… Percona Server 5.6.10 sandbox: description=MySQL driver=com.mysql.jdbc.Driver connectionSpec=jdbc:mysql://127.0.0.1:5610/schemaspy driverPath… more comprehensive example here. Running SchemaSpy The syntax below if specific for MySQL, but note that SchemaSpy works for pretty much all… additional tabs: Tables – Names, number of children, parents, count of columns, row counts, and comments — a great way for a high level…
Post: Replication in MySQL 5.6: GTIDs benefits and limitations - Part 2
May 30, 2013 By 6 Comments
… also lagging behind). s2> select count(*) from t; +———-+ | count(*) | +———-+ | 2 | +———-+ # s1 is behind s1> select count(*) from t; +———-+ | count(*) | +———-+ | 0 | +———-+ Can we still use…_port=10002; mysql> start slave; # And then check the number of records from the t table s1> select count(*) from t; +———-+ | count(*) | +———-+ | 2…. Scenario #3: The master has crashed before sending all writes If the binary logs of the master are no longer readable…
Comment: Derived Tables and Views Performance
May 21, 2013 By 16 Comments
…’,'root’,”); mysql_select_db(‘test’,$mysql); function display_menu($parent, $level) { $result = mysql_query(“SELECT a.id, a.label, a.link, Deriv1.Count FROM… ($row = mysql_fetch_assoc($result)) { if ($row['Count'] > 0) { echo “” . $row['label'] . “”; display_menu($row['id'], $level + 1); echo “”; } elseif ($row['Count']==0) { echo…
Post: MySQL Query Patterns, Optimized - Webinar questions followup
June 3, 2013 By 2 Comments
On Friday I gave a presentation on “MySQL Query Patterns, Optimized” for Percona MySQL Webinars. If you missed it, you can still register… queries. The query optimizer analyzes queries for common patterns the MySQL designers know can be improved. But there’s a finite… to count the movies per production year for each kind_id. It was more efficient in this case to force MySQL to…
Comment: Percona XtraBackup 2.1.3 for MySQL available for download
May 30, 2013 By 3 Comments
…_used_connections=13 max_threads=2002 thread_count=6 connection_count=6 It is possible that mysqld could … 4432877 K bytes of memory Hope that’s ok; if not, decrease some variables in the equation. Thread pointer… mysqld_safe mysqld from pid file /var/lib/mysql/srv-d2-mysql02.pid ended in an another …
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
… on standard MySQL replication from this instance, since MySQL replication is asynchronous. What about semi-sync MySQL replication? It’…flushing to the database periodically? if( $last_count % 100 == 0 ) { $db->do( “UPDATE achievements SET count = $last_count where achievement = ‘killed_troll’”; …
Post: Is your MySQL buffer pool warm? Make it sweat!
April 16, 2013 By 6 Comments
… for MySQL high availability. Many rely on MySQL’s asynchronous replication to maintain a warm standby server which is flipped into service if….1 –mysql-username playback –mysql-password PaSSwOrd –mysql-schema schema_name –query-log-stdin –dispatcher-plugin thread-pool –thread-pool-threads-count 100 –session… the same chunk again. We expected everything to be cached if we warmed the cache with the exact same data. All…
Post: Percona Playback 0.6 for MySQL now available
April 9, 2013 By 1 Comment
… it can read queries from MySQL query-log and MySQL tcpdump files and run them on other MySQL server. With Percona Playback you… be used for dispatching queries to MySQL database servers. This feature introduces new –thread-pool-threads-count option, which can be used… #1072845 (Stewart Smith). Percona Playback for MySQL wouldn’t reconnect or log the error if the connection was broken during the query…
Post: More on MySQL transaction descriptors optimization
April 26, 2013 By Leave a Comment
… results across all 3 boxes to see if different hardware has any notable impact: Still…=<1..1024> –test=oltp.lua –oltp_tables_count=8 –oltp-table-size=1000000 –rand-init… –percentile=99 –mysql-user=root –mysql-db=sbtest8t1M –mysql-table-engine=INNODB –mysql-socket=/tmp/mysql.sock –oltp-point…
Post: Finally. How to verify if all MySQL records were recovered
April 25, 2013 By Leave a Comment
…recovery case the same question arises: How many MySQL records were recovered and how many were lost….records the page stores. Obviously it doesn’t count any deleted records. The second method to …infinum and ends with another internal record supremum. If you follow record pointers from the infinum …
