013 slides for information about discarded designs and benchmarks.) First…-playback –mysql-host 127.0.0.1 –mysql-username playback –mysql-password PaSSwOrd –mysql-schema schema_name –query…
Post: INFORMATION_SCHEMA tables in the InnoDB pluggable storage engine
May 24, 2008 By Leave a Comment
…is INFORMATION_SCHEMA tables that show some status information about InnoDB. Here are the tables: mysql> SHOW TABLES FROM INFORMATION_SCHEMA LIKE ‘INNODB%’; +—————————————-+ | Tables_in_INFORMATION_SCHEMA…what is blocking what and so on. Note that the InnoDB plugin manual is…
Post: Should we give a MySQL Query Cache a second chance ?
April 10, 2011 By 64 Comments
… Manageability What is in the MySQL Query Cache ? How many hits did we get for this query item ? Right now none of such information is… Cache content and operation can be presented as some INFORMATION_SCHEMA tables. Self Refresh MySQL Query Cache causes not uniform performance as you…
Post: Eventual Consistency in MySQL
November 18, 2011 By 8 Comments
…mysql -N | mysql -E *************************** 1. row *************************** test.Bar.ID: 42 DIY RI We can get information about foreign key constraints from the INFORMATION_SCHEMA, but what…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 5 Comments
… of how memory is allocated from OS you might not see “VSZ” going down. What you might see instead is flushing tables regularly… at information_schema to see how much memory is being used by current MEMORY tables: mysql> select sum(data_length+index_length) from information_schema.tables…
Post: How to debug long-running transactions in MySQL
March 8, 2011 By 6 Comments
…’s actually easy to figure out what the long-running transaction is doing. The most obvious is if it’s a long-running… exit 1 fi host=$(mysql -ss -e ‘SELECT p.HOST FROM information_schema.innodb_lock_waits w INNER JOIN information_schema.innodb_trx b ON… INNER JOIN information_schema.processlist p on b.trx_mysql_thread_id = p.ID LIMIT 1′) if [ "${host}" ]; then echo “Host ${host} is blocking…
Post: MySQL Wish for 2013 - Better Memory Accounting
December 31, 2012 By 6 Comments
With Performance Schema improvements in MySQL 5.6 I think we’re in the good shape with insight on what is causing performance bottlenecks… ensure the memory consumption by various database operations is reasonable. For example if some INFORMATION_SCHEMA query were to take couple of GB…
Post: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
… system. innodb_stats_on_metadata is disabled by default in MySQL 5.6 Welcome to much faster information_schema queries! innodb_log_file_size – default has been increased from 5MB to approximately 50MB which is a good… to 12M. I’m not sure what is the purpose of this change but it is unlikely to have any practical meaning for…
