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https://dev.mysql.com/doc/internals/en/example-one-mysql-packet.html
A COM_QUERY for select "012345678901234567890123456789012345" without CLIENT_COMPRESS has a payload length of 46 bytes looks like: 2e 00 00 00 03 73 65 6c 65 63 74 20 22 30 31 32 .....select "012 33 34 35 36 37 38 39 30 31 32 33 34 35 36 37 38 ...
https://dev.mysql.com/doc/internals/en/guided-tour-majordir-sql.html
If you remember your manual, you know that you must pronounce this: ess queue ell. The "parser" programs on mysql-5.0/sql: size name comment ---- ---- ------- 51326 sql_lex.cc lexer 230026 sql_yacc.yy parser + many more *.cc programs This is where ...
https://dev.mysql.com/doc/internals/en/guided-tour-skeleton.html
Walking Through The Server Code: /sql/sql_parse.cc void mysql_execute_command(THD *thd) switch (lex->sql_command) { case SQLCOM_SELECT: ... Remember, by the way, that MySQL stores frequently-used select statements and result sets in memory as an ...
https://dev.mysql.com/doc/internals/en/item-class.html
MySQL's Item class is defined in .../sql/item.h, and its subclasses are defined in .../sql/item*.h (that is, in item.h, item_cmpfunc.h, item_func.h, item_geofunc.h, item_row.h, item_strfunc.h, item_subselect.h, item_sum.h, item_timefunc.h). To us, ...
https://dev.mysql.com/doc/internals/en/optimizer-constants-constant-tables.html
Here's an example: SELECT Table1.unique_not_null_column, Table2.any_column FROM Table1, Table2 WHERE Table1.unique_not_null_column = Table2.any_column AND Table1.unique_not_null_column = 5; When evaluating this query, MySQL first finds that table ...
https://dev.mysql.com/doc/internals/en/optimizer-definitions.html
To make that easy, this description includes notes referring to the relevant file and routine, such as “See: /sql/select_cc, optimize_cond()”. WHERE 5 = a to SELECT ...WHERE a = 5 Most transformations are less obvious. This description uses a ...
https://dev.mysql.com/doc/internals/en/optimizer-tracing-typical-usage.html
# Turn tracing on (it's off by default): SET optimizer_trace="enabled=on"; SELECT ...; # your query here SELECT * FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE; # possibly more queries... # When done with tracing, disable it: SET ...
https://dev.mysql.com/doc/internals/en/prepared-stored.html
for a SELECT statement, this set includes a list of Item's for SELECT list, a list of tables (TABLE_LIST object for each table) for FROM clause, and a tree of Item's for WHERE clause. Let us start with a general description of the MySQL statement ...
https://dev.mysql.com/doc/internals/en/row-order-within-result-sets.html
Either use --sorted_result SELECT * FROM t1; or, if possible, "decorate" your SELECT with ORDER BY to make the row order static. Please keep in mind that the row order within a significant number of result sets depends on storage engine properties ...
https://dev.mysql.com/doc/internals/en/sql-directory.html
Programs for handling SQL commands. The "core" of MySQL. These are the .c and .cc files in the sql directory: derror.cc --- read language-dependent message file des_key_file.cc --- load DES keys from plaintext file discover.cc --- Functions for ...