/***************************************************************************** Copyright (c) 1996, 2009, Innobase Oy. All Rights Reserved. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA *****************************************************************************/ /**************************************************//** @file row/row0ins.c Insert into a table Created 4/20/1996 Heikki Tuuri *******************************************************/ #include "row0ins.h" #ifdef UNIV_NONINL #include "row0ins.ic" #endif #include "ha_prototypes.h" #include "dict0dict.h" #include "dict0boot.h" #include "trx0undo.h" #include "btr0btr.h" #include "btr0cur.h" #include "mach0data.h" #include "que0que.h" #include "row0upd.h" #include "row0sel.h" #include "row0row.h" #include "rem0cmp.h" #include "lock0lock.h" #include "log0log.h" #include "eval0eval.h" #include "data0data.h" #include "usr0sess.h" #include "buf0lru.h" #define ROW_INS_PREV 1 #define ROW_INS_NEXT 2 /*********************************************************************//** Creates an insert node struct. @return own: insert node struct */ UNIV_INTERN ins_node_t* ins_node_create( /*============*/ ulint ins_type, /*!< in: INS_VALUES, ... */ dict_table_t* table, /*!< in: table where to insert */ mem_heap_t* heap) /*!< in: mem heap where created */ { ins_node_t* node; node = mem_heap_alloc(heap, sizeof(ins_node_t)); node->common.type = QUE_NODE_INSERT; node->ins_type = ins_type; node->state = INS_NODE_SET_IX_LOCK; node->table = table; node->index = NULL; node->entry = NULL; node->select = NULL; node->trx_id = ut_dulint_zero; node->entry_sys_heap = mem_heap_create(128); node->magic_n = INS_NODE_MAGIC_N; return(node); } /***********************************************************//** Creates an entry template for each index of a table. */ UNIV_INTERN void ins_node_create_entry_list( /*=======================*/ ins_node_t* node) /*!< in: row insert node */ { dict_index_t* index; dtuple_t* entry; ut_ad(node->entry_sys_heap); UT_LIST_INIT(node->entry_list); index = dict_table_get_first_index(node->table); while (index != NULL) { entry = row_build_index_entry(node->row, NULL, index, node->entry_sys_heap); UT_LIST_ADD_LAST(tuple_list, node->entry_list, entry); index = dict_table_get_next_index(index); } } /*****************************************************************//** Adds system field buffers to a row. */ static void row_ins_alloc_sys_fields( /*=====================*/ ins_node_t* node) /*!< in: insert node */ { dtuple_t* row; dict_table_t* table; mem_heap_t* heap; const dict_col_t* col; dfield_t* dfield; byte* ptr; row = node->row; table = node->table; heap = node->entry_sys_heap; ut_ad(row && table && heap); ut_ad(dtuple_get_n_fields(row) == dict_table_get_n_cols(table)); /* 1. Allocate buffer for row id */ col = dict_table_get_sys_col(table, DATA_ROW_ID); dfield = dtuple_get_nth_field(row, dict_col_get_no(col)); ptr = mem_heap_zalloc(heap, DATA_ROW_ID_LEN); dfield_set_data(dfield, ptr, DATA_ROW_ID_LEN); node->row_id_buf = ptr; /* 3. Allocate buffer for trx id */ col = dict_table_get_sys_col(table, DATA_TRX_ID); dfield = dtuple_get_nth_field(row, dict_col_get_no(col)); ptr = mem_heap_zalloc(heap, DATA_TRX_ID_LEN); dfield_set_data(dfield, ptr, DATA_TRX_ID_LEN); node->trx_id_buf = ptr; /* 4. Allocate buffer for roll ptr */ col = dict_table_get_sys_col(table, DATA_ROLL_PTR); dfield = dtuple_get_nth_field(row, dict_col_get_no(col)); ptr = mem_heap_zalloc(heap, DATA_ROLL_PTR_LEN); dfield_set_data(dfield, ptr, DATA_ROLL_PTR_LEN); } /*********************************************************************//** Sets a new row to insert for an INS_DIRECT node. This function is only used if we have constructed the row separately, which is a rare case; this function is quite slow. */ UNIV_INTERN void ins_node_set_new_row( /*=================*/ ins_node_t* node, /*!< in: insert node */ dtuple_t* row) /*!< in: new row (or first row) for the node */ { node->state = INS_NODE_SET_IX_LOCK; node->index = NULL; node->entry = NULL; node->row = row; mem_heap_empty(node->entry_sys_heap); /* Create templates for index entries */ ins_node_create_entry_list(node); /* Allocate from entry_sys_heap buffers for sys fields */ row_ins_alloc_sys_fields(node); /* As we allocated a new trx id buf, the trx id should be written there again: */ node->trx_id = ut_dulint_zero; } /*******************************************************************//** Does an insert operation by updating a delete-marked existing record in the index. This situation can occur if the delete-marked record is kept in the index for consistent reads. @return DB_SUCCESS or error code */ static ulint row_ins_sec_index_entry_by_modify( /*==============================*/ ulint mode, /*!< in: BTR_MODIFY_LEAF or BTR_MODIFY_TREE, depending on whether mtr holds just a leaf latch or also a tree latch */ btr_cur_t* cursor, /*!< in: B-tree cursor */ const dtuple_t* entry, /*!< in: index entry to insert */ que_thr_t* thr, /*!< in: query thread */ mtr_t* mtr) /*!< in: mtr; must be committed before latching any further pages */ { big_rec_t* dummy_big_rec; mem_heap_t* heap; upd_t* update; rec_t* rec; ulint err; rec = btr_cur_get_rec(cursor); ut_ad(!dict_index_is_clust(cursor->index)); ut_ad(rec_get_deleted_flag(rec, dict_table_is_comp(cursor->index->table))); /* We know that in the alphabetical ordering, entry and rec are identified. But in their binary form there may be differences if there are char fields in them. Therefore we have to calculate the difference. */ heap = mem_heap_create(1024); update = row_upd_build_sec_rec_difference_binary( cursor->index, entry, rec, thr_get_trx(thr), heap); if (mode == BTR_MODIFY_LEAF) { /* Try an optimistic updating of the record, keeping changes within the page */ err = btr_cur_optimistic_update(BTR_KEEP_SYS_FLAG, cursor, update, 0, thr, mtr); switch (err) { case DB_OVERFLOW: case DB_UNDERFLOW: case DB_ZIP_OVERFLOW: err = DB_FAIL; } } else { ut_a(mode == BTR_MODIFY_TREE); if (buf_LRU_buf_pool_running_out()) { err = DB_LOCK_TABLE_FULL; goto func_exit; } err = btr_cur_pessimistic_update(BTR_KEEP_SYS_FLAG, cursor, &heap, &dummy_big_rec, update, 0, thr, mtr); ut_ad(!dummy_big_rec); } func_exit: mem_heap_free(heap); return(err); } /*******************************************************************//** Does an insert operation by delete unmarking and updating a delete marked existing record in the index. This situation can occur if the delete marked record is kept in the index for consistent reads. @return DB_SUCCESS, DB_FAIL, or error code */ static ulint row_ins_clust_index_entry_by_modify( /*================================*/ ulint mode, /*!< in: BTR_MODIFY_LEAF or BTR_MODIFY_TREE, depending on whether mtr holds just a leaf latch or also a tree latch */ btr_cur_t* cursor, /*!< in: B-tree cursor */ mem_heap_t** heap, /*!< in/out: pointer to memory heap, or NULL */ big_rec_t** big_rec,/*!< out: possible big rec vector of fields which have to be stored externally by the caller */ const dtuple_t* entry, /*!< in: index entry to insert */ que_thr_t* thr, /*!< in: query thread */ mtr_t* mtr) /*!< in: mtr; must be committed before latching any further pages */ { rec_t* rec; upd_t* update; ulint err; ut_ad(dict_index_is_clust(cursor->index)); *big_rec = NULL; rec = btr_cur_get_rec(cursor); ut_ad(rec_get_deleted_flag(rec, dict_table_is_comp(cursor->index->table))); if (!