query graph
/* Query graph query thread node: the fields are protected by the kernel mutex with the exceptions named below */
struct que_thr_struct{ que_common_t common; /*!< type: QUE_NODE_THR */ ulint magic_n; /*!< magic number to catch memory corruption */ que_node_t* child; /*!< graph child node */ que_t* graph; /*!< graph where this node belongs */ ibool is_active; /*!< TRUE if the thread has been set to the run state in que_thr_move_to_run_state, but not deactivated in que_thr_dec_reference_count */ ulint state; /*!< state of the query thread */ UT_LIST_NODE_T(que_thr_t) thrs; /*!< list of thread nodes of the fork node */ UT_LIST_NODE_T(que_thr_t) trx_thrs; /*!< lists of threads in wait list of the trx */ UT_LIST_NODE_T(que_thr_t) queue; /*!< list of runnable thread nodes in the server task queue */ /*------------------------------*/ /* The following fields are private to the OS thread executing the query thread, and are not protected by the kernel mutex: */
que_node_t* run_node; /*!< pointer to the node where the subgraph down from this node is currently executed */ que_node_t* prev_node; /*!< pointer to the node from which the control came */ ulint resource; /*!< resource usage of the query thread thus far */ ulint lock_state; /*!< lock state of thread (table or row) */ ulint fk_cascade_depth; /*!< maximum cascading call depth supported for foreign key constraint related delete/updates */ };
#define QUE_THR_MAGIC_N 8476583 #define QUE_THR_MAGIC_FREED 123461526
/* Query graph fork node: its fields are protected by the kernel mutex */ struct que_fork_struct{ que_common_t common; /*!< type: QUE_NODE_FORK */ que_t* graph; /*!< query graph of this node */ ulint fork_type; /*!< fork type */ ulint n_active_thrs; /*!< if this is the root of a graph, the number query threads that have been started in que_thr_move_to_run_state but for which que_thr_dec_refer_count has not yet been called */ trx_t* trx; /*!< transaction: this is set only in the root node */ ulint state; /*!< state of the fork node */ que_thr_t* caller; /*!< pointer to a possible calling query thread */ UT_LIST_BASE_NODE_T(que_thr_t) thrs; /*!< list of query threads */ /*------------------------------*/ /* The fields in this section are defined only in the root node */ sym_tab_t* sym_tab; /*!< symbol table of the query, generated by the parser, or NULL if the graph was created 'by hand' */ pars_info_t* info; /*!< info struct, or NULL */ /* The following cur_... fields are relevant only in a select graph */
ulint cur_end; /*!< QUE_CUR_NOT_DEFINED, QUE_CUR_START, QUE_CUR_END */ ulint cur_pos; /*!< if there are n rows in the result set, values 0 and n + 1 mean before first row, or after last row, depending on cur_end; values 1...n mean a row index */ ibool cur_on_row; /*!< TRUE if cursor is on a row, i.e., it is not before the first row or after the last row */ sel_node_t* last_sel_node; /*!< last executed select node, or NULL if none */ UT_LIST_NODE_T(que_fork_t) graphs; /*!< list of query graphs of a session or a stored procedure */ /*------------------------------*/ mem_heap_t* heap; /*!< memory heap where the fork was created */
};
/* Query graph node types */ #define QUE_NODE_LOCK 1 #define QUE_NODE_INSERT 2 #define QUE_NODE_UPDATE 4 #define QUE_NODE_CURSOR 5 #define QUE_NODE_SELECT 6 #define QUE_NODE_AGGREGATE 7 #define QUE_NODE_FORK 8 #define QUE_NODE_THR 9 #define QUE_NODE_UNDO 10 #define QUE_NODE_COMMIT 11 #define QUE_NODE_ROLLBACK 12 #define QUE_NODE_PURGE 13 #define QUE_NODE_CREATE_TABLE 14 #define QUE_NODE_CREATE_INDEX 15 #define QUE_NODE_SYMBOL 16 #define QUE_NODE_RES_WORD 17 #define QUE_NODE_FUNC 18 #define QUE_NODE_ORDER 19 #define QUE_NODE_PROC (20 + QUE_NODE_CONTROL_STAT) #define QUE_NODE_IF (21 + QUE_NODE_CONTROL_STAT) #define QUE_NODE_WHILE (22 + QUE_NODE_CONTROL_STAT) #define QUE_NODE_ASSIGNMENT 23 #define QUE_NODE_FETCH 24 #define QUE_NODE_OPEN 25 #define QUE_NODE_COL_ASSIGNMENT 26 #define QUE_NODE_FOR (27 + QUE_NODE_CONTROL_STAT) #define QUE_NODE_RETURN 28 #define QUE_NODE_ROW_PRINTF 29 #define QUE_NODE_ELSIF 30 #define QUE_NODE_CALL 31 #define QUE_NODE_EXIT 32
/* Insert node structure */
