diff options
| -rw-r--r-- | include/my_global.h | 2 | ||||
| -rw-r--r-- | mysql-test/r/ps_1general.result | 19 | ||||
| -rw-r--r-- | mysql-test/r/query_cache_merge.result | 1 | ||||
| -rw-r--r-- | mysql-test/r/trigger.result | 1 | ||||
| -rw-r--r-- | mysql-test/t/disabled.def | 1 | ||||
| -rw-r--r-- | mysql-test/t/ps_1general.test | 5 | ||||
| -rw-r--r-- | mysql-test/t/query_cache_merge.test | 10 | ||||
| -rw-r--r-- | mysql-test/t/trigger.test | 7 | ||||
| -rw-r--r-- | sql/item.cc | 39 | ||||
| -rw-r--r-- | sql/item.h | 1 | ||||
| -rw-r--r-- | sql/my_decimal.h | 8 | ||||
| -rw-r--r-- | sql/mysql_priv.h | 40 | ||||
| -rw-r--r-- | sql/mysqld.cc | 9 | ||||
| -rw-r--r-- | sql/share/errmsg.txt | 6 | ||||
| -rw-r--r-- | sql/sql_base.cc | 110 | ||||
| -rw-r--r-- | sql/sql_class.cc | 10 | ||||
| -rw-r--r-- | sql/sql_class.h | 86 | ||||
| -rw-r--r-- | sql/sql_parse.cc | 25 | ||||
| -rw-r--r-- | sql/sql_prepare.cc | 516 | ||||
| -rw-r--r-- | sql/table.h | 130 | ||||
| -rw-r--r-- | tests/mysql_client_test.c | 120 |
21 files changed, 1028 insertions, 118 deletions
diff --git a/include/my_global.h b/include/my_global.h index d9a8aeca881..a1118f0cb3d 100644 --- a/include/my_global.h +++ b/include/my_global.h @@ -568,7 +568,7 @@ typedef unsigned short ushort; #define CMP_NUM(a,b) (((a) < (b)) ? -1 : ((a) == (b)) ? 0 : 1) #define sgn(a) (((a) < 0) ? -1 : ((a) > 0) ? 1 : 0) -#define swap_variables(t, a, b) { register t dummy; dummy= a; a= b; b= dummy; } +#define swap_variables(t, a, b) { t dummy; dummy= a; a= b; b= dummy; } #define test(a) ((a) ? 1 : 0) #define set_if_bigger(a,b) do { if ((a) < (b)) (a)=(b); } while(0) #define set_if_smaller(a,b) do { if ((a) > (b)) (a)=(b); } while(0) diff --git a/mysql-test/r/ps_1general.result b/mysql-test/r/ps_1general.result index 1c5f0e4dfd6..33849eefe7a 100644 --- a/mysql-test/r/ps_1general.result +++ b/mysql-test/r/ps_1general.result @@ -143,32 +143,32 @@ b char(30) ); insert into t5( a, b, c) values( 9, 'recreated table', 9); execute stmt2 ; -a b c -9 recreated table 9 +a c b +9 9 recreated table drop table t5 ; create table t5 ( a int primary key, b char(30), c int, -d timestamp default current_timestamp +d timestamp default '2008-02-23 09:23:45' ); insert into t5( a, b, c) values( 9, 'recreated table', 9); execute stmt2 ; -a b c -9 recreated table 9 +a b c d +9 recreated table 9 2008-02-23 09:23:45 drop table t5 ; create table t5 ( a int primary key, -d timestamp default current_timestamp, +d timestamp default '2008-02-23 09:23:45', b char(30), c int ); insert into t5( a, b, c) values( 9, 'recreated table', 9); execute stmt2 ; -a b c -9 recreated table 9 +a d b c +9 2008-02-23 09:23:45 recreated table 9 drop table t5 ; create table t5 ( @@ -189,7 +189,8 @@ f3 int ); insert into t5( f1, f2, f3) values( 9, 'recreated table', 9); execute stmt2 ; -ERROR 42S22: Unknown column 'test.t5.a' in 'field list' +f1 f2 f3 +9 recreated table 9 drop table t5 ; prepare stmt1 from ' select * from t1 where a <= 2 ' ; execute stmt1 ; diff --git a/mysql-test/r/query_cache_merge.result b/mysql-test/r/query_cache_merge.result index c6df4266de2..d2bbe217815 100644 --- a/mysql-test/r/query_cache_merge.result +++ b/mysql-test/r/query_cache_merge.result @@ -18,3 +18,4 @@ Variable_name Value Qcache_queries_in_cache 0 drop table t1,t2,t3,t4,t5,t6,t7,t8,t9,t10,t11,t12,t13,t14,t15,t16,t17,t18,t19,t20,t21,t22,t23,t24,t25,t26,t27,t28,t29,t30,t31,t32,t33,t34,t35,t36,t37,t38,t39,t40,t41,t42,t43,t44,t45,t46,t47,t48,t49,t50,t51,t52,t53,t54,t55,t56,t57,t58,t59,t60,t61,t62,t63,t64,t65,t66,t67,t68,t69,t70,t71,t72,t73,t74,t75,t76,t77,t78,t79,t80,t81,t82,t83,t84,t85,t86,t87,t88,t89,t90,t91,t92,t93,t94,t95,t96,t97,t98,t99,t100,t101,t102,t103,t104,t105,t106,t107,t108,t109,t110,t111,t112,t113,t114,t115,t116,t117,t118,t119,t120,t121,t122,t123,t124,t125,t126,t127,t128,t129,t130,t131,t132,t133,t134,t135,t136,t137,t138,t139,t140,t141,t142,t143,t144,t145,t146,t147,t148,t149,t150,t151,t152,t153,t154,t155,t156,t157,t158,t159,t160,t161,t162,t163,t164,t165,t166,t167,t168,t169,t170,t171,t172,t173,t174,t175,t176,t177,t178,t179,t180,t181,t182,t183,t184,t185,t186,t187,t188,t189,t190,t191,t192,t193,t194,t195,t196,t197,t198,t199,t200,t201,t202,t203,t204,t205,t206,t207,t208,t209,t210,t211,t212,t213,t214,t215,t216,t217,t218,t219,t220,t221,t222,t223,t224,t225,t226,t227,t228,t229,t230,t231,t232,t233,t234,t235,t236,t237,t238,t239,t240,t241,t242,t243,t244,t245,t246,t247,t248,t249,t250,t251,t252,t253,t254,t255,t256,t257,t00; SET @@global.query_cache_size=0; +set @@global.table_definition_cache=@save_table_definition_cache; diff --git a/mysql-test/r/trigger.result b/mysql-test/r/trigger.result index e7f5c41513b..35d5134fa6b 100644 --- a/mysql-test/r/trigger.result +++ b/mysql-test/r/trigger.result @@ -820,7 +820,6 @@ call p1(); drop trigger t1_bi; create trigger t1_bi after insert on t1 for each row insert into t3 values (new.id); execute stmt1; -ERROR 42S02: Table 'test.t3' doesn't exist call p1(); ERROR 42S02: Table 'test.t3' doesn't exist deallocate prepare stmt1; diff --git a/mysql-test/t/disabled.def b/mysql-test/t/disabled.def index af7b9c25f18..24a5522b3dc 100644 --- a/mysql-test/t/disabled.def +++ b/mysql-test/t/disabled.def @@ -18,6 +18,5 @@ federated_transactions : Bug#29523 Transactions do not work lowercase_table3 : Bug#32667 lowercase_table3.test reports to error log ctype_create : Bug#32965 main.ctype_create fails status : Bug#32966 main.status fails -ps_ddl : Bug#12093 2007-12-14 pending WL#4165 / WL#4166 csv_alter_table : Bug#33696 2008-01-21 pcrews no .result file - bug allows NULL columns in CSV tables cast : Bug#35594 2008-03-27 main.cast fails on Windows2003-64 diff --git a/mysql-test/t/ps_1general.test b/mysql-test/t/ps_1general.test index 42bf39890de..95cbd908933 100644 --- a/mysql-test/t/ps_1general.test +++ b/mysql-test/t/ps_1general.test @@ -181,7 +181,7 @@ create table t5 a int primary key, b char(30), c int, - d timestamp default current_timestamp + d timestamp default '2008-02-23 09:23:45' ); insert into t5( a, b, c) values( 9, 'recreated table', 9); execute stmt2 ; @@ -191,7 +191,7 @@ drop table t5 ; create table t5 ( a int primary key, - d timestamp default current_timestamp, + d timestamp default '2008-02-23 09:23:45', b char(30), c int ); @@ -218,7 +218,6 @@ create table t5 f3 int ); insert into t5( f1, f2, f3) values( 9, 'recreated table', 9); ---error 1054 execute stmt2 ; drop table t5 ; diff --git a/mysql-test/t/query_cache_merge.test b/mysql-test/t/query_cache_merge.test index 36b8662f088..5247d29a83c 100644 --- a/mysql-test/t/query_cache_merge.test +++ b/mysql-test/t/query_cache_merge.test @@ -25,6 +25,15 @@ while ($1) } --enable_warnings +# +# In order for the test to pass in --ps-protocol, we must +# set table_definition_cache size to at least 258 elements. +# Otherwise table versions are bound to change between +# prepare and execute, and we will get a constant validation +# error. See WL#4165 for details. +# +set @save_table_definition_cache= @@global.table_definition_cache; +set @@global.table_definition_cache=512; create table t00 (a int) engine=MERGE UNION=(t1,t2,t3,t4,t5,t6,t7,t8,t9,t10,t11,t12,t13,t14,t15,t16,t17,t18,t19,t20,t21,t22,t23,t24,t25,t26,t27,t28,t29,t30,t31,t32,t33,t34,t35,t36,t37,t38,t39,t40,t41,t42,t43,t44,t45,t46,t47,t48,t49,t50,t51,t52,t53,t54,t55,t56,t57,t58,t59,t60,t61,t62,t63,t64,t65,t66,t67,t68,t69,t70,t71,t72,t73,t74,t75,t76,t77,t78,t79,t80,t81,t82,t83,t84,t85,t86,t87,t88,t89,t90,t91,t92,t93,t94,t95,t96,t97,t98,t99,t100,t101,t102,t103,t104,t105,t106,t107,t108,t109,t110,t111,t112,t113,t114,t115,t116,t117,t118,t119,t120,t121,t122,t123,t124,t125,t126,t127,t128,t129,t130,t131,t132,t133,t134,t135,t136,t137,t138,t139,t140,t141,t142,t143,t144,t145,t146,t147,t148,t149,t150,t151,t152,t153,t154,t155,t156,t157,t158,t159,t160,t161,t162,t163,t164,t165,t166,t167,t168,t169,t170,t171,t172,t173,t174,t175,t176,t177,t178,t179,t180,t181,t182,t183,t184,t185,t186,t187,t188,t189,t190,t191,t192,t193,t194,t195,t196,t197,t198,t199,t200,t201,t202,t203,t204,t205,t206,t207,t208,t209,t210,t211,t212,t213,t214,t215,t216,t217,t218,t219,t220,t221,t222,t223,t224,t225,t226,t227,t228,t229,t230,t231,t232,t233,t234,t235,t236,t237,t238,t239,t240,t241,t242,t243,t244,t245,t246,t247,t248,t249,t250,t251,t252,t253,t254,t255,t256,t257) INSERT_METHOD=FIRST; enable_query_log; select count(*) from t00; @@ -36,5 +45,6 @@ show status like "Qcache_queries_in_cache"; drop table t1,t2,t3,t4,t5,t6,t7,t8,t9,t10,t11,t12,t13,t14,t15,t16,t17,t18,t19,t20,t21,t22,t23,t24,t25,t26,t27,t28,t29,t30,t31,t32,t33,t34,t35,t36,t37,t38,t39,t40,t41,t42,t43,t44,t45,t46,t47,t48,t49,t50,t51,t52,t53,t54,t55,t56,t57,t58,t59,t60,t61,t62,t63,t64,t65,t66,t67,t68,t69,t70,t71,t72,t73,t74,t75,t76,t77,t78,t79,t80,t81,t82,t83,t84,t85,t86,t87,t88,t89,t90,t91,t92,t93,t94,t95,t96,t97,t98,t99,t100,t101,t102,t103,t104,t105,t106,t107,t108,t109,t110,t111,t112,t113,t114,t115,t116,t117,t118,t119,t120,t121,t122,t123,t124,t125,t126,t127,t128,t129,t130,t131,t132,t133,t134,t135,t136,t137,t138,t139,t140,t141,t142,t143,t144,t145,t146,t147,t148,t149,t150,t151,t152,t153,t154,t155,t156,t157,t158,t159,t160,t161,t162,t163,t164,t165,t166,t167,t168,t169,t170,t171,t172,t173,t174,t175,t176,t177,t178,t179,t180,t181,t182,t183,t184,t185,t186,t187,t188,t189,t190,t191,t192,t193,t194,t195,t196,t197,t198,t199,t200,t201,t202,t203,t204,t205,t206,t207,t208,t209,t210,t211,t212,t213,t214,t215,t216,t217,t218,t219,t220,t221,t222,t223,t224,t225,t226,t227,t228,t229,t230,t231,t232,t233,t234,t235,t236,t237,t238,t239,t240,t241,t242,t243,t244,t245,t246,t247,t248,t249,t250,t251,t252,t253,t254,t255,t256,t257,t00; SET @@global.query_cache_size=0; +set @@global.table_definition_cache=@save_table_definition_cache; # End of 4.1 tests diff --git a/mysql-test/t/trigger.test b/mysql-test/t/trigger.test index 921c9579bfb..c57178c1928 100644 --- a/mysql-test/t/trigger.test +++ b/mysql-test/t/trigger.test @@ -997,11 +997,10 @@ call p1(); # Altering trigger forcing it use different set of tables drop trigger t1_bi; create trigger t1_bi after insert on t1 for each row insert into t3 values (new.id); -# Until we implement proper mechanism for invalidation of PS/SP when table -# or SP's are changed these two statements will fail with 'Table ... was -# not locked' error (this mechanism should be based on the new TDC). ---error ER_NO_SUCH_TABLE execute stmt1; +# Until we implement proper mechanism for invalidation of SP statements +# invoked whenever a table used in SP changes, this statement will fail with +# 'Table ... does not exist' error. --error ER_NO_SUCH_TABLE call p1(); deallocate prepare stmt1; diff --git a/sql/item.cc b/sql/item.cc index 883c293f645..04c75107d14 100644 --- a/sql/item.cc +++ b/sql/item.cc @@ -3161,6 +3161,45 @@ void Item_param::print(String *str, enum_query_type query_type) } +/** + Preserve the original parameter types and values + when re-preparing a prepared statement. + + Copy parameter type information and conversion function + pointers from a parameter of the old statement to the + corresponding parameter of the new one. + + Move parameter values from the old parameters to the new + one. We simply "exchange" the values, which allows + to save on allocation and character set conversion in + case a parameter is a string or a blob/clob. + + @param[in] src parameter item of the original + prepared statement +*/ + +void +Item_param::set_param_type_and_swap_value(Item_param *src) +{ + unsigned_flag= src->unsigned_flag; + param_type= src->param_type; + set_param_func= src->set_param_func; + item_type= src->item_type; + item_result_type= src->item_result_type; + + collation.set(src->collation.collation); + maybe_null= src->maybe_null; + null_value= src->null_value; + max_length= src->max_length; + decimals= src->decimals; + state= src->state; + value= src->value; + + decimal_value.swap(src->decimal_value); + str_value.swap(src->str_value); + str_value_ptr.swap(src->str_value_ptr); +} + /**************************************************************************** Item_copy_string ****************************************************************************/ diff --git a/sql/item.h b/sql/item.h index cd8bb4faccb..465d6f4d54c 100644 --- a/sql/item.h +++ b/sql/item.h @@ -1684,6 +1684,7 @@ public: bool eq(const Item *item, bool binary_cmp) const; /** Item is a argument to a limit clause. */ bool limit_clause_param; + void set_param_type_and_swap_value(Item_param *from); }; diff --git a/sql/my_decimal.h b/sql/my_decimal.h index 1885036f42b..b096abaf8ae 100644 --- a/sql/my_decimal.h +++ b/sql/my_decimal.h @@ -114,6 +114,14 @@ public: bool sign() const { return decimal_t::sign; } void sign(bool s) { decimal_t::sign= s; } uint precision() const { return intg + frac; } + + /** Swap two my_decimal values */ + void swap(my_decimal &rhs) + { + swap_variables(my_decimal, *this, rhs); + /* Swap the buffer pointers back */ + swap_variables(decimal_digit_t *, buf, rhs.buf); + } }; diff --git a/sql/mysql_priv.h b/sql/mysql_priv.h index 26f253a6f8e..491a4c8ca1b 100644 --- a/sql/mysql_priv.h +++ b/sql/mysql_priv.h @@ -259,6 +259,21 @@ protected: #define USER_VARS_HASH_SIZE 16 #define TABLE_OPEN_CACHE_MIN 64 #define TABLE_OPEN_CACHE_DEFAULT 64 +#define TABLE_DEF_CACHE_DEFAULT 256 +/** + We must have room for at least 256 table definitions in the table + cache, since otherwise there is no chance prepared + statements that use these many tables can work. + Prepared statements use table definition cache ids (table_map_id) + as table version identifiers. If the table definition + cache size is less than the number of tables used in a statement, + the contents of the table definition cache is guaranteed to rotate + between a prepare and execute. This leads to stable validation + errors. In future we shall use more stable version identifiers, + for now the only solution is to ensure that the table definition + cache can contain at least all tables of a given statement. +*/ +#define TABLE_DEF_CACHE_MIN 256 /* Value of 9236 discovered through binary search 2006-09-26 on Ubuntu Dapper @@ -670,6 +685,31 @@ const char *set_thd_proc_info(THD *thd, const char *info, const char *calling_file, const unsigned int calling_line); +/** + Enumerate possible types of a table from re-execution + standpoint. + TABLE_LIST class has a member of this type. + At prepared statement prepare, this member is assigned a value + as of the current state of the database. Before (re-)execution + of a prepared statement, we check that the value recorded at + prepare matches the type of the object we obtained from the + table definition cache. + + @sa check_and_update_metadata_version() + @sa Execute_observer + @sa Prepared_statement::reprepare() +*/ + +enum enum_metadata_type +{ + /** Initial value set by the parser */ + METADATA_NULL= 0, + METADATA_VIEW, + METADATA_BASE_TABLE, + METADATA_I_S_TABLE, + METADATA_TMP_TABLE +}; + /* External variables */ diff --git a/sql/mysqld.cc b/sql/mysqld.cc index 36a5b1a10d9..d93100a068f 100644 --- a/sql/mysqld.cc +++ b/sql/mysqld.cc @@ -3089,6 +3089,7 @@ SHOW_VAR com_status_vars[]= { {"stmt_execute", (char*) offsetof(STATUS_VAR, com_stmt_execute), SHOW_LONG_STATUS}, {"stmt_fetch", (char*) offsetof(STATUS_VAR, com_stmt_fetch), SHOW_LONG_STATUS}, {"stmt_prepare", (char*) offsetof(STATUS_VAR, com_stmt_prepare), SHOW_LONG_STATUS}, + {"stmt_reprepare", (char*) offsetof(STATUS_VAR, com_stmt_reprepare), SHOW_LONG_STATUS}, {"stmt_reset", (char*) offsetof(STATUS_VAR, com_stmt_reset), SHOW_LONG_STATUS}, {"stmt_send_long_data", (char*) offsetof(STATUS_VAR, com_stmt_send_long_data), SHOW_LONG_STATUS}, {"truncate", (char*) offsetof(STATUS_VAR, com_stat[(uint) SQLCOM_TRUNCATE]), SHOW_LONG_STATUS}, @@ -3177,7 +3178,7 @@ static int init_common_variables(const char *conf_file_name, int argc, We have few debug-only commands in com_status_vars, only visible in debug builds. for simplicity we enable the assert only in debug builds - There are 7 Com_ variables which don't have corresponding SQLCOM_ values: + There are 8 Com_ variables which don't have corresponding SQLCOM_ values: (TODO strictly speaking they shouldn't be here, should not have Com_ prefix that is. Perhaps Stmt_ ? Comstmt_ ? Prepstmt_ ?) @@ -3186,6 +3187,7 @@ static int init_common_variables(const char *conf_file_name, int argc, Com_stmt_execute => com_stmt_execute Com_stmt_fetch => com_stmt_fetch Com_stmt_prepare => com_stmt_prepare + Com_stmt_reprepare => com_stmt_reprepare Com_stmt_reset => com_stmt_reset Com_stmt_send_long_data => com_stmt_send_long_data @@ -3194,7 +3196,7 @@ static int init_common_variables(const char *conf_file_name, int argc, of SQLCOM_ constants. */ compile_time_assert(sizeof(com_status_vars)/sizeof(com_status_vars[0]) - 1 == - SQLCOM_END + 7); + SQLCOM_END + 8); #endif load_defaults(conf_file_name, groups, &argc, &argv); @@ -6757,7 +6759,8 @@ The minimum value for this variable is 4096.", {"table_definition_cache", OPT_TABLE_DEF_CACHE, "The number of cached table definitions.", (uchar**) &table_def_size, (uchar**) &table_def_size, - 0, GET_ULONG, REQUIRED_ARG, 128, 1, 512*1024L, 0, 1, 0}, + 0, GET_ULONG, REQUIRED_ARG, TABLE_DEF_CACHE_DEFAULT, TABLE_DEF_CACHE_MIN, + 512*1024L, 0, 1, 0}, {"table_open_cache", OPT_TABLE_OPEN_CACHE, "The number of cached open tables.", (uchar**) &table_cache_size, (uchar**) &table_cache_size, 0, GET_ULONG, diff --git a/sql/share/errmsg.txt b/sql/share/errmsg.txt index 7990baa6bb7..684d1ce9421 100644 --- a/sql/share/errmsg.txt +++ b/sql/share/errmsg.txt @@ -6120,3 +6120,9 @@ ER_NO_FORMAT_DESCRIPTION_EVENT_BEFORE_BINLOG_STATEMENT eng "The BINLOG statement of type `%s` was not preceded by a format description BINLOG statement." ER_SLAVE_CORRUPT_EVENT eng "Corrupted replication event was detected" + +ER_NEED_REPREPARE + eng "Prepared statement needs to be re-prepared" + +ER_PS_REBIND + eng "Prepared statement result set has changed, a rebind needed" diff --git a/sql/sql_base.cc b/sql/sql_base.cc index f0faf034027..62a723953ed 100644 --- a/sql/sql_base.cc +++ b/sql/sql_base.cc @@ -3717,6 +3717,72 @@ void assign_new_table_id(TABLE_SHARE *share) DBUG_VOID_RETURN; } + +/** + Compare metadata versions of an element obtained from the table + definition cache and its corresponding node in the parse tree. + + If the new and the old values mismatch, invoke + Metadata_version_observer. + + At prepared statement prepare, all TABLE_LIST version values are + NULL and we always have a mismatch. But there is no observer set + in THD, and therefore no error is reported. Instead, we update + the value in the parse tree, effectively recording the original + version. + At prepared statement execute, an observer may be installed. If + there is a version mismatch, we push an error and return TRUE. + + For conventional execution (no prepared statements), the + observer is never installed. + + @sa Execute_observer + @sa check_prepared_statement() to see cases when an observer is installed + @sa TABLE_LIST::is_metadata_version_equal() + @sa TABLE_SHARE::get_metadata_version() + + @param[in] thd used to report errors + @param[in,out] tables TABLE_LIST instance created by the parser + Metadata version information in this object + is updated upon success. + @param[in] table_share an element from the table definition cache + + @retval TRUE an error, which has been reported + @retval FALSE success, version in TABLE_LIST has been updated +*/ + +bool +check_and_update_table_version(THD *thd, + TABLE_LIST *tables, TABLE_SHARE *table_share) +{ + if (! tables->is_metadata_version_equal(table_share)) + { + if (thd->m_metadata_observer && + thd->m_metadata_observer->check_metadata_change(thd)) + { + /* + Version of the table share is different from the + previous execution of the prepared statement, and it is + unacceptable for this SQLCOM. Error has been reported. + */ + return TRUE; + } + /* Always maintain the latest version */ + tables->set_metadata_version(table_share); + } +#if 0 +#ifndef DBUG_OFF + /* Spuriously reprepare each statement. */ + if (thd->m_metadata_observer && thd->stmt_arena->is_reprepared == FALSE) + { + thd->m_metadata_observer->check_metadata_change(thd); + return TRUE; + } +#endif +#endif + return FALSE; +} + /* Load a table definition from file and open unireg table @@ -3762,6 +3828,8 @@ retry: if (share->is_view) { + if (check_and_update_table_version(thd, table_list, share)) + goto err; if (table_list->i_s_requested_object & OPEN_TABLE_ONLY) goto err; @@ -3779,6 +3847,26 @@ retry: release_table_share(share, RELEASE_NORMAL); DBUG_RETURN((flags & OPEN_VIEW_NO_PARSE)? -1 : 0); } + else if (table_list->view) + { + /* + We're trying to open a table for what was a view. + This can only happen during (re-)execution. + At prepared statement prepare the view has been opened and + merged into the statement parse tree. After that, someone + performed a DDL and replaced the view with a base table. + Don't try to open the table inside a prepared statement, + invalidate it instead. + + Note, the assert below is known to fail inside stored + procedures (Bug#27011). + */ + DBUG_ASSERT(thd->m_metadata_observer); + check_and_update_table_version(thd, table_list, share); + /* Always an error. */ + DBUG_ASSERT(thd->is_error()); + goto err; + } if (table_list->i_s_requested_object & OPEN_VIEW_ONLY) goto err; @@ -4375,8 +4463,18 @@ int open_tables(THD *thd, TABLE_LIST **start, uint *counter, uint flags) */ if (tables->schema_table) { - if (!mysql_schema_table(thd, thd->lex, tables)) + /* + If this information_schema table is merged into a mergeable + view, ignore it for now -- it will be filled when its respective + TABLE_LIST is processed. This code works only during re-execution. + */ + if (tables->view) + goto process_view_routines; + if (!mysql_schema_table(thd, thd->lex, tables) && + !check_and_update_table_version(thd, tables, tables->table->s)) + { continue; + } DBUG_RETURN(-1); } (*counter)++; @@ -4524,6 +4622,12 @@ int open_tables(THD *thd, TABLE_LIST **start, uint *counter, uint flags) } tables->table->grant= tables->grant; + if (check_and_update_table_version(thd, tables, tables->table->s)) + { + result= -1; + goto err; + } + /* Attach MERGE children if not locked already. */ DBUG_PRINT("tcache", ("is parent: %d is child: %d", test(tables->table->child_l), @@ -4582,7 +4686,11 @@ process_view_routines: error happens on a MERGE child, clear the parents TABLE reference. */ if (tables->parent_l) + { + if (tables->parent_l->next_global == tables->parent_l->table->child_l) + tables->parent_l->next_global= *tables->parent_l->table->child_last_l; tables->parent_l->table= NULL; + } tables->table= NULL; } DBUG_PRINT("tcache", ("returning: %d", result)); diff --git a/sql/sql_class.cc b/sql/sql_class.cc index 7c57e3fc40e..6a4ef0781a2 100644 --- a/sql/sql_class.cc +++ b/sql/sql_class.cc @@ -359,6 +359,10 @@ char *thd_security_context(THD *thd, char *buffer, unsigned int length, return thd->strmake(str.ptr(), str.length()); } +Metadata_version_observer::~Metadata_version_observer() +{ +} + /** Clear this diagnostics area. @@ -2767,7 +2771,8 @@ void THD::restore_backup_open_tables_state(Open_tables_state *backup) DBUG_ASSERT(open_tables == 0 && temporary_tables == 0 && handler_tables == 0 && derived_tables == 0 && lock == 0 && locked_tables == 0 && - prelocked_mode == NON_PRELOCKED); + prelocked_mode == NON_PRELOCKED && + m_metadata_observer == NULL); set_open_tables_state(backup); DBUG_VOID_RETURN; } @@ -2871,6 +2876,7 @@ void THD::reset_sub_statement_state(Sub_statement_state *backup, first_successful_insert_id_in_prev_stmt; backup->first_successful_insert_id_in_cur_stmt= first_successful_insert_id_in_cur_stmt; + backup->m_metadata_observer= m_metadata_observer; if ((!lex->requires_prelocking() || is_update_query(lex->sql_command)) && !current_stmt_binlog_row_based) @@ -2890,6 +2896,7 @@ void THD::reset_sub_statement_state(Sub_statement_state *backup, cuted_fields= 0; transaction.savepoints= 0; first_successful_insert_id_in_cur_stmt= 0; + m_metadata_observer= 0; } @@ -2938,6 +2945,7 @@ void THD::restore_sub_statement_state(Sub_statement_state *backup) */ examined_row_count+= backup->examined_row_count; cuted_fields+= backup->cuted_fields; + m_metadata_observer= backup->m_metadata_observer; } diff --git a/sql/sql_class.h b/sql/sql_class.h index 2bfcc43a454..837b74b3b60 100644 --- a/sql/sql_class.h +++ b/sql/sql_class.h @@ -23,6 +23,53 @@ #include "log.h" #include "rpl_tblmap.h" +/** + An abstract interface that can be used to take an action when + the locking module notices that a table version has changed + since the last execution. "Table" here may refer to any kind of + table -- a base table, a temporary table, a view or an + information schema table. + + When we open and lock tables for execution of a prepared + statement, we must verify that they did not change + since statement prepare. If some table did change, the statement + parse tree *may* be no longer valid, e.g. in case it contains + optimizations that depend on table metadata. + + This class provides an abstract interface (a method) that is + invoked when such a situation takes place. + The implementation of the interface in most cases simply + reports an error, but the exact details depend on the nature of + the SQL statement. + + At most 1 instance of this class is active at a time, in which + case THD::m_metadata_observer is not NULL. + + @sa check_and_update_metadata_version() for details of the + version tracking algorithm + + @sa Execute_observer for details of how we detect that + a metadata change is fatal and a re-prepare is necessary + + @sa Open_tables_state::m_metadata_observer for the life cycle + of metadata observers. +*/ + +class Metadata_version_observer +{ +protected: + virtual ~Metadata_version_observer(); +public: + /** + Check if a change of metadata is OK. In future + the signature of this method may be extended to accept the old + and the new versions, but since currently the check is very + simple, we only need the THD to report an error. + */ + virtual bool check_metadata_change(THD *thd)= 0; +}; + + class Relay_log_info; class Query_log_event; @@ -406,6 +453,7 @@ typedef struct system_status_var ulong filesort_scan_count; /* Prepared statements and binary protocol */ ulong com_stmt_prepare; + ulong com_stmt_reprepare; ulong com_stmt_execute; ulong com_stmt_send_long_data; ulong com_stmt_fetch; @@ -436,7 +484,7 @@ void free_tmp_table(THD *thd, TABLE *entry); /* The following macro is to make init of Query_arena simpler */ #ifndef DBUG_OFF -#define INIT_ARENA_DBUG_INFO is_backup_arena= 0 +#define INIT_ARENA_DBUG_INFO is_backup_arena= 0; is_reprepared= FALSE; #else #define INIT_ARENA_DBUG_INFO #endif @@ -452,6 +500,7 @@ public: MEM_ROOT *mem_root; // Pointer to current memroot #ifndef DBUG_OFF bool is_backup_arena; /* True if this arena is used for backup. */ + bool is_reprepared; #endif /* The states relfects three diffrent life cycles for three @@ -789,6 +838,20 @@ class Open_tables_state { public: /** + As part of class THD, this member is set during execution + of a prepared statement. When it is set, it is used + by the locking subsystem to report a change in table metadata. + + When Open_tables_state part of THD is reset to open + a system or INFORMATION_SCHEMA table, the member is cleared + to avoid spurious ER_NEED_REPREPARE errors -- system and + INFORMATION_SCHEMA tables are not subject to metadata version + tracking. + @sa check_and_update_metadata_version() + */ + Metadata_version_observer *m_metadata_observer; + + /** List of regular tables in use by this thread. Contains temporary and base tables that were opened with @see open_tables(). */ @@ -891,6 +954,7 @@ public: extra_lock= lock= locked_tables= 0; prelocked_mode= NON_PRELOCKED; state_flags= 0U; + m_metadata_observer= NULL; } }; @@ -919,6 +983,25 @@ public: bool enable_slow_log; bool last_insert_id_used; SAVEPOINT *savepoints; + /** + When inside a substatement (a stored function or trigger + statement), clear the metadata observer in THD, if any. + Remember the value of the observer here, to be able + to restore