*heap) { *heap = mem_heap_create(1024); } /* Build an update vector containing all the fields to be modified; NOTE that this vector may NOT contain system columns trx_id or roll_ptr */ update = row_upd_build_difference_binary(cursor->index, entry, rec, thr_get_trx(thr), *heap); if (mode == BTR_MODIFY_LEAF) { /* Try optimistic updating of the record, keeping changes within the page */ err = btr_cur_optimistic_update(0, cursor, update, 0, thr, mtr); switch (err) { case DB_OVERFLOW: case DB_UNDERFLOW: case DB_ZIP_OVERFLOW: err = DB_FAIL; } } else { ut_a(mode == BTR_MODIFY_TREE); if (buf_LRU_buf_pool_running_out()) { return(DB_LOCK_TABLE_FULL); } err = btr_cur_pessimistic_update(0, cursor, heap, big_rec, update, 0, thr, mtr); } return(err); } /*********************************************************************//** Returns TRUE if in a cascaded update/delete an ancestor node of node updates (not DELETE, but UPDATE) table. @return TRUE if an ancestor updates table */ static ibool row_ins_cascade_ancestor_updates_table( /*===================================*/ que_node_t* node, /*!< in: node in a query graph */ dict_table_t* table) /*!< in: table */ { que_node_t* parent; upd_node_t* upd_node; parent = que_node_get_parent(node); while (que_node_get_type(parent) == QUE_NODE_UPDATE) { upd_node = parent; if (upd_node->table == table && upd_node->is_delete == FALSE) { return(TRUE); } parent = que_node_get_parent(parent); ut_a(parent); } return(FALSE); } /*********************************************************************//** Returns the number of ancestor UPDATE or DELETE nodes of a cascaded update/delete node. @return number of ancestors */ static ulint row_ins_cascade_n_ancestors( /*========================*/ que_node_t* node) /*!< in: node in a query graph */ { que_node_t* parent; ulint n_ancestors = 0; parent = que_node_get_parent(node); while (que_node_get_type(parent) == QUE_NODE_UPDATE) { n_ancestors++; parent = que_node_get_parent(parent); ut_a(parent); } return(n_ancestors); } /******************************************************************//** Calculates the update vector node->cascade->update for a child table in a cascaded update. @return number of fields in the calculated update vector; the value can also be 0 if no foreign key fields changed; the returned value is ULINT_UNDEFINED if the column type in the child table is too short to fit the new value in the parent table: that means the update fails */ static ulint row_ins_cascade_calc_update_vec( /*============================*/ upd_node_t* node, /*!< in: update node of the parent table */ dict_foreign_t* foreign, /*!< in: foreign key constraint whose type is != 0 */ mem_heap_t* heap) /*!< in: memory heap to use as temporary storage */ { upd_node_t* cascade = node->cascade_node; dict_table_t* table = foreign->foreign_table; dict_index_t* index = foreign->foreign_index; upd_t* update; upd_field_t* ufield; dict_table_t* parent_table; dict_index_t* parent_index; upd_t* parent_update; upd_field_t* parent_ufield; ulint n_fields_updated; ulint parent_field_no; ulint i; ulint j; ut_a(node); ut_a(foreign); ut_a(cascade); ut_a(table); ut_a(index); /* Calculate the appropriate update vector which will set the fields in the child index record to the same value (possibly padded with spaces if the column is a fixed length CHAR or FIXBINARY column) as the referenced index record will get in the update. */ parent_table = node->table; ut_a(parent_table == foreign->referenced_table); parent_index = foreign->referenced_index; parent_update = node->update; update = cascade->update; update->info_bits = 0; update->n_fields = foreign->n_fields; n_fields_updated = 0; for (i = 0; i < foreign->n_fields; i++) { parent_field_no = dict_table_get_nth_col_pos( parent_table, dict_index_get_nth_col_no(parent_index, i)); for (j = 0; j < parent_update->n_fields; j++) { parent_ufield = parent_update->fields + j; if (parent_ufield->field_no == parent_field_no) { ulint min_size; const dict_col_t* col; ulint ufield_len; col = dict_index_get_nth_col(index, i); /* A field in the parent index record is updated. Let us make the update vector field for the child table. */ ufield = update->fields + n_fields_updated; ufield->field_no = dict_table_get_nth_col_pos( table, dict_col_get_no(col)); ufield->exp = NULL; ufield->new_val = parent_ufield->new_val; ufield_len = dfield_get_len(&ufield->new_val); /* Clear the "external storage" flag */ dfield_set_len(&ufield->new_val, ufield_len); /* Do not allow a NOT NULL column to be updated as NULL */ if (dfield_is_null(&ufield->new_val) && (col->prtype & DATA_NOT_NULL)) { return(ULINT_UNDEFINED); } /* If the new value would not fit in the column, do not allow the update */ if (!dfield_is_null(&ufield->new_val) && dtype_get_at_most_n_mbchars( col->prtype, col->mbminlen, col->mbmaxlen, col->len, ufield_len, dfield_get_data(&ufield->new_val)) < ufield_len) { return(ULINT_UNDEFINED); } /* If the parent column type has a different length than the child column type, we may need to pad with spaces the new value of the child column */ min_size = dict_col_get_min_size(col); /* Because UNIV_SQL_NULL (the marker of SQL NULL values) exceeds all possible values of min_size, the test below will not hold for SQL NULL columns. */ if (min_size > ufield_len) { char* pad_start; const char* pad_end; char* padded_data = mem_heap_alloc( heap, min_size); pad_start = padded_data + ufield_len; pad_end = padded_data + min_size; memcpy(padded_data, dfield_get_data(&ufield ->new_val), dfield_get_len(&ufield ->new_val)); switch (UNIV_EXPECT(col->mbminlen,1)) { default: ut_error; return(ULINT_UNDEFINED); case 1: if (UNIV_UNLIKELY (dtype_get_charset_coll( col->prtype) == DATA_MYSQL_BINARY_CHARSET_COLL)) { /* Do not pad BINARY columns. */ return(ULINT_UNDEFINED); } /* space=0x20 */ memset(pad_start, 0x20, pad_end - pad_start); break; case 2: /* space=0x0020 */ ut_a(!(ufield_len % 2)); ut_a(!(min_size % 2)); do { *pad_start++ = 0x00; *pad_start++ = 0x20; } while (pad_start < pad_end); break; } dfield_set_data(&ufield->new_val, padded_data, min_size); } n_fields_updated++; } } } update->n_fields = n_fields_updated; return(n_fields_updated); } /*********************************************************************//** Set detailed error message associated with foreign key errors for the given transaction. */ static void row_ins_set_detailed( /*=================*/ trx_t* trx, /*!< in: transaction */ dict_foreign_t* foreign) /*!< in: foreign key constraint */ { mutex_enter(&srv_misc_tmpfile_mutex); rewind(srv_misc_tmpfile); if (os_file_set_eof(srv_misc_tmpfile)) { ut_print_name(srv_misc_tmpfile, trx, TRUE, foreign->foreign_table_name); dict_print_info_on_foreign_key_in_create_format( srv_misc_tmpfile, trx, foreign, FALSE); trx_set_detailed_error_from_file(trx, srv_misc_tmpfile); } else { trx_set_detailed_error(trx, "temp file operation failed"); } mutex_exit(&srv_misc_tmpfile_mutex); } /*********************************************************************//** Reports a foreign key error associated with an update or a delete of a parent table index entry. */ static void row_ins_foreign_report_err( /*=======================*/ const char* errstr, /*!< in: error string from the viewpoint of the parent table */ que_thr_t* thr, /*!< in: query thread whose run_node is an update node */ dict_foreign_t* foreign, /*!< in: foreign key constraint */ const rec_t* rec, /*!< in: a matching index record in the child table */ const dtuple_t* entry) /*!