struct ins_node_struct{ que_common_t common; /*!< node type: QUE_NODE_INSERT */ ulint ins_type;/* INS_VALUES, INS_SEARCHED, or INS_DIRECT */ dtuple_t* row; /*!< row to insert */ dict_table_t* table; /*!< table where to insert */ sel_node_t* select; /*!< select in searched insert */ que_node_t* values_list;/* list of expressions to evaluate and insert in an INS_VALUES insert */ ulint state; /*!< node execution state */ dict_index_t* index; /*!< NULL, or the next index where the index entry should be inserted */ dtuple_t* entry; /*!< NULL, or entry to insert in the index; after a successful insert of the entry, this should be reset to NULL */ UT_LIST_BASE_NODE_T(dtuple_t) entry_list;/* list of entries, one for each index */ byte* row_id_buf;/* buffer for the row id sys field in row */ trx_id_t trx_id; /*!< trx id or the last trx which executed the node */ byte* trx_id_buf;/* buffer for the trx id sys field in row */ mem_heap_t* entry_sys_heap; /* memory heap used as auxiliary storage; entry_list and sys fields are stored here; if this is NULL, entry list should be created and buffers for sys fields in row allocated */ ulint magic_n; };
/** Select statement node */ struct sel_node_struct{ que_common_t common; /*!< node type: QUE_NODE_SELECT */ enum sel_node_state state; /*!< node state */ que_node_t* select_list; /*!< select list */ sym_node_t* into_list; /*!< variables list or NULL */ sym_node_t* table_list; /*!< table list */ ibool asc; /*!< TRUE if the rows should be fetched in an ascending order */ ibool set_x_locks; /*!< TRUE if the cursor is for update or delete, which means that a row x-lock should be placed on the cursor row */ ulint row_lock_mode; /*!< LOCK_X or LOCK_S */ ulint n_tables; /*!< number of tables */ ulint fetch_table; /*!< number of the next table to access in the join */ plan_t* plans; /*!< array of n_tables many plan nodes containing the search plan and the search data structures */ que_node_t* search_cond; /*!< search condition */ read_view_t* read_view; /*!< if the query is a non-locking consistent read, its read view is placed here, otherwise NULL */ ibool consistent_read;/*!< TRUE if the select is a consistent, non-locking read */ order_node_t* order_by; /*!< order by column definition, or NULL */ ibool is_aggregate; /*!< TRUE if the select list consists of aggregate functions */ ibool aggregate_already_fetched; /*!< TRUE if the aggregate row has already been fetched for the current cursor */ ibool can_get_updated;/*!< this is TRUE if the select is in a single-table explicit cursor which can get updated within the stored procedure, or in a searched update or delete; NOTE that to determine of an explicit cursor if it can get updated, the parser checks from a stored procedure if it contains positioned update or delete statements */ sym_node_t* explicit_cursor;/*!< not NULL if an explicit cursor */ UT_LIST_BASE_NODE_T(sym_node_t) copy_variables; /*!< variables whose values we have to copy when an explicit cursor is opened, so that they do not change between fetches */ };
/** Commit command node in a query graph */
struct commit_node_struct{
que_common_t common; /*!< node type: QUE_NODE_COMMIT */
enum commit_node_state
state; /*!< node execution state */
}; /* Index create node struct */
struct ind_node_struct{ que_common_t common; /*!< node type: QUE_NODE_INDEX_CREATE */ dict_index_t* index; /*!< index to create, built as a memory data structure with dict_mem_... functions */ ins_node_t* ind_def; /* child node which does the insert of the index definition; the row to be inserted is built by the parent node */ ins_node_t* field_def; /* child node which does the inserts of the field definitions; the row to be inserted is built by the parent node */ commit_node_t* commit_node; /* child node which performs a commit after a successful index creation */ /*----------------------*/ /* Local storage for this graph node */ ulint state; /*!< node execution state */ ulint page_no;/* root page number of the index */ dict_table_t* table; /*!< table which owns the index */ dtuple_t* ind_row;/* index definition row built */ ulint field_no;/* next field definition to insert */ mem_heap_t* heap; /*!< memory heap used as auxiliary storage */ };
Query graph fork node 可有多个 Query graph query thread node， 并行查询