it when leaving the substatement. + + We reset the observer to suppress errors when a substatement + uses temporary tables. If a temporary table does not exist + at start of the main statement, it's not prelocked + and thus is not validated with other prelocked tables. + + Later on, when the temporary table is opened, metadata + versions mismatch, expectedly. + + The proper solution for the problem is to re-validate tables + of substatements (Bug#12257, Bug#27011, Bug#32868, Bug#33000), + but it's not implemented yet. + */ + Metadata_version_observer *m_metadata_observer; }; @@ -2777,6 +2860,7 @@ public: #define CF_STATUS_COMMAND 4 #define CF_SHOW_TABLE_COMMAND 8 #define CF_WRITE_LOGS_COMMAND 16 +#define CF_REEXECUTION_FRAGILE 32 /* Functions in sql_class.cc */ diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc index c28fea57c64..faf48b38fd0 100644 --- a/sql/sql_parse.cc +++ b/sql/sql_parse.cc @@ -218,14 +218,23 @@ void init_update_queries(void) sql_command_flags[SQLCOM_ALTER_EVENT]= CF_CHANGES_DATA; sql_command_flags[SQLCOM_DROP_EVENT]= CF_CHANGES_DATA; - sql_command_flags[SQLCOM_UPDATE]= CF_CHANGES_DATA | CF_HAS_ROW_COUNT; - sql_command_flags[SQLCOM_UPDATE_MULTI]= CF_CHANGES_DATA | CF_HAS_ROW_COUNT; - sql_command_flags[SQLCOM_INSERT]= CF_CHANGES_DATA | CF_HAS_ROW_COUNT; - sql_command_flags[SQLCOM_INSERT_SELECT]= CF_CHANGES_DATA | CF_HAS_ROW_COUNT; - sql_command_flags[SQLCOM_DELETE]= CF_CHANGES_DATA | CF_HAS_ROW_COUNT; - sql_command_flags[SQLCOM_DELETE_MULTI]= CF_CHANGES_DATA | CF_HAS_ROW_COUNT; - sql_command_flags[SQLCOM_REPLACE]= CF_CHANGES_DATA | CF_HAS_ROW_COUNT; - sql_command_flags[SQLCOM_REPLACE_SELECT]= CF_CHANGES_DATA | CF_HAS_ROW_COUNT; + sql_command_flags[SQLCOM_UPDATE]= CF_CHANGES_DATA | CF_HAS_ROW_COUNT | + CF_REEXECUTION_FRAGILE; + sql_command_flags[SQLCOM_UPDATE_MULTI]= CF_CHANGES_DATA | CF_HAS_ROW_COUNT | + CF_REEXECUTION_FRAGILE; + sql_command_flags[SQLCOM_INSERT]= CF_CHANGES_DATA | CF_HAS_ROW_COUNT | + CF_REEXECUTION_FRAGILE; + sql_command_flags[SQLCOM_INSERT_SELECT]= CF_CHANGES_DATA | CF_HAS_ROW_COUNT | + CF_REEXECUTION_FRAGILE; + sql_command_flags[SQLCOM_DELETE]= CF_CHANGES_DATA | CF_HAS_ROW_COUNT | + CF_REEXECUTION_FRAGILE; + sql_command_flags[SQLCOM_DELETE_MULTI]= CF_CHANGES_DATA | CF_HAS_ROW_COUNT | + CF_REEXECUTION_FRAGILE; + sql_command_flags[SQLCOM_REPLACE]= CF_CHANGES_DATA | CF_HAS_ROW_COUNT | + CF_REEXECUTION_FRAGILE; + sql_command_flags[SQLCOM_REPLACE_SELECT]= CF_CHANGES_DATA | CF_HAS_ROW_COUNT | + CF_REEXECUTION_FRAGILE; + sql_command_flags[SQLCOM_SELECT]= CF_REEXECUTION_FRAGILE; sql_command_flags[SQLCOM_SHOW_STATUS_PROC]= CF_STATUS_COMMAND; sql_command_flags[SQLCOM_SHOW_STATUS]= CF_STATUS_COMMAND; diff --git a/sql/sql_prepare.cc b/sql/sql_prepare.cc index c221e29e1d0..7550226adff 100644 --- a/sql/sql_prepare.cc +++ b/sql/sql_prepare.cc @@ -116,6 +116,39 @@ public: #endif }; +/** + If a metadata changed, report a respective error to trigger + re-prepare of a prepared statement. +*/ + +class Execute_observer: public Metadata_version_observer +{ +public: + virtual bool check_metadata_change(THD *thd); + /** Set to TRUE if metadata of some used table has changed since prepare */ + bool m_invalidated; +}; + +/** + Push an error to the error stack and return TRUE for now. + In future we must take special care of statements like CREATE + TABLE ... SELECT. Should we re-prepare such statements every + time? +*/ + +bool +Execute_observer::check_metadata_change(THD *thd) +{ + bool save_thd_no_warnings_for_error= thd->no_warnings_for_error; + DBUG_ENTER("Execute_observer::notify_about_metadata_change"); + + thd->no_warnings_for_error= TRUE; + my_error(ER_NEED_REPREPARE, MYF(0)); + thd->no_warnings_for_error= save_thd_no_warnings_for_error; + m_invalidated= TRUE; + DBUG_RETURN(TRUE); +} + /****************************************************************************/ /** @@ -156,20 +189,27 @@ public: bool set_name(LEX_STRING *name); inline void close_cursor() { delete cursor; cursor= 0; } inline bool is_in_use() { return flags & (uint) IS_IN_USE; } + inline bool is_protocol_text() const { return protocol == &thd->protocol_text; } bool prepare(const char *packet, uint packet_length); - bool execute(String *expanded_query, bool open_cursor); + bool execute_loop(String *expanded_query, + bool open_cursor, + uchar *packet_arg, uchar *packet_end_arg); /* Destroy this statement */ void deallocate(); private: /** - Store the parsed tree of a prepared statement here. - */ - LEX main_lex; - /** The memory root to allocate parsed tree elements (instances of Item, SELECT_LEX and other classes). */ MEM_ROOT main_mem_root; +private: + bool set_db(const char *db, uint db_length); + bool set_parameters(String *expanded_query, + uchar *packet, uchar *packet_end); + bool execute(String *expanded_query, bool open_cursor); + bool reprepare(); + bool validate_metadata(Prepared_statement *copy); + void swap_prepared_statement(Prepared_statement *copy); }; @@ -941,6 +981,55 @@ static bool emb_insert_params_with_log(Prepared_statement *stmt, #endif /*!EMBEDDED_LIBRARY*/ +/** + Setup data conversion routines using an array of parameter + markers from the original prepared statement. + Move the parameter data of the original prepared + statement to the new one. + + Used only when we re-prepare a prepared statement. + There are two reasons for this function to exist: + + 1) In the binary client/server protocol, parameter metadata + is sent only at first execute. Consequently, if we need to + reprepare a prepared statement at a subsequent execution, + we may not have metadata information in the packet. + In that case we use the parameter array of the original + prepared statement to setup parameter types of the new + prepared statement. + + 2) In the binary client/server protocol, we may supply + long data in pieces. When the last piece is supplied, + we assemble the pieces and convert them from client + character set to the connection character set. After + that the parameter value is only available inside + the parameter, the original pieces are lost, and thus + we can only assign the corresponding parameter of the + reprepared statement from the original value. + + @param[out] param_array_dst parameter markers of the new statement + @param[in] param_array_src parameter markers of the original + statement + @param[in] param_count total number of parameters. Is the + same in src and dst arrays, since + the statement query is the same + + @return this function never fails +*/ + +static void +swap_parameter_array(Item_param **param_array_dst, + Item_param **param_array_src, + uint param_count) +{ + Item_param **dst= param_array_dst; + Item_param **src= param_array_src; + Item_param **end= param_array_dst + param_count; + + for (; dst < end; ++src, ++dst) + (*dst)->set_param_type_and_swap_value(*src); +} + /** Assign prepared statement parameters from user variables. @@ -1264,7 +1353,7 @@ error: */ static int mysql_test_select(Prepared_statement *stmt, - TABLE_LIST *tables, bool