Hi, Vicentiu! Just one minor change, see the comment in get_actual_table_name(). After that please push. Well done, thanks! Regards, Sergei On Mar 19, vicentiu@mariadb.org wrote:

revision-id: 135d926d347443672626f1e655709fd5bf6dec80 parent(s): 197afb413fcc9f06b5e5e6ef41ce980d108b354f committer: Vicențiu Ciorbaru branch nick: server timestamp: 2015-03-19 15:16:22 +0200 message:

MDEV-6714 mysqldump slow with tables in big databases

mysqldump now attempts to make use of the INFORMATION_SCHEMA tables. If the table name is not found with a case sensitive search, it fallbacks to a case insensitive search.

--- client/mysqldump.c | 90 ++++++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 71 insertions(+), 19 deletions(-)

diff --git a/client/mysqldump.c b/client/mysqldump.c index 2da4ce6..c265217 100644 --- a/client/mysqldump.c +++ b/client/mysqldump.c @@ -3341,8 +3341,10 @@ static int dump_triggers_for_table(char *table_name, char *db_name) /* Get list of triggers. */

my_snprintf(query_buff, sizeof(query_buff), - "SHOW TRIGGERS LIKE %s", - quote_for_like(table_name, name_buff)); + "SELECT TRIGGER_NAME FROM INFORMATION_SCHEMA.TRIGGERS " + "WHERE EVENT_OBJECT_SCHEMA = DATABASE() AND " + "EVENT_OBJECT_TABLE = \"%s\"", + table_name);

You still need to quote table_name, it might contain a double quote inside. quote_names() almost does what you need, but you don't need a check for MASK_ANSI_QUOTES. So you might either create a quote_names_helper, again, or simply create a new function for this, it's just a few lines anyway. UPD: There are other similar places in mysqldump where it doesn't quote table names, e.g. in get_table_structure(), for show_fields_stmt query. So, please create a separate bug report for this and then it'll fix everything at once.

if (mysql_query_with_error_report(mysql, &show_triggers_rs, query_buff)) goto done; @@ -4695,29 +4697,37 @@ static my_bool dump_all_views_in_db(char *database)

/* - get_actual_table_name -- executes a SHOW TABLES LIKE '%s' to get the actual - table name from the server for the table name given on the command line. - we do this because the table name given on the command line may be a - different case (e.g. T1 vs t1) - - RETURN - pointer to the table name - 0 if error + See get_actual_table_name. Used to retrieve the correct table name + from the database schema. */ - -static char *get_actual_table_name(const char *old_table_name, MEM_ROOT *root) +static char *get_actual_table_name_helper(const char *old_table_name, + my_bool case_sensitive, + MEM_ROOT *root) { char *name= 0; MYSQL_RES *table_res; MYSQL_ROW row; char query[50 + 2*NAME_LEN]; char show_name_buff[FN_REFLEN]; - DBUG_ENTER("get_actual_table_name"); + DBUG_ENTER("get_actual_table_name_helper");

/* Check memory for quote_for_like() */ DBUG_ASSERT(2*sizeof(old_table_name) < sizeof(show_name_buff)); - my_snprintf(query, sizeof(query), "SHOW TABLES LIKE %s", - quote_for_like(old_table_name, show_name_buff)); + + if (case_sensitive) + { + DBUG_PRINT("info", ("case sensitive search")); + my_snprintf(query, sizeof(query), + "SELECT table_name FROM INFORMATION_SCHEMA.TABLES " + "WHERE table_schema = DATABASE() AND table_name = \"%s\"", + old_table_name); + } + else + { + DBUG_PRINT("info", ("case insensitive search")); + my_snprintf(query, sizeof(query), "SHOW TABLES LIKE %s", + quote_for_like(old_table_name, show_name_buff)); + }

if (mysql_query_with_error_report(mysql, 0, query)) return NullS; @@ -4742,6 +4752,46 @@ static char *get_actual_table_name(const char *old_table_name, MEM_ROOT *root) DBUG_RETURN(name); }

+/* + get_actual_table_name -- executes a SELECT .. FROM I_S.tables to check + if the table name given on the command line matches the one in the database. + If the table is not found, it falls back to a slower SHOW TABLES LIKE '%s' to + get the actual table name from the server. + + We do this because the table name given on the command line may be a + different case (e.g. T1 vs t1), but checking this takes a long time + when there are many tables present. + + RETURN + pointer to the table name + 0 if error +*/ + +static char *get_actual_table_name(const char *old_table_name, MEM_ROOT *root) +{ + char *name= 0; + MYSQL_RES *table_res; + MYSQL_ROW row; + int lower_case_table_names; + const char *show_var_query = "SHOW VARIABLES LIKE 'lower_case_table_names'"; + DBUG_ENTER("get_actual_table_name"); + + if (mysql_query_with_error_report(mysql, &table_res, show_var_query)) + return NullS;

I'd prefer if you do it only once, not for every get_actual_table_name() call.

+ + if ((row= mysql_fetch_row(table_res))) + { + lower_case_table_names= atoi(row[1]); + mysql_free_result(table_res); + } + + name= get_actual_table_name_helper(old_table_name, TRUE, root); + if (!name && !lower_case_table_names) + name= get_actual_table_name_helper(old_table_name, FALSE, root); + DBUG_RETURN(name); +} + +

static int dump_selected_tables(char *db, char **table_names, int tables) {