< in: index entry in the parent table */ { FILE* ef = dict_foreign_err_file; trx_t* trx = thr_get_trx(thr); row_ins_set_detailed(trx, foreign); mutex_enter(&dict_foreign_err_mutex); rewind(ef); ut_print_timestamp(ef); fputs(" Transaction:\n", ef); trx_print(ef, trx, 600); fputs("Foreign key constraint fails for table ", ef); ut_print_name(ef, trx, TRUE, foreign->foreign_table_name); fputs(":\n", ef); dict_print_info_on_foreign_key_in_create_format(ef, trx, foreign, TRUE); putc('\n', ef); fputs(errstr, ef); fputs(" in parent table, in index ", ef); ut_print_name(ef, trx, FALSE, foreign->referenced_index->name); if (entry) { fputs(" tuple:\n", ef); dtuple_print(ef, entry); } fputs("\nBut in child table ", ef); ut_print_name(ef, trx, TRUE, foreign->foreign_table_name); fputs(", in index ", ef); ut_print_name(ef, trx, FALSE, foreign->foreign_index->name); if (rec) { fputs(", there is a record:\n", ef); rec_print(ef, rec, foreign->foreign_index); } else { fputs(", the record is not available\n", ef); } putc('\n', ef); mutex_exit(&dict_foreign_err_mutex); } /*********************************************************************//** Reports a foreign key error to dict_foreign_err_file when we are trying to add an index entry to a child table. Note that the adding may be the result of an update, too. */ static void row_ins_foreign_report_add_err( /*===========================*/ trx_t* trx, /*!< in: transaction */ dict_foreign_t* foreign, /*!< in: foreign key constraint */ const rec_t* rec, /*!< in: a record in the parent table: it does not match entry because we have an error! */ const dtuple_t* entry) /*!< in: index entry to insert in the child table */ { FILE* ef = dict_foreign_err_file; row_ins_set_detailed(trx, foreign); mutex_enter(&dict_foreign_err_mutex); rewind(ef); ut_print_timestamp(ef); fputs(" Transaction:\n", ef); trx_print(ef, trx, 600); fputs("Foreign key constraint fails for table ", ef); ut_print_name(ef, trx, TRUE, foreign->foreign_table_name); fputs(":\n", ef); dict_print_info_on_foreign_key_in_create_format(ef, trx, foreign, TRUE); fputs("\nTrying to add in child table, in index ", ef); ut_print_name(ef, trx, FALSE, foreign->foreign_index->name); if (entry) { fputs(" tuple:\n", ef); /* TODO: DB_TRX_ID and DB_ROLL_PTR may be uninitialized. It would be better to only display the user columns. */ dtuple_print(ef, entry); } fputs("\nBut in parent table ", ef); ut_print_name(ef, trx, TRUE, foreign->referenced_table_name); fputs(", in index ", ef); ut_print_name(ef, trx, FALSE, foreign->referenced_index->name); fputs(",\nthe closest match we can find is record:\n", ef); if (rec && page_rec_is_supremum(rec)) { /* If the cursor ended on a supremum record, it is better to report the previous record in the error message, so that the user gets a more descriptive error message. */ rec = page_rec_get_prev_const(rec); } if (rec) { rec_print(ef, rec, foreign->referenced_index); } putc('\n', ef); mutex_exit(&dict_foreign_err_mutex); } /*********************************************************************//** Invalidate the query cache for the given table. */ static void row_ins_invalidate_query_cache( /*===========================*/ que_thr_t* thr, /*!< in: query thread whose run_node is an update node */ const char* name) /*!< in: table name prefixed with database name and a '/' character */ { char* buf; char* ptr; ulint len = strlen(name) + 1; buf = mem_strdupl(name, len); ptr = strchr(buf, '/'); ut_a(ptr); *ptr = '\0'; innobase_invalidate_query_cache(thr_get_trx(thr), buf, len); mem_free(buf); } /*********************************************************************//** Perform referential actions or checks when a parent row is deleted or updated and the constraint had an ON DELETE or ON UPDATE condition which was not RESTRICT. @return DB_SUCCESS, DB_LOCK_WAIT, or error code */ static ulint row_ins_foreign_check_on_constraint( /*================================*/ que_thr_t* thr, /*!< in: query thread whose run_node is an update node */ dict_foreign_t* foreign, /*!< in: foreign key constraint whose type is != 0 */ btr_pcur_t* pcur, /*!< in: cursor placed on a matching index record in the child table */ dtuple_t* entry, /*!< in: index entry in the parent table */ mtr_t* mtr) /*!< in: mtr holding the latch of pcur page */ { upd_node_t* node; upd_node_t* cascade; dict_table_t* table = foreign->foreign_table; dict_index_t* index; dict_index_t* clust_index; dtuple_t* ref; mem_heap_t* upd_vec_heap = NULL; const rec_t* rec; const rec_t* clust_rec; const buf_block_t* clust_block; upd_t* update; ulint n_to_update; ulint err; ulint i; trx_t* trx; mem_heap_t* tmp_heap = NULL; ut_a(thr); ut_a(foreign); ut_a(pcur); ut_a(mtr); trx = thr_get_trx(thr); /* Since we are going to delete or update a row, we have to invalidate the MySQL query cache for table. A deadlock of threads is not possible here because the caller of this function does not hold any latches with the sync0sync.h rank above the kernel mutex. The query cache mutex has a rank just above the kernel mutex. */ row_ins_invalidate_query_cache(thr, table->name); node = thr->run_node; if (node->is_delete && 0 == (foreign->type & (DICT_FOREIGN_ON_DELETE_CASCADE | DICT_FOREIGN_ON_DELETE_SET_NULL))) { row_ins_foreign_report_err("Trying to delete", thr, foreign, btr_pcur_get_rec(pcur), entry); return(DB_ROW_IS_REFERENCED); } if (!node->is_delete && 0 == (foreign->type & (DICT_FOREIGN_ON_UPDATE_CASCADE | DICT_FOREIGN_ON_UPDATE_SET_NULL))) { /* This is an UPDATE */ row_ins_foreign_report_err("Trying to update", thr, foreign, btr_pcur_get_rec(pcur), entry); return(DB_ROW_IS_REFERENCED); } if (node->cascade_node == NULL) { /* Extend our query graph by creating a child to current update node. The child is used in the cascade or set null operation. */ node->cascade_heap = mem_heap_create(128); node->cascade_node = row_create_update_node_for_mysql( table, node->cascade_heap); que_node_set_parent(node->cascade_node, node); } /* Initialize cascade_node to do the operation we want. Note that we use the SAME cascade node to do all foreign key operations of the SQL DELETE: the table of the cascade node may change if there are several child tables to the table where the delete is done! */ cascade = node->cascade_node; cascade->table = table; cascade->foreign = foreign; if (node->is_delete && (foreign->type & DICT_FOREIGN_ON_DELETE_CASCADE)) { cascade->is_delete = TRUE; } else { cascade->is_delete = FALSE; if (foreign->n_fields > cascade->update_n_fields) { /* We have to make the update vector longer */ cascade->update = upd_create(foreign->n_fields, node->cascade_heap); cascade->update_n_fields = foreign->n_fields; } } /* We do not allow cyclic cascaded updating (DELETE is allowed, but not UPDATE) of the same table, as this can lead to an infinite cycle. Check that we are not updating the same table which is already being modified in this cascade chain. We have to check this also because the modification of the indexes of a 'parent' table may still be incomplete, and we must avoid seeing the indexes of the parent table in an inconsistent state! */ if (!cascade->is_delete && row_ins_cascade_ancestor_updates_table(cascade, table)) { /* We do not know if this would break foreign key constraints, but play safe and return an error */ err = DB_ROW_IS_REFERENCED; row_ins_foreign_report_err( "Trying an update, possibly causing a cyclic" " cascaded update\n" "in the child table,", thr, foreign, btr_pcur_get_rec(pcur), entry); goto nonstandard_exit_func; } if (row_ins_cascade_n_ancestors(cascade) >= 15) { err = DB_ROW_IS_REFERENCED; row_ins_foreign_report_err( "Trying