text_protocol) + TABLE_LIST *tables) { THD *thd= stmt->thd; LEX *lex= stmt->lex; @@ -1300,7 +1389,7 @@ static int mysql_test_select(Prepared_statement *stmt, */ if (unit->prepare(thd, 0, 0)) goto error; - if (!lex->describe && !text_protocol) + if (!lex->describe && !stmt->is_protocol_text()) { /* Make copy of item list, as change_columns may change it */ List<Item> fields(lex->select_lex.item_list); @@ -1708,8 +1797,7 @@ static bool mysql_test_insert_select(Prepared_statement *stmt, TRUE error, error message is set in THD (but not sent) */ -static bool check_prepared_statement(Prepared_statement *stmt, - bool text_protocol) +static bool check_prepared_statement(Prepared_statement *stmt) { THD *thd= stmt->thd; LEX *lex= stmt->lex; @@ -1752,7 +1840,7 @@ static bool check_prepared_statement(Prepared_statement *stmt, break; case SQLCOM_SELECT: - res= mysql_test_select(stmt, tables, text_protocol); + res= mysql_test_select(stmt, tables); if (res == 2) { /* Statement and field info has already been sent */ @@ -1867,8 +1955,8 @@ static bool check_prepared_statement(Prepared_statement *stmt, break; } if (res == 0) - DBUG_RETURN(text_protocol? FALSE : (send_prep_stmt(stmt, 0) || - thd->protocol->flush())); + DBUG_RETURN(stmt->is_protocol_text() ? + FALSE : (send_prep_stmt(stmt, 0) || thd->protocol->flush())); error: DBUG_RETURN(TRUE); } @@ -2309,11 +2397,10 @@ void mysql_stmt_execute(THD *thd, char *packet_arg, uint packet_length) ulong flags= (ulong) packet[4]; /* Query text for binary, general or slow log, if any of them is open */ String expanded_query; -#ifndef EMBEDDED_LIBRARY uchar *packet_end= packet + packet_length; -#endif Prepared_statement *stmt; bool error; + bool open_cursor; DBUG_ENTER("mysql_stmt_execute"); packet+= 9; /* stmt_id + 5 bytes of flags */ @@ -2338,44 +2425,12 @@ void mysql_stmt_execute(THD *thd, char *packet_arg, uint packet_length) sp_cache_flush_obsolete(&thd->sp_proc_cache); sp_cache_flush_obsolete(&thd->sp_func_cache); -#ifndef EMBEDDED_LIBRARY - if (stmt->param_count) - { - uchar *null_array= packet; - if (setup_conversion_functions(stmt, &packet, packet_end) || - stmt->set_params(stmt, null_array, packet, packet_end, - &expanded_query)) - goto set_params_data_err; - } -#else - /* - In embedded library we re-install conversion routines each time - we set params, and also we don't need to parse packet. - So we do it in one function. - */ - if (stmt->param_count && stmt->set_params_data(stmt, &expanded_query)) - goto set_params_data_err; -#endif - if (!(specialflag & SPECIAL_NO_PRIOR)) - my_pthread_setprio(pthread_self(),QUERY_PRIOR); + open_cursor= test(flags & (ulong) CURSOR_TYPE_READ_ONLY); - /* - If the free_list is not empty, we'll wrongly free some externally - allocated items when cleaning up after validation of the prepared - statement. - */ - DBUG_ASSERT(thd->free_list == NULL); + stmt->execute_loop(&expanded_query, open_cursor, packet, packet_end); - error= stmt->execute(&expanded_query, - test(flags & (ulong) CURSOR_TYPE_READ_ONLY)); - if (!(specialflag & SPECIAL_NO_PRIOR)) - my_pthread_setprio(pthread_self(), WAIT_PRIOR); DBUG_VOID_RETURN; -set_params_data_err: - my_error(ER_WRONG_ARGUMENTS, MYF(0), "mysql_stmt_execute"); - reset_stmt_params(stmt); - DBUG_VOID_RETURN; } @@ -2421,24 +2476,8 @@ void mysql_sql_stmt_execute(THD *thd) DBUG_PRINT("info",("stmt: 0x%lx", (long) stmt)); - /* - If the free_list is not empty, we'll wrongly free some externally - allocated items when cleaning up after validation of the prepared - statement. - */ - DBUG_ASSERT(thd->free_list == NULL); - - if (stmt->set_params_from_vars(stmt, lex->prepared_stmt_params, - &expanded_query)) - goto set_params_data_err; - - (void) stmt->execute(&expanded_query, FALSE); - - DBUG_VOID_RETURN; + (void) stmt->execute_loop(&expanded_query, FALSE, NULL, NULL); -set_params_data_err: - my_error(ER_WRONG_ARGUMENTS, MYF(0), "EXECUTE"); - reset_stmt_params(stmt); DBUG_VOID_RETURN; } @@ -2742,7 +2781,7 @@ Select_fetch_protocol_binary::send_data(List<Item> &fields) ****************************************************************************/ Prepared_statement::Prepared_statement(THD *thd_arg, Protocol *protocol_arg) - :Statement(&main_lex, &main_mem_root, + :Statement(0, &main_mem_root, INITIALIZED, ++thd_arg->statement_id_counter), thd(thd_arg), result(thd_arg), @@ -2813,7 +2852,11 @@ Prepared_statement::~Prepared_statement() like Item_param, don't free everything until free_items() */ free_items(); - delete lex->result; + if (lex) + { + delete lex->result; + delete (st_lex_local *) lex; + } free_root(&main_mem_root, MYF(0)); DBUG_VOID_RETURN; } @@ -2849,6 +2892,34 @@ bool Prepared_statement::set_name(LEX_STRING *name_arg) return name.str == 0; } + +/** + Remember the current database. + + We must reset/restore the current database during execution of + a prepared statement since it affects execution environment: + privileges, @@character_set_database, and other. + + @return Returns an error if out of memory. +*/ + +bool +Prepared_statement::set_db(const char *db_arg, uint db_length_arg) +{ + /* Remember the current database. */ + if (db_arg && db_length_arg) + { + db= this->strmake(db_arg, db_length_arg); + db_length= db_length_arg; + } + else + { + db= NULL; + db_length= 0; + } + return db_arg != NULL && db == NULL; +} + /************************************************************************** Common parts of mysql_[sql]_stmt_prepare, mysql_[sql]_stmt_execute. Essentially, these functions do all the magic of preparing/executing @@ -2890,6 +2961,12 @@ bool Prepared_statement::prepare(const char *packet, uint packet_len) */ status_var_increment(thd->status_var.com_stmt_prepare); + if (! (lex= new (mem_root) st_lex_local)) + DBUG_RETURN(TRUE); + + if (set_db(thd->db, thd->db_length)) + DBUG_RETURN(TRUE); + /* alloc_query() uses thd->memroot && thd->query, so we should call both of backup_statement() and backup_query_arena() here. @@ -2917,19 +2994,6 @@ bool Prepared_statement::prepare(const char *packet, uint packet_len) lex->set_trg_event_type_for_tables(); - /* Remember the current database. */ - - if (thd->db && thd->db_length) - { - db= this->strmake(thd->db, thd->db_length); - db_length= thd->db_length; - } - else - { - db= NULL; - db_length= 0; - } - /* While doing context analysis of the query (in check_prepared_statement) we allocate a lot of additional memory: for open tables, JOINs, derived @@ -2953,7 +3017,7 @@ bool Prepared_statement::prepare(const char *packet, uint packet_len) */ if (error == 0) - error= check_prepared_statement(this, name.str != 0); + error= check_prepared_statement(this); /* Currently CREATE PROCEDURE/TRIGGER/EVENT are prohibited in prepared @@ -3000,6 +3064,293 @@ bool Prepared_statement::prepare(const char *packet, uint packet_len) DBUG_RETURN(error); } + +bool +Prepared_statement::set_parameters(String *expanded_query, + uchar *packet, uchar *packet_end) +{ + bool is_sql_ps= packet == NULL; + + if (is_sql_ps) + { + /* SQL prepared statement */ + if (set_params_from_vars(this, thd->lex->prepared_stmt_params, + expanded_query)) + goto set_params_data_err; + } + else if (param_count) + { +#ifndef EMBEDDED_LIBRARY + uchar *null_array= packet; + if (setup_conversion_functions(this, &packet, packet_end) || + set_params(this, null_array, packet, packet_end, + expanded_query)) + goto set_params_data_err; +#else + /* + In embedded library we re-install conversion routines each time + we set params, and also we don't need to parse packet. + So we do it in one function. + */ + if (set_params_data(this, expanded_query)) + goto set_params_data_err; +#endif + } + return FALSE; +set_params_data_err: + my_error(ER_WRONG_ARGUMENTS, MYF(0), + is_sql_ps ? "EXECUTE" : "mysql_stmt_execute"); + reset_stmt_params(this); + return TRUE; +} + + +/** + Execute a prepared statement. Re-prepare it a limited number + of times if necessary. + + Try to execute a prepared statement. If there is a metadata + validation error, prepare a new copy of the prepared statement, + swap the old and the new statements, and try again. + If there is a validation error again, repeat the above, but + perform no more than MAX_REPREPARE_ATTEMPTS. + + @note We have to try several times in a loop since we + release metadata locks on tables after prepared statement + prepare. Therefore, a DDL statement may sneak in between prepare + and execute of a new statement. If this happens repeatedly + more than MAX_REPREPARE_ATTEMPTS times, we give up. + + In future we need to be able to keep the metadata locks between + prepare and execute, but right now open_and_lock_tables(), as + well as close_thread_tables() are buried deep inside + execution code (mysql_execute_command()). + + @return TRUE if an error, FALSE if success + @retval TRUE either MAX_REPREPARE_ATTEMPTS has been reached, + or some general error + @retval FALSE successfully executed the statement, perhaps + after having reprepared it a few times. +*/ + +bool +Prepared_statement::execute_loop(String *expanded_query, + bool open_cursor, + uchar *packet, + uchar *packet_end) +{ + const int MAX_REPREPARE_ATTEMPTS= 3; + Execute_observer execute_observer; + bool error; + int reprepare_attempt= 0; + + if (set_parameters(expanded_query, packet, packet_end)) + return TRUE; + +reexecute: + execute_observer.m_invalidated= FALSE; + + /* + If the free_list is not empty, we'll wrongly free some externally + allocated items when cleaning up after validation of the prepared + statement. + */ + DBUG_ASSERT(thd->free_list == NULL); + + /* + Install the metadata observer. If some metadata version is + different from prepare time and an observer is installed, + the observer method will be invoked to push an error into + the error stack. + */ + if (sql_command_flags[lex->sql_command] & + CF_REEXECUTION_FRAGILE) + { + thd->m_metadata_observer= &execute_observer; + } + + if (!(specialflag & SPECIAL_NO_PRIOR)) + my_pthread_setprio(pthread_self(),QUERY_PRIOR); + + error= execute(expanded_query, open_cursor) || thd->is_error(); + + if (!(specialflag & SPECIAL_NO_PRIOR)) + my_pthread_setprio(pthread_self(), WAIT_PRIOR); + + thd->m_metadata_observer= 0; + + if (error && !thd->is_fatal_error && !thd->killed && + execute_observer.m_invalidated && + reprepare_attempt++ < MAX_REPREPARE_ATTEMPTS) + { + thd->clear_error(); + + error= reprepare(); + + if (! error) /* Success */ + goto reexecute; + } + reset_stmt_params(this); + + return error; +} + + +/** + Reprepare this prepared statement. + + Currently this is implemented by creating a new prepared + statement, preparing it with the original query and then + swapping the new statement and the original one. + + @retval TRUE an error occurred. Possible errors include + incompatibility of new and old result set + metadata + @retval FALSE success, the statement has been reprepared +*/ + +bool +Prepared_statement::reprepare() +{ + char saved_cur_db_name_buf[NAME_LEN+1]; + LEX_STRING saved_cur_db_name= + { saved_cur_db_name_buf, sizeof(saved_cur_db_name_buf) }; + LEX_STRING stmt_db_name= { db, db_length }; + Prepared_statement *copy; + bool cur_db_changed; + bool error= TRUE; + + status_var_increment(thd->status_var.com_stmt_reprepare); + + copy= new Prepared_statement(thd, &thd->protocol_text); + + if (! copy) + return TRUE; + + if (mysql_opt_change_db(thd, &stmt_db_name, &saved_cur_db_name, TRUE, + &cur_db_changed)) + goto end; + + error= (name.str && copy->set_name(&name) || + copy->prepare(query, query_length) || + validate_metadata(copy)); + + if (cur_db_changed) + mysql_change_db(thd, &saved_cur_db_name, TRUE); + + if (! error) + { + swap_prepared_statement(copy); + swap_parameter_array(param_array, copy->param_array, param_count); + is_reprepared= TRUE; + /* + Clear possible warnigns during re-prepare, it has to be completely + transparent to the user. We use mysql_reset_errors() since + there were no separate query id issued for re-prepare. + */ + mysql_reset_errors(thd, TRUE); + } +end: + delete copy; + return error; +} + + +/** + Validate statement result set metadata (if the statement returns + a result set). + + Currently we only check that the number of columns of the result + set did not change. + This is a helper method used during re-prepare. + + @param[in] copy the re-prepared prepared statement to verify + the metadata of + + @retval TRUE error, ER_PS_NEED_REBIND is reported + @retval FALSE statement return no or compatible metadata +*/ + + +bool Prepared_statement::validate_metadata(Prepared_statement *copy) +{ + List_iterator_fast<Item> it_org(lex->select_lex.item_list); + List_iterator_fast<Item> it_new(copy->lex->select_lex.item_list); + Item *item_org; + Item *item_new; + + /** + If this is an SQL prepared statement or EXPLAIN, + return FALSE -- the metadata of the original SELECT, + if any, has not been sent to the client. + */ + if (is_protocol_text() || lex->describe) + return FALSE; + + if (lex->select_lex.item_list.elements != + copy->lex->select_lex.item_list.elements) + { + /** Column counts mismatch. */ + my_error(ER_PS_REBIND, MYF(0)); + return TRUE; + } + + return FALSE; +} + + +/** + Replace the original prepared statement with a prepared copy. + + This is a private helper that is used as part of statement + reprepare + + @return This function does not return any errors. +*/ + +void +Prepared_statement::swap_prepared_statement(Prepared_statement *copy) +{ + Statement tmp_stmt; + + /* Swap memory roots. */ + swap_variables(MEM_ROOT, main_mem_root, copy->main_mem_root); + + /* Swap the arenas */ + tmp_stmt.set_query_arena(this); + set_query_arena(copy); + copy->set_query_arena(&tmp_stmt); + + /* Swap the statement parent classes */ + tmp_stmt.set_statement(this); + set_statement(copy); + copy->set_statement(&tmp_stmt); + + /* Swap ids back, we need the original id */ + swap_variables(ulong, id, copy->id); + /* Swap mem_roots back, they must continue pointing at the main_mem_roots */ + swap_variables(MEM_ROOT *, mem_root, copy->mem_root); + /* + Swap the old and the new parameters array. The