Percona's MySQL & InnoDB performance and scalability blog
… GTID-based replication. That will show where GTIDs shine and where improvements are expected. This is …also lagging behind). s2> select count(*) from t; +———-+ | count(*) | +———-+ | 2 | +———-+ # s1 is behind s1> select count(*) from t; +———-+ | count(*) | +———-+ | 0 | …
… want to merge on the fly (e.g. SELECT cols FROM idx1p0,idx1p1,idx1p2 WHERE …), otherwise if it’s more convenient that the…
… <<'EOF' > discard-ddl.sql SELECT CONCAT(‘ALTER TABLE `’, table_name, ‘` DISCARD TABLESPACE;’) AS _ddl FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA=’orig’ AND… <<'EOF' > import-ddl.sql SELECT CONCAT(‘ALTER TABLE `’, table_name, ‘` IMPORT TABLESPACE;’) AS _ddl FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA=’orig’ AND…
… developer to refactor manually. There could also be some cases where optimizing a query automatically would be more costly than just… form. Q: Doesn’t the primary key solution for random selection only work when the IDs for movies are distributed uniformly… different order from what you specify in the query? The tuple comparison you’re referring to is this example: WHERE (k1.keyword…
…’,”); mysql_select_db(‘test’,$mysql); function display_menu($parent, $level) { $result = mysql_query(“SELECT a.id, a.label, a.link, Deriv1.Count FROM `menu` a LEFT OUTER JOIN (SELECT parent, COUNT(*) AS Count FROM `menu` GROUP BY parent) Deriv1 ON a.id = Deriv1.parent WHERE…
… the same in 5.5. Here is the related output from show engine innodb status: —TRANSACTION BB0E42A, ACTIVE 3 sec fetching… table create table t as SELECT ld.label_id, cai.inventory_id, COUNT(1) as installed_count from client_app_inventory cai… label_to_device ld on (ld.device_id = d.id) where ld.trash = ‘f’ and cai.trash = ‘f’ and (cai.status…
Selecting the most appropriate solution for a MySQL HA infrastructure is… in which we’ll explore the topic of MySQL HA from each of these perspectives. The goal will be to …system stack) and then conclude with some typical use cases where a given approach may be well-suited or particularly …
… table id to find indexes of the table. mysql> select * from SYS_TABLES WHERE NAME=’sakila/actor’; +————–+—–+——–+——+——–+———+————–+——-+ | NAME | ID | N_COLS | TYPE | MIX… minimal `ID` among the indexes of the table. mysql> select * from SYS_INDEXES WHERE TABLE_ID=741; +———-+——+———————+———-+——+——-+———+ | TABLE_ID | ID | NAME | N_FIELDS…
… updates to the database, all SELECT queries, even those participating in read-only transactions, start suffering from the trx_list overhead created… queries: select avg(id) from sbtest$i force key (primary) select count(*) from sbtest$i WHERE k like ‘%0%’ SysBench-0.5/lua: POINT_SELECT QPS…
…. [caption id="" align="alignright" width="336"] Registration signs from the 2003 MySQL Users Conference and Expo in … many of the other shows I speak at where all I get is an awkward silence which … and services, then you’ll see the largest selection of MySQL Ecosystem vendors at the show. If …
Copyright © Percona LLC • Contact Us • MySQL and InnoDB are trademarks of Oracle Corp.