a too deep cascaded delete or update\n", thr, foreign, btr_pcur_get_rec(pcur), entry); goto nonstandard_exit_func; } index = btr_pcur_get_btr_cur(pcur)->index; ut_a(index == foreign->foreign_index); rec = btr_pcur_get_rec(pcur); if (dict_index_is_clust(index)) { /* pcur is already positioned in the clustered index of the child table */ clust_index = index; clust_rec = rec; clust_block = btr_pcur_get_block(pcur); } else { /* We have to look for the record in the clustered index in the child table */ clust_index = dict_table_get_first_index(table); tmp_heap = mem_heap_create(256); ref = row_build_row_ref(ROW_COPY_POINTERS, index, rec, tmp_heap); btr_pcur_open_with_no_init(clust_index, ref, PAGE_CUR_LE, BTR_SEARCH_LEAF, cascade->pcur, 0, mtr); clust_rec = btr_pcur_get_rec(cascade->pcur); clust_block = btr_pcur_get_block(cascade->pcur); if (!page_rec_is_user_rec(clust_rec) || btr_pcur_get_low_match(cascade->pcur) < dict_index_get_n_unique(clust_index)) { fputs("InnoDB: error in cascade of a foreign key op\n" "InnoDB: ", stderr); dict_index_name_print(stderr, trx, index); fputs("\n" "InnoDB: record ", stderr); rec_print(stderr, rec, index); fputs("\n" "InnoDB: clustered record ", stderr); rec_print(stderr, clust_rec, clust_index); fputs("\n" "InnoDB: Submit a detailed bug report to" " http://bugs.mysql.com\n", stderr); err = DB_SUCCESS; goto nonstandard_exit_func; } } /* Set an X-lock on the row to delete or update in the child table */ err = lock_table(0, table, LOCK_IX, thr); if (err == DB_SUCCESS) { /* Here it suffices to use a LOCK_REC_NOT_GAP type lock; we already have a normal shared lock on the appropriate gap if the search criterion was not unique */ err = lock_clust_rec_read_check_and_lock_alt( 0, clust_block, clust_rec, clust_index, LOCK_X, LOCK_REC_NOT_GAP, thr); } if (err != DB_SUCCESS) { goto nonstandard_exit_func; } if (rec_get_deleted_flag(clust_rec, dict_table_is_comp(table))) { /* This can happen if there is a circular reference of rows such that cascading delete comes to delete a row already in the process of being delete marked */ err = DB_SUCCESS; goto nonstandard_exit_func; } if ((node->is_delete && (foreign->type & DICT_FOREIGN_ON_DELETE_SET_NULL)) || (!node->is_delete && (foreign->type & DICT_FOREIGN_ON_UPDATE_SET_NULL))) { /* Build the appropriate update vector which sets foreign->n_fields first fields in rec to SQL NULL */ update = cascade->update; update->info_bits = 0; update->n_fields = foreign->n_fields; for (i = 0; i < foreign->n_fields; i++) { upd_field_t* ufield = &update->fields[i]; ufield->field_no = dict_table_get_nth_col_pos( table, dict_index_get_nth_col_no(index, i)); ufield->orig_len = 0; ufield->exp = NULL; dfield_set_null(&ufield->new_val); } } if (!node->is_delete && (foreign->type & DICT_FOREIGN_ON_UPDATE_CASCADE)) { /* Build the appropriate update vector which sets changing foreign->n_fields first fields in rec to new values */ upd_vec_heap = mem_heap_create(256); n_to_update = row_ins_cascade_calc_update_vec(node, foreign, upd_vec_heap); if (n_to_update == ULINT_UNDEFINED) { err = DB_ROW_IS_REFERENCED; row_ins_foreign_report_err( "Trying a cascaded update where the" " updated value in the child\n" "table would not fit in the length" " of the column, or the value would\n" "be NULL and the column is" " declared as not NULL in the child table,", thr, foreign, btr_pcur_get_rec(pcur), entry); goto nonstandard_exit_func; } if (cascade->update->n_fields == 0) { /* The update does not change any columns referred to in this foreign key constraint: no need to do anything */ err = DB_SUCCESS; goto nonstandard_exit_func; } } /* Store pcur position and initialize or store the cascade node pcur stored position */ btr_pcur_store_position(pcur, mtr); if (index == clust_index) { btr_pcur_copy_stored_position(cascade->pcur, pcur); } else { btr_pcur_store_position(cascade->pcur, mtr); } mtr_commit(mtr); ut_a(cascade->pcur->rel_pos == BTR_PCUR_ON); cascade->state = UPD_NODE_UPDATE_CLUSTERED; err = row_update_cascade_for_mysql(thr, cascade, foreign->foreign_table); if (foreign->foreign_table->n_foreign_key_checks_running == 0) { fprintf(stderr, "InnoDB: error: table %s has the counter 0" " though there is\n" "InnoDB: a FOREIGN KEY check running on it.\n", foreign->foreign_table->name); } /* Release the data dictionary latch for a while, so that we do not starve other threads from doing CREATE TABLE etc. if we have a huge cascaded operation running. The counter n_foreign_key_checks_running will prevent other users from dropping or ALTERing the table when we release the latch. */ row_mysql_unfreeze_data_dictionary(thr_get_trx(thr)); row_mysql_freeze_data_dictionary(thr_get_trx(thr)); mtr_start(mtr); /* Restore pcur position */ btr_pcur_restore_position(BTR_SEARCH_LEAF, pcur, mtr); if (tmp_heap) { mem_heap_free(tmp_heap); } if (upd_vec_heap) { mem_heap_free(upd_vec_heap); } return(err); nonstandard_exit_func: if (tmp_heap) { mem_heap_free(tmp_heap); } if (upd_vec_heap) { mem_heap_free(upd_vec_heap); } btr_pcur_store_position(pcur, mtr); mtr_commit(mtr); mtr_start(mtr); btr_pcur_restore_position(BTR_SEARCH_LEAF, pcur, mtr); return(err); } /*********************************************************************//** Sets a shared lock on a record. Used in locking possible duplicate key records and also in checking foreign key constraints. @return DB_SUCCESS or error code */ static ulint row_ins_set_shared_rec_lock( /*========================*/ ulint type, /*!< in: LOCK_ORDINARY, LOCK_GAP, or LOCK_REC_NOT_GAP type lock */ const buf_block_t* block, /*!< in: buffer block of rec */ const rec_t* rec, /*!< in: record */ dict_index_t* index, /*!< in: index */ const ulint* offsets,/*!< in: rec_get_offsets(rec, index) */ que_thr_t* thr) /*!< in: query thread */ { ulint err; ut_ad(rec_offs_validate(rec, index, offsets)); if (dict_index_is_clust(index)) { err = lock_clust_rec_read_check_and_lock( 0, block, rec, index, offsets, LOCK_S, type, thr); } else { err = lock_sec_rec_read_check_and_lock( 0, block, rec, index, offsets, LOCK_S, type, thr); } return(err); } /*********************************************************************//** Sets a exclusive lock on a record. Used in locking possible duplicate key records @return DB_SUCCESS or error code */ static ulint row_ins_set_exclusive_rec_lock( /*===========================*/ ulint type, /*!< in: LOCK_ORDINARY, LOCK_GAP, or LOCK_REC_NOT_GAP type lock */ const buf_block_t* block, /*!< in: buffer block of rec */ const rec_t* rec, /*!< in: record */ dict_index_t* index, /*!< in: index */ const ulint* offsets,/*!< in: rec_get_offsets(rec, index) */ que_thr_t* thr) /*!< in: query thread */ { ulint err; ut_ad(rec_offs_validate(rec, index, offsets)); if (dict_index_is_clust(index)) { err = lock_clust_rec_read_check_and_lock( 0, block, rec, index, offsets, LOCK_X, type, thr); } else { err = lock_sec_rec_read_check_and_lock( 0, block, rec, index, offsets, LOCK_X, type, thr); } return(err); } /***************************************************************//** Checks if foreign key constraint fails for an index entry. Sets shared locks which lock either the success or the failure of the constraint. NOTE that the caller must have a shared latch on dict_operation_lock. @return DB_SUCCESS, DB_NO_REFERENCED_ROW, or DB_ROW_IS_REFERENCED */ UNIV_INTERN ulint row_ins_check_foreign_constraint( /*=============================*/ ibool check_ref,/*!