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https://dev.mysql.com/doc/internals/en/negative-tests.html
String longer than column Limited number of tables, columns, variables, ... Maximum - 1, Maximum, Maximum + 1 Assume an SQL operation that affects the filesystem (LOAD DATA, CREATE SCHEMA or TABLE, backup/restore, ...). A "negative" test is a test ...
https://dev.mysql.com/doc/internals/en/optimizer-code.html
*/ optimize_cond() opt_sum_query() make_join_statistics() get_quick_record_count() choose_plan() /* Find the best way to access tables */ /* as specified by the user. The make_join_statistics() routine puts together all the information it can find ... This diagram shows the structure of the function handle_select() in /sql/sql_select.cc (the server code that handles a query): handle_select() mysql_select() JOIN::prepare() setup_fields() JOIN::optimize() /* optimizer is from here ...
https://dev.mysql.com/doc/internals/en/optimizer-eliminating-dead-code.html
SELECT * FROM Table1 WHERE column1 = 'Canada'; The optimizer will not eliminate the condition in the query, even though the CREATE TABLE definition makes it an impossible condition. A transformation takes place for conditions that are always true, ...
https://dev.mysql.com/doc/internals/en/select-special-engines.html
The normal engine can be replaced with such special engines only during the optimization process.
https://dev.mysql.com/doc/internals/en/sleep.html
Example: --connection conn1 LOCK TABLE t1 WRITE; --connection conn2 # This will block in wait_for_lock(). FLUSH TABLE t1; The BIG, BIG problem with 'sleep' is that you need to specify a fixed time. In some cases race conditions can be repeated when ...
https://dev.mysql.com/doc/internals/en/threads.html
Like the old "sync" daemon in unix, this thread occasionally flushes MyISAM tables to disk. Threads in mysqld can run at four different priorities, defined in mysql_priv.h: #define INTERRUPT_PRIOR 10 #define CONNECT_PRIOR 9 #define WAIT_PRIOR 8 ...
https://dev.mysql.com/doc/internals/en/user-level-locks.html
LOCK TABLE t1 IN SHARE MODE; --connection conn2 # Acquire the user level lock "mysqltest1". User-level locks are controlled with the SQL functions GET_LOCK(str,timeout) IS_FREE_LOCK(str) IS_USED_LOCK(str) RELEASE_LOCK(str) They can be used at ...
https://dev.mysql.com/doc/internals/en/wait-condition.html
Example: --connection conn1 LOCK TABLE t1 WRITE; --connection conn2 # Get the id of this thread. FLUSH TABLE t1; In conn2 we get the thread ID first. Like 'sleep', this method can also be used, when all but one thread reach a blocked state. If you ...
https://dev.mysql.com/doc/mysql-installer/en/mysql-installer-setup.html
The following table describes the files and folders that define MySQL Installer as a standalone application. Table 2.1 MySQL Installer Configuration Files File or Folder Description Folder Hierarchy MySQL Installer for Windows This folder contains ... Choosing a Setup Type Path Conflicts Check Requirements MySQL Installer Configuration Files When you download MySQL Installer for the first time, a setup wizard guides you through the initial installation of MySQL ...
https://dev.mysql.com/doc/ndbapi/en/mccj-clusterj-annotation-partitionkey.html
Annotation on a class or member to define the partition key. If annotating a class or interface, either a single column or multiple columns can be specified. If annotating a member, neither column nor columns should be specified.