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https://dev.mysql.com/doc/internals/en/myisam-directory.html
They are: mi_cache.c --- for reading records from a cache mi_changed.c --- a single routine for setting a "changed" flag (very short) mi_check.c --- for checking and repairing tables. Can be used to exactly replay a set of changes to a table.
https://dev.mysql.com/doc/internals/en/myisampack.html
When starting to analyze the existing uncompressed data, it collects distinct column values up to a limit of 8KB. If there are more, it falls back to byte value compression for this column. This means also that myisampack may use different ...
https://dev.mysql.com/doc/internals/en/opening-a-table.html
Before any read or write operations are performed on a table, the MySQL server will call the [custom-engine.html#custom-engine-api-reference-open handler::open()] method to open the table data and index files (if they exist). int open(const char ...
https://dev.mysql.com/doc/internals/en/optimizer-transpositions.html
In other words: WHERE - 5 = column1 becomes: WHERE column1 = -5 However, MySQL does not support transpositions where arithmetic exists. MySQL supports transpositions (reversing the order of operands around a relational operator) for simple ...
https://dev.mysql.com/doc/internals/en/prepared-stored-procedure-execution.html
Execution of a stored procedure statement is similar to execution of a prepared statement. During execution of a stored procedure, THD::stmt_arena points to the permanent query arena of the stored procedure. This arena happens to be also the ...
https://dev.mysql.com/doc/internals/en/prepared-stored-statement-execution.html
No other mechanism exists in the server at the moment to allow re-execution. In order to call mysql_execute_command (the function that executes a statement) for a prepared statement and not damage its parse tree, we backup and restore the active ...
https://dev.mysql.com/doc/internals/en/records-in-range.html
Given a starting key, and an ending key estimate the number of rows that will exist between the two. Purpose For the given range how many records are estimated to be in this range. Synopsis virtual ha_rows records_in_range ( inx, min_key, max_key); ...
https://dev.mysql.com/doc/internals/en/select-select-result.html
This class has a very important role in SELECT performance with select_result class and classes inherited from it (usually called with a select_ prefix). The key methods in this class are the following: send_fields sends given item list headers ...
https://dev.mysql.com/doc/internals/en/select-structure.html
There are two structures that describe selects: st_select_lex (SELECT_LEX) for representing SELECT itself st_select_lex_unit (SELECT_LEX_UNIT) for grouping several selects in a bunch The latter item represents UNION operation (the absence of UNION ...
https://dev.mysql.com/doc/internals/en/threads.html
Calls thr_setconcurrency() if it is available at compile time; this call is generally assumed to exist only on Solaris, its value should reflect the number of physical CPUs. Threads in mysqld can run at four different priorities, defined in ...