< in: TRUE if we want to check that the referenced table is ok, FALSE if we want to check the foreign key table */ dict_foreign_t* foreign,/*!< in: foreign constraint; NOTE that the tables mentioned in it must be in the dictionary cache if they exist at all */ dict_table_t* table, /*!< in: if check_ref is TRUE, then the foreign table, else the referenced table */ dtuple_t* entry, /*!< in: index entry for index */ que_thr_t* thr) /*!< in: query thread */ { upd_node_t* upd_node; dict_table_t* check_table; dict_index_t* check_index; ulint n_fields_cmp; btr_pcur_t pcur; ibool moved; int cmp; ulint err; ulint i; mtr_t mtr; trx_t* trx = thr_get_trx(thr); mem_heap_t* heap = NULL; ulint offsets_[REC_OFFS_NORMAL_SIZE]; ulint* offsets = offsets_; rec_offs_init(offsets_); run_again: #ifdef UNIV_SYNC_DEBUG ut_ad(rw_lock_own(&dict_operation_lock, RW_LOCK_SHARED)); #endif /* UNIV_SYNC_DEBUG */ err = DB_SUCCESS; if (trx->check_foreigns == FALSE) { /* The user has suppressed foreign key checks currently for this session */ goto exit_func; } /* If any of the foreign key fields in entry is SQL NULL, we suppress the foreign key check: this is compatible with Oracle, for example */ for (i = 0; i < foreign->n_fields; i++) { if (UNIV_SQL_NULL == dfield_get_len( dtuple_get_nth_field(entry, i))) { goto exit_func; } } if (que_node_get_type(thr->run_node) == QUE_NODE_UPDATE) { upd_node = thr->run_node; if (!(upd_node->is_delete) && upd_node->foreign == foreign) { /* If a cascaded update is done as defined by a foreign key constraint, do not check that constraint for the child row. In ON UPDATE CASCADE the update of the parent row is only half done when we come here: if we would check the constraint here for the child row it would fail. A QUESTION remains: if in the child table there are several constraints which refer to the same parent table, we should merge all updates to the child as one update? And the updates can be contradictory! Currently we just perform the update associated with each foreign key constraint, one after another, and the user has problems predicting in which order they are performed. */ goto exit_func; } } if (check_ref) { check_table = foreign->referenced_table; check_index = foreign->referenced_index; } else { check_table = foreign->foreign_table; check_index = foreign->foreign_index; } if (check_table == NULL || check_table->ibd_file_missing) { if (check_ref) { FILE* ef = dict_foreign_err_file; row_ins_set_detailed(trx, foreign); mutex_enter(&dict_foreign_err_mutex); rewind(ef); ut_print_timestamp(ef); fputs(" Transaction:\n", ef); trx_print(ef, trx, 600); fputs("Foreign key constraint fails for table ", ef); ut_print_name(ef, trx, TRUE, foreign->foreign_table_name); fputs(":\n", ef); dict_print_info_on_foreign_key_in_create_format( ef, trx, foreign, TRUE); fputs("\nTrying to add to index ", ef); ut_print_name(ef, trx, FALSE, foreign->foreign_index->name); fputs(" tuple:\n", ef); dtuple_print(ef, entry); fputs("\nBut the parent table ", ef); ut_print_name(ef, trx, TRUE, foreign->referenced_table_name); fputs("\nor its .ibd file does" " not currently exist!\n", ef); mutex_exit(&dict_foreign_err_mutex); err = DB_NO_REFERENCED_ROW; } goto exit_func; } ut_a(check_table); ut_a(check_index); if (check_table != table) { /* We already have a LOCK_IX on table, but not necessarily on check_table */ err = lock_table(0, check_table, LOCK_IS, thr); if (err != DB_SUCCESS) { goto do_possible_lock_wait; } } mtr_start(&mtr); /* Store old value on n_fields_cmp */ n_fields_cmp = dtuple_get_n_fields_cmp(entry); dtuple_set_n_fields_cmp(entry, foreign->n_fields); btr_pcur_open(check_index, entry, PAGE_CUR_GE, BTR_SEARCH_LEAF, &pcur, &mtr); /* Scan index records and check if there is a matching record */ for (;;) { const rec_t* rec = btr_pcur_get_rec(&pcur); const buf_block_t* block = btr_pcur_get_block(&pcur); if (page_rec_is_infimum(rec)) { goto next_rec; } offsets = rec_get_offsets(rec, check_index, offsets, ULINT_UNDEFINED, &heap); if (page_rec_is_supremum(rec)) { err = row_ins_set_shared_rec_lock(LOCK_ORDINARY, block, rec, check_index, offsets, thr); if (err != DB_SUCCESS) { break; } goto next_rec; } cmp = cmp_dtuple_rec(entry, rec, offsets); if (cmp == 0) { if (rec_get_deleted_flag(rec, rec_offs_comp(offsets))) { err = row_ins_set_shared_rec_lock( LOCK_ORDINARY, block, rec, check_index, offsets, thr); if (err != DB_SUCCESS) { break; } } else { /* Found a matching record. Lock only a record because we can allow inserts into gaps */ err = row_ins_set_shared_rec_lock( LOCK_REC_NOT_GAP, block, rec, check_index, offsets, thr); if (err != DB_SUCCESS) { break; } if (check_ref) { err = DB_SUCCESS; break; } else if (foreign->type != 0) { /* There is an ON UPDATE or ON DELETE condition: check them in a separate function */ err = row_ins_foreign_check_on_constraint( thr, foreign, &pcur, entry, &mtr); if (err != DB_SUCCESS) { /* Since reporting a plain "duplicate key" error message to the user in cases where a long CASCADE operation would lead to a duplicate key in some other table is very confusing, map duplicate key errors resulting from FK constraints to a separate error code. */ if (err == DB_DUPLICATE_KEY) { err = DB_FOREIGN_DUPLICATE_KEY; } break; } /* row_ins_foreign_check_on_constraint may have repositioned pcur on a different block */ block = btr_pcur_get_block(&pcur); } else { row_ins_foreign_report_err( "Trying to delete or update", thr, foreign, rec, entry); err = DB_ROW_IS_REFERENCED; break; } } } if (cmp < 0) { err = row_ins_set_shared_rec_lock( LOCK_GAP, block, rec, check_index, offsets, thr); if (err != DB_SUCCESS) { break; } if (check_ref) { err = DB_NO_REFERENCED_ROW; row_ins_foreign_report_add_err( trx, foreign, rec, entry); } else { err = DB_SUCCESS; } break; } ut_a(cmp == 0); next_rec: moved = btr_pcur_move_to_next(&pcur, &mtr); if (!moved) { if (check_ref) { rec = btr_pcur_get_rec(&pcur); row_ins_foreign_report_add_err( trx, foreign, rec, entry); err = DB_NO_REFERENCED_ROW; } else { err = DB_SUCCESS; } break; } } btr_pcur_close(&pcur); mtr_commit(&mtr); /* Restore old value */ dtuple_set_n_fields_cmp(entry, n_fields_cmp); do_possible_lock_wait: if (err == DB_LOCK_WAIT) { trx->error_state = err; que_thr_stop_for_mysql(thr); srv_suspend_mysql_thread(thr); if (trx->error_state == DB_SUCCESS) { goto run_again; } err = trx->error_state; } exit_func: if (UNIV_LIKELY_NULL(heap)) { mem_heap_free(heap); } return(err); } /***************************************************************//** Checks if foreign key constraints fail for an index entry. If index is not mentioned in any constraint, this function does nothing, Otherwise does searches to the indexes of referenced tables and sets shared locks which lock either the success or the failure of a constraint. @return DB_SUCCESS or error code */ static ulint row_ins_check_foreign_constraints( /*==============================*/ dict_table_t* table, /*!< in: table */ dict_index_t* index, /*!< in: index */ dtuple_t* entry, /*!< in: index entry for index */ que_thr_t* thr) /*!< in: query thread */ { dict_foreign_t* foreign; ulint err; trx_t* trx; ibool got_s_lock = FALSE; trx = thr_get_trx(thr); foreign = UT_LIST_GET_FIRST(table->foreign_list); while (foreign) { if (foreign->foreign_index == index) { if (foreign->referenced_table == NULL) { dict_table_get(foreign->referenced_table_name, FALSE); } if (0 == trx->dict_operation_lock_mode) { got_s_lock = TRUE; row_mysql_freeze_data_dictionary(trx); } if (foreign->referenced_table) { mutex_enter(&(dict_sys->mutex)); (foreign->referenced_table ->n_foreign_key_checks_running)++; mutex_exit(&(dict_sys->mutex)); } /* NOTE that if the thread ends up waiting for a lock we will release dict_operation_lock temporarily! But the counter on the table protects the referenced table from being dropped while the check is running. */ err = row_ins_check_foreign_constraint( TRUE, foreign, table, entry, thr); if (foreign->referenced_table) { mutex_enter(&(dict_sys->mutex)); ut_a(foreign->referenced_table ->n_foreign_key_checks_running > 0); (foreign->referenced_table ->n_foreign_key_checks_running)--; mutex_exit(&(dict_sys->mutex)); } if (got_s_lock) { row_mysql_unfreeze_data_dictionary(trx); } if (err != DB_SUCCESS) { return(err); } } foreign = UT_LIST_GET_NEXT(foreign_list, foreign); } return(DB_SUCCESS); } /***************************************************************//** Checks if a unique key violation to rec would occur at the index entry insert. @return TRUE if error */ static ibool row_ins_dupl_error_with_rec( /*========================*/ const rec_t* rec, /*!< in: user record; NOTE that we assume that the caller already has a record lock on the record! */ const dtuple_t* entry, /*!< in: entry to insert */ dict_index_t* index, /*!< in: index */ const ulint* offsets)/*!< in: rec_get_offsets(rec, index) */ { ulint matched_fields; ulint matched_bytes; ulint n_unique; ulint i; ut_ad(rec_offs_validate(rec, index, offsets)); n_unique = dict_index_get_n_unique(index); matched_fields = 0; matched_bytes = 0; cmp_dtuple_rec_with_match(entry, rec, offsets, &matched_fields, &matched_bytes); if (matched_fields < n_unique) { return(FALSE); } /* In a unique secondary index we allow equal key values if they contain SQL NULLs */ if (!dict_index_is_clust(index)) { for (i = 0; i < n_unique; i++) { if (UNIV_SQL_NULL == dfield_get_len( dtuple_get_nth_field(entry, i))) { return(FALSE); } } } return(!rec_get_deleted_flag(rec, rec_offs_comp(offsets))); } /***************************************************************//** Scans a unique non-clustered index at a given index entry to determine whether a uniqueness violation has occurred for the key value of the entry. Set shared locks on possible duplicate records. @return DB_SUCCESS, DB_DUPLICATE_KEY, or DB_LOCK_WAIT */ static ulint row_ins_scan_sec_index_for_duplicate( /*=================================*/ dict_index_t* index, /*!< in: non-clustered unique index */ dtuple_t* entry, /*!< in: index entry */ que_thr_t* thr) /*!< in: query thread */ { ulint n_unique; ulint i; int cmp; ulint n_fields_cmp; btr_pcur_t pcur; ulint err = DB_SUCCESS; unsigned allow_duplicates; mtr_t mtr; mem_heap_t* heap = NULL; ulint offsets_[REC_OFFS_NORMAL_SIZE]; ulint* offsets = offsets_; rec_offs_init(offsets_); n_unique = dict_index_get_n_unique(index); /* If the secondary index is unique, but one of the fields in the n_unique first fields is NULL, a unique key violation cannot occur, since we define NULL != NULL in this case */ for (i = 0; i < n_unique; i++) { if (UNIV_SQL_NULL == dfield_get_len( dtuple_get_nth_field(entry, i))) { return(DB_SUCCESS); } } mtr_start(&mtr); /* Store old value on n_fields_cmp */ n_fields_cmp = dtuple_get_n_fields_cmp(entry); dtuple_set_n_fields_cmp(entry, dict_index_get_n_unique(index)); btr_pcur_open(index, entry, PAGE_CUR_GE, BTR_SEARCH_LEAF, &pcur, &mtr); allow_duplicates = thr_get_trx(thr)->duplicates & TRX_DUP_IGNORE; /* Scan index records and check if there is a duplicate */ do { const rec_t* rec = btr_pcur_get_rec(&pcur); const buf_block_t* block = btr_pcur_get_block(&pcur); if (page_rec_is_infimum(rec)) { continue; } offsets = rec_get_offsets(rec, index, offsets, ULINT_UNDEFINED, &heap); if (allow_duplicates) { /* If the SQL-query will update or replace duplicate key we will take X-lock for duplicates ( REPLACE, LOAD DATAFILE REPLACE, INSERT ON DUPLICATE KEY UPDATE). */ err = row_ins_set_exclusive_rec_lock( LOCK_ORDINARY, block, rec, index, offsets, thr); } else { err = row_ins_set_shared_rec_lock( LOCK_ORDINARY, block, rec, index, offsets, thr); } if (err != DB_SUCCESS) { break; } if (page_rec_is_supremum(rec)) { continue; } cmp = cmp_dtuple_rec(entry, rec, offsets); if (cmp == 0) { if (row_ins_dupl_error_with_rec(rec, entry, index, offsets)) { err = DB_DUPLICATE_KEY; thr_get_trx(thr)->error_info = index; break; } } if (cmp < 0) { break; } ut_a(cmp == 0); } while (btr_pcur_move_to_next(&pcur, &mtr)); if (UNIV_LIKELY_NULL(heap)) { mem_heap_free(heap); } mtr_commit(&mtr); /* Restore old value */ dtuple_set_n_fields_cmp(entry, n_fields_cmp); return(err); } /***************************************************************//** Checks if a unique key violation error would occur at an index entry insert. Sets shared locks on possible duplicate records. Works only for a clustered index! @return DB_SUCCESS if no error, DB_DUPLICATE_KEY if error, DB_LOCK_WAIT if we have to wait for a lock on a possible duplicate record */ static ulint row_ins_duplicate_error_in_clust( /*=============================*/ btr_cur_t* cursor, /*!< in: B-tree cursor */ dtuple_t* entry, /*!< in: entry to insert */ que_thr_t* thr, /*!< in: query thread */ mtr_t* mtr) /*!< in: mtr */ { ulint err; rec_t* rec; ulint n_unique; trx_t* trx = thr_get_trx(thr); mem_heap_t*heap = NULL; ulint offsets_[REC_OFFS_NORMAL_SIZE]; ulint* offsets = offsets_; rec_offs_init(offsets_); UT_NOT_USED(mtr); ut_a(dict_index_is_clust(cursor->index)); ut_ad(dict_index_is_unique(cursor->index)); /* NOTE: For unique non-clustered indexes there may be any number of delete marked records with the same value for the non-clustered index key (remember multiversioning), and which differ only in the row refererence part of the index record, containing the clustered index key fields. For such a secondary index record, to avoid race condition, we must FIRST do the insertion and after that check that the uniqueness condition is not breached! */ /* NOTE: A problem is that in the B-tree node pointers on an upper level may match more to the entry than the actual existing user records on the leaf level. So, even if low_match would suggest that a duplicate key violation may occur, this may not be the case. */ n_unique = dict_index_get_n_unique(cursor->index); if (cursor->low_match >= n_unique) { rec = btr_cur_get_rec(cursor); if (!page_rec_is_infimum(rec)) { offsets = rec_get_offsets(rec, cursor->index, offsets, ULINT_UNDEFINED, &heap); /* We set a lock on the possible duplicate: this is needed in logical logging of MySQL to make sure that in roll-forward we get the same duplicate errors as in original execution */ if (trx->duplicates & TRX_DUP_IGNORE) { /* If the SQL-query will update or replace duplicate key we will take X-lock for duplicates ( REPLACE, LOAD DATAFILE REPLACE, INSERT ON DUPLICATE KEY UPDATE). */ err = row_ins_set_exclusive_rec_lock( LOCK_REC_NOT_GAP, btr_cur_get_block(cursor), rec, cursor->index, offsets, thr); } else { err = row_ins_set_shared_rec_lock( LOCK_REC_NOT_GAP, btr_cur_get_block(cursor), rec, cursor->index, offsets, thr); } if (err != DB_SUCCESS) { goto func_exit; } if (row_ins_dupl_error_with_rec( rec, entry, cursor->index, offsets)) { trx->error_info = cursor->index; err = DB_DUPLICATE_KEY; goto func_exit; } } } if (cursor->up_match >= n_unique) { rec = page_rec_get_next(btr_cur_get_rec(cursor)); if (!page_rec_is_supremum(rec)) { offsets = rec_get_offsets(rec, cursor->index, offsets, ULINT_UNDEFINED, &heap); if (trx->duplicates & TRX_DUP_IGNORE) { /* If the SQL-query will update or replace duplicate key we will take X-lock for duplicates ( REPLACE, LOAD DATAFILE REPLACE, INSERT ON DUPLICATE KEY UPDATE). */ err = row_ins_set_exclusive_rec_lock( LOCK_REC_NOT_GAP, btr_cur_get_block(cursor), rec, cursor->index, offsets, thr); } else { err = row_ins_set_shared_rec_lock( LOCK_REC_NOT_GAP, btr_cur_get_block(cursor), rec, cursor->index, offsets, thr); } if (err != DB_SUCCESS) { goto func_exit; } if (row_ins_dupl_error_with_rec( rec, entry, cursor->index, offsets)) { trx->error_info = cursor->index; err = DB_DUPLICATE_KEY; goto func_exit; } } ut_a(!dict_index_is_clust(cursor->index)); /* This should never happen */ } err = DB_SUCCESS; func_exit: if (UNIV_LIKELY_NULL(heap)) { mem_heap_free(heap); } return(err); } /***************************************************************//** Checks if an index entry has long enough common prefix with an existing record so that the intended insert of the entry must be changed to a modify of the existing record. In the case of a clustered index, the prefix must be n_unique fields long, and in the case of a secondary index, all fields must be equal. @return 0 if no update, ROW_INS_PREV if previous should be updated; currently we do the search so that only the low_match record can match enough to the search tuple, not the next record */ UNIV_INLINE ulint row_ins_must_modify( /*================*/ btr_cur_t* cursor) /*!< in: B-tree cursor */ { ulint enough_match; rec_t* rec; /* NOTE: (compare to the note in row_ins_duplicate_error) Because node pointers on upper levels of the B-tree may match more to entry than to actual user records on the leaf level, we have to check if the candidate record is actually a user record. In a clustered index node pointers contain index->n_unique first fields, and in the case of a secondary index, all fields of the index. */ enough_match = dict_index_get_n_unique_in_tree(cursor->index); if (cursor->low_match >= enough_match) { rec = btr_cur_get_rec(cursor); if (!page_rec_is_infimum(rec)) { return(ROW_INS_PREV); } } return(0); } /***************************************************************//** Tries to insert an index entry to an index. If the index is clustered and a record with the same unique key is found, the other record is necessarily marked deleted by a committed transaction, or a unique key violation error occurs. The delete marked record is then updated to an existing record, and we must write an undo log record on the delete marked record. If the index is secondary, and a record with exactly the same fields is found, the other record is necessarily marked deleted. It is then unmarked. Otherwise, the entry is just inserted to the index. @return DB_SUCCESS, DB_LOCK_WAIT, DB_FAIL if pessimistic retry needed, or error code */ static ulint row_ins_index_entry_low( /*====================*/ ulint mode, /*!< in: BTR_MODIFY_LEAF or BTR_MODIFY_TREE, depending on whether we wish optimistic or pessimistic descent down the index tree */ dict_index_t* index, /*!< in: index */ dtuple_t* entry, /*!< in: index entry to insert */ ulint n_ext, /*!< in: number of externally stored columns */ que_thr_t* thr) /*!< in: query thread */ { btr_cur_t cursor; ulint ignore_sec_unique = 0; ulint modify = 0; /* remove warning */ rec_t* insert_rec; rec_t* rec; ulint err; ulint n_unique; big_rec_t* big_rec = NULL; mtr_t mtr; mem_heap_t* heap = NULL; log_free_check(); mtr_start(&mtr); cursor.thr = thr; /* Note that we use PAGE_CUR_LE as the search mode, because then the function will return in both low_match and up_match of the cursor sensible values */ if (!(thr_get_trx(thr)->check_unique_secondary)) { ignore_sec_unique = BTR_IGNORE_SEC_UNIQUE; } btr_cur_search_to_nth_level(index, 0, entry, PAGE_CUR_LE, mode | BTR_INSERT | ignore_sec_unique, &cursor, 0, &mtr); if (cursor.flag == BTR_CUR_INSERT_TO_IBUF) { /* The insertion was made to the insert buffer already during the search: we are done */ err = DB_SUCCESS; goto function_exit; } #ifdef UNIV_DEBUG { page_t* page = btr_cur_get_page(&cursor); rec_t* first_rec = page_rec_get_next( page_get_infimum_rec(page)); ut_ad(page_rec_is_supremum(first_rec) || rec_get_n_fields(first_rec, index) == dtuple_get_n_fields(entry)); } #endif n_unique = dict_index_get_n_unique(index); if (dict_index_is_unique(index) && (cursor.up_match >= n_unique || cursor.low_match >= n_unique)) { if (dict_index_is_clust(index)) { /* Note that the following may return also DB_LOCK_WAIT */ err = row_ins_duplicate_error_in_clust( &cursor, entry, thr, &mtr); if (err != DB_SUCCESS) { goto function_exit; } } else { mtr_commit(&mtr); err = row_ins_scan_sec_index_for_duplicate( index, entry, thr); mtr_start(&mtr); if (err != DB_SUCCESS) { goto function_exit; } /* We did not find a duplicate and we have now locked with s-locks the necessary records to prevent any insertion of a duplicate by another transaction. Let us now reposition the cursor and continue the insertion. */ btr_cur_search_to_nth_level(index, 0, entry, PAGE_CUR_LE, mode | BTR_INSERT, &cursor, 0, &mtr); } } modify = row_ins_must_modify(&cursor); if (modify != 0) { /* There is already an index entry with a long enough common prefix, we must convert the insert into a modify of an existing record */ if (modify == ROW_INS_NEXT) { rec = page_rec_get_next(btr_cur_get_rec(&cursor)); btr_cur_position(index, rec, btr_cur_get_block(&cursor),&cursor); } if (dict_index_is_clust(index)) { err = row_ins_clust_index_entry_by_modify( mode, &cursor, &heap, &big_rec, entry, thr, &mtr); } else { ut_ad(!n_ext); err = row_ins_sec_index_entry_by_modify( mode, &cursor, entry, thr, &mtr); } } else { if (mode == BTR_MODIFY_LEAF) { err = btr_cur_optimistic_insert( 0, &cursor, entry, &insert_rec, &big_rec, n_ext, thr, &mtr); } else { ut_a(mode == BTR_MODIFY_TREE); if (buf_LRU_buf_pool_running_out()) { err = DB_LOCK_TABLE_FULL; goto function_exit; } err = btr_cur_pessimistic_insert( 0, &cursor, entry, &insert_rec, &big_rec, n_ext, thr, &mtr); } } function_exit: mtr_commit(&mtr); if (UNIV_LIKELY_NULL(big_rec)) { rec_t* rec; ulint* offsets; mtr_start(&mtr); btr_cur_search_to_nth_level(index, 0, entry, PAGE_CUR_LE, BTR_MODIFY_TREE, &cursor, 0, &mtr); rec = btr_cur_get_rec(&cursor); offsets = rec_get_offsets(rec, index, NULL, ULINT_UNDEFINED, &heap); err = btr_store_big_rec_extern_fields( index, btr_cur_get_block(&cursor), rec, offsets, big_rec, &mtr); if (modify) { dtuple_big_rec_free(big_rec); } else { dtuple_convert_back_big_rec(index, entry, big_rec); } mtr_commit(&mtr); } if (UNIV_LIKELY_NULL(heap)) { mem_heap_free(heap); } return(err); } /***************************************************************//** Inserts an index entry to index. Tries first optimistic, then pessimistic descent down the tree. If the entry matches enough to a delete marked record, performs the insert by updating or delete unmarking the delete marked record. @return DB_SUCCESS, DB_LOCK_WAIT, DB_DUPLICATE_KEY, or some other error code */ UNIV_INTERN ulint row_ins_index_entry( /*================*/ dict_index_t* index, /*!< in: index */ dtuple_t* entry, /*!< in: index entry to insert */ ulint n_ext, /*!< in: number of externally stored columns */ ibool foreign,/*!< in: TRUE=check foreign key constraints */ que_thr_t* thr) /*!< in: query thread */ { ulint err; if (foreign && UT_LIST_GET_FIRST(index->table->foreign_list)) { err = row_ins_check_foreign_constraints(index->table, index, entry, thr); if (err != DB_SUCCESS) { return(err); } } /* Try first optimistic descent to the B-tree */ err = row_ins_index_entry_low(BTR_MODIFY_LEAF, index, entry, n_ext, thr); if (err != DB_FAIL) { return(err); } /* Try then pessimistic descent to the B-tree */ err = row_ins_index_entry_low(BTR_MODIFY_TREE, index, entry, n_ext, thr); return(err); } /***********************************************************//** Sets the values of the dtuple fields in entry from the values of appropriate columns in row. */ static void row_ins_index_entry_set_vals( /*=========================*/ dict_index_t* index, /*!< in: index */ dtuple_t* entry, /*!< in: index entry to make */ const dtuple_t* row) /*!< in: row */ { ulint n_fields; ulint i; ut_ad(entry && row); n_fields = dtuple_get_n_fields(entry); for (i = 0; i < n_fields; i++) { dict_field_t* ind_field; dfield_t* field; const dfield_t* row_field; ulint len; field = dtuple_get_nth_field(entry, i); ind_field = dict_index_get_nth_field(index, i); row_field = dtuple_get_nth_field(row, ind_field->col->ind); len = dfield_get_len(row_field); /* Check column prefix indexes */ if (ind_field->prefix_len > 0 && dfield_get_len(row_field) != UNIV_SQL_NULL) { const dict_col_t* col = dict_field_get_col(ind_field); len = dtype_get_at_most_n_mbchars( col->prtype, col->mbminlen, col->mbmaxlen, ind_field->prefix_len, len, dfield_get_data(row_field)); ut_ad(!dfield_is_ext(row_field)); } dfield_set_data(field, dfield_get_data(row_field), len); if (dfield_is_ext(row_field)) { ut_ad(dict_index_is_clust(index)); dfield_set_ext(field); } } } /***********************************************************//** Inserts a single index entry to the table. @return DB_SUCCESS if operation successfully completed, else error code or DB_LOCK_WAIT */ static ulint row_ins_index_entry_step( /*=====================*/ ins_node_t* node, /*!< in: row insert node */ que_thr_t* thr) /*!< in: query thread */ { ulint err; ut_ad(dtuple_check_typed(node->row)); row_ins_index_entry_set_vals(node->index, node->entry, node->row); ut_ad(dtuple_check_typed(node->entry)); err = row_ins_index_entry(node->index, node->entry, 0, TRUE, thr); return(err); } /***********************************************************//** Allocates a row id for row and inits the node->index field. */ UNIV_INLINE void row_ins_alloc_row_id_step( /*======================*/ ins_node_t* node) /*!< in: row insert node */ { dulint row_id; ut_ad(node->state == INS_NODE_ALLOC_ROW_ID); if (dict_index_is_unique(dict_table_get_first_index(node->table))) { /* No row id is stored if the clustered index is unique */ return; } /* Fill in row id value to row */ row_id = dict_sys_get_new_row_id(); dict_sys_write_row_id(node->row_id_buf, row_id); } /***********************************************************//** Gets a row to insert from the values list. */ UNIV_INLINE void row_ins_get_row_from_values( /*========================*/ ins_node_t* node) /*!< in: row insert node */ { que_node_t* list_node; dfield_t* dfield; dtuple_t* row; ulint i; /* The field values are copied in the buffers of the select node and it is safe to use them until we fetch from select again: therefore we can just copy the pointers */ row = node->row; i = 0; list_node = node->values_list; while (list_node) { eval_exp(list_node); dfield = dtuple_get_nth_field(row, i); dfield_copy_data(dfield, que_node_get_val(list_node)); i++; list_node = que_node_get_next(list_node); } } /***********************************************************//** Gets a row to insert from the select list. */ UNIV_INLINE void row_ins_get_row_from_select( /*========================*/ ins_node_t* node) /*!< in: row insert node */ { que_node_t* list_node; dfield_t* dfield; dtuple_t* row; ulint i; /* The field values are copied in the buffers of the select node and it is safe to use them until we fetch from select again: therefore we can just copy the pointers */ row = node->row; i = 0; list_node = node->select->select_list; while (list_node) { dfield = dtuple_get_nth_field(row, i); dfield_copy_data(dfield, que_node_get_val(list_node)); i++; list_node = que_node_get_next(list_node); } } /***********************************************************//** Inserts a row to a table. @return DB_SUCCESS if operation successfully completed, else error code or DB_LOCK_WAIT */ static ulint row_ins( /*====*/ ins_node_t* node, /*!< in: row insert node */ que_thr_t* thr) /*!< in: query thread */ { ulint err; ut_ad(node && thr); if (node->state == INS_NODE_ALLOC_ROW_ID) { row_ins_alloc_row_id_step(node); node->index = dict_table_get_first_index(node->table); node->entry = UT_LIST_GET_FIRST(node->entry_list); if (node->ins_type == INS_SEARCHED) { row_ins_get_row_from_select(node); } else if (node->ins_type == INS_VALUES) { row_ins_get_row_from_values(node); } node->state = INS_NODE_INSERT_ENTRIES; } ut_ad(node->state == INS_NODE_INSERT_ENTRIES); while (node->index != NULL) { err = row_ins_index_entry_step(node, thr); if (err != DB_SUCCESS) { return(err); } node->index = dict_table_get_next_index(node->index); node->entry = UT_LIST_GET_NEXT(tuple_list, node->entry); } ut_ad(node->entry == NULL); node->state = INS_NODE_ALLOC_ROW_ID; return(DB_SUCCESS); } /***********************************************************//** Inserts a row to a table. This is a high-level function used in SQL execution graphs. @return query thread to run next or NULL */ UNIV_INTERN que_thr_t* row_ins_step( /*=========*/ que_thr_t* thr) /*!< in: query thread */ { ins_node_t* node; que_node_t* parent; sel_node_t* sel_node; trx_t* trx; ulint err; ut_ad(thr); trx = thr_get_trx(thr); trx_start_if_not_started(trx); node = thr->run_node; ut_ad(que_node_get_type(node) == QUE_NODE_INSERT); parent = que_node_get_parent(node); sel_node = node->select; if (thr->prev_node == parent) { node->state = INS_NODE_SET_IX_LOCK; } /* If this is the first time this node is executed (or when execution resumes after wait for the table IX lock), set an IX lock on the table and reset the possible select node. MySQL's partitioned table code may also call an insert within the same SQL statement AFTER it has used this table handle to do a search. This happens, for example, when a row update moves it to another partition. In that case, we have already set the IX lock on the table during the search operation, and there is no need to set it again here. But we must write trx->id to node->trx_id_buf. */ trx_write_trx_id(node->trx_id_buf, trx->id); if (node->state == INS_NODE_SET_IX_LOCK) { /* It may be that the current session has not yet started its transaction, or it has been committed: */ if (UT_DULINT_EQ(trx->id, node->trx_id)) { /* No need to do IX-locking */ goto same_trx; } err = lock_table(0, node->table, LOCK_IX, thr); if (err != DB_SUCCESS) { goto error_handling; } node->trx_id = trx->id; same_trx: node->state = INS_NODE_ALLOC_ROW_ID; if (node->ins_type == INS_SEARCHED) { /* Reset the cursor */ sel_node->state = SEL_NODE_OPEN; /* Fetch a row to insert */ thr->run_node = sel_node; return(thr); } } if ((node->ins_type == INS_SEARCHED) && (sel_node->state != SEL_NODE_FETCH)) { ut_ad(sel_node->state == SEL_NODE_NO_MORE_ROWS); /* No more rows to insert */ thr->run_node = parent; return(thr); } /* DO THE CHECKS OF THE CONSISTENCY CONSTRAINTS HERE */ err = row_ins(node, thr); error_handling: trx->error_state = err; if (err != DB_SUCCESS) { /* err == DB_LOCK_WAIT or SQL error detected */ return(NULL); } /* DO THE TRIGGER ACTIONS HERE */ if (node->ins_type == INS_SEARCHED) { /* Fetch a row to insert */ thr->run_node = sel_node; } else { thr->run_node = que_node_get_parent(node); } return(thr); }