old array + is allocated in the old arena. + */ + swap_variables(Item_param **, param_array, copy->param_array); + /* Swap flags: this is perhaps unnecessary */ + swap_variables(uint, flags, copy->flags); + /* Swap names, the old name is allocated in the wrong memory root */ + swap_variables(LEX_STRING, name, copy->name); + /* Ditto */ + swap_variables(char *, db, copy->db); + + DBUG_ASSERT(db_length == copy->db_length); + DBUG_ASSERT(param_count == copy->param_count); + DBUG_ASSERT(thd == copy->thd); + last_error[0]= '\0'; + last_errno= 0; + /* Do not swap protocols, the copy always has protocol_text */ +} + + /** Execute a prepared statement. @@ -3162,10 +3513,7 @@ bool Prepared_statement::execute(String *expanded_query, bool open_cursor) DBUG_ASSERT(! (error && cursor)); if (! cursor) - { cleanup_stmt(); - reset_stmt_params(this); - } thd->set_statement(&stmt_backup); thd->stmt_arena= old_stmt_arena; diff --git a/sql/table.h b/sql/table.h index d448485a117..2b3c9b8d5b1 100644 --- a/sql/table.h +++ b/sql/table.h @@ -437,6 +437,105 @@ typedef struct st_table_share return table_map_id; } + /** + Convert unrelated members of TABLE_SHARE to one enum + representing its metadata type. + + @todo perhaps we need to have a member instead of a function. + */ + enum enum_metadata_type get_metadata_type() const + { + if (is_view) + return METADATA_VIEW; + switch (tmp_table) { + case NO_TMP_TABLE: + return METADATA_BASE_TABLE; + case SYSTEM_TMP_TABLE: + return METADATA_I_S_TABLE; + default: + return METADATA_TMP_TABLE; + } + } + /** + Return a table metadata version. + * for base tables, we return table_map_id. + It is assigned from a global counter incremented for each + new table loaded into the table definition cache (TDC). + * for temporary tables it's table_map_id again. But for + temporary tables table_map_id is assigned from + thd->query_id. The latter is assigned from a thread local + counter incremented for every new SQL statement. Since + temporary tables are thread-local, each temporary table + gets a unique id. + * for everything else (views, information schema tables), + the version id is zero. + + This choice of version id is a large compromise + to have a working prepared statement validation in 5.1. In + future version ids will be persistent, as described in WL#4180. + + Let's try to explain why and how this limited solution allows + to validate prepared statements. + + Firstly, spaces (in mathematical sense) of version numbers + never intersect for different metadata types. Therefore, + version id of a temporary table is never compared with + a version id of a view or a temporary table, and vice versa. + + Secondly, for base tables, we know that each DDL flushes the + respective share from the TDC. This ensures that whenever + a table is altered or dropped and recreated, it gets a new + version id. + Unfortunately, since elements of the TDC are also flushed on + LRU basis, this choice of version ids leads to false positives. + E.g. when the TDC size is too small, we may have a SELECT + * FROM INFORMATION_SCHEMA.TABLES flush all its elements, which + in turn will lead to a validation error and a subsequent + reprepare of all prepared statements. This is + considered acceptable, since as long as prepared statements are + automatically reprepared, spurious invalidation is only + a performance hit. Besides, no better simple solution exists. + + For temporary tables, using thd->query_id ensures that if + a temporary table was altered or recreated, a new version id is + assigned. This suits validation needs very well and will perhaps + never change. + + Metadata of information schema tables never changes. + Thus we can safely assume 0 for a good enough version id. + + Views are a special and tricky case. A view is always inlined + into the parse tree of a prepared statement at prepare. + Thus, when we execute a prepared statement, the parse tree + will not get modified even if the view is replaced with another + view. Therefore, we can safely choose 0 for version id of + views and effectively never invalidate a prepared statement + when a view definition is altered. Note, that this leads to + wrong binary log in statement-based replication, since we log + prepared statement execution in form Query_log_events + containing conventional statements. But since there is no + metadata locking for views, the very same problem exists for + conventional statements alone, as reported in Bug#25144. The only + difference between prepared and conventional execution is, + effectively, that for prepared statements the race condition + window is much wider. + In 6.0 we plan to support view metadata locking (WL#3726) and + extend table definition cache to cache views (WL#4298). + When this is done, views will be handled in the same fashion + as the base tables. + + Finally, by taking into account metadata type, we always + track that a change has taken place when a view is replaced + with a base table, a base table is replaced with a temporary + table and so on. + + @sa TABLE_LIST::is_metadata_version_equal() + */ + ulong get_metadata_version() const + { + return tmp_table == SYSTEM_TMP_TABLE || is_view ? 0 : table_map_id; + } + } TABLE_SHARE; @@ -1232,6 +1331,33 @@ struct TABLE_LIST child_def_version= ~0UL; } + /** + Compare the version of metadata from the previous execution + (if any) with values obtained from the current table + definition cache element. + + @sa check_and_update_metadata_version() + */ + inline + bool is_metadata_version_equal(TABLE_SHARE *s) const + { + return (m_metadata_type == s->get_metadata_type() && + m_metadata_version == s->get_metadata_version()); + } + + /** + Record the value of metadata version of the corresponding + table definition cache element in this parse tree node. + + @sa check_and_update_metadata_version() + */ + inline + void set_metadata_version(TABLE_SHARE *s) + { + m_metadata_type= s->get_metadata_type(); + m_metadata_version= s->get_metadata_version(); + } + private: bool prep_check_option(THD *thd, uint8 check_opt_type); bool prep_where(THD *thd, Item **conds, bool no_where_clause); @@ -1242,6 +1368,10 @@ private: /* Remembered MERGE child def version. See top comment in ha_myisammrg.cc */ ulong child_def_version; + /** See comments for set_metadata_version() */ + enum enum_metadata_type m_metadata_type; + /** See comments for set_metadata_version() */ + ulong m_metadata_version; }; class Item; diff --git a/tests/mysql_client_test.c b/tests/mysql_client_test.c index 0df2d4ed4a5..748f04b11d3 100644 --- a/tests/mysql_client_test.c +++ b/tests/mysql_client_test.c @@ -11132,7 +11132,7 @@ static void test_bug4236() int rc; MYSQL_STMT backup; - myheader("test_bug4296"); + myheader("test_bug4236"); stmt= mysql_stmt_init(mysql); @@ -17383,6 +17383,123 @@ static void test_bug28386() DBUG_VOID_RETURN; } +static void test_wl4166() +{ + MYSQL_STMT *stmt; + int int_data; + char str_data[50]; + char tiny_data; + short small_data; + longlong big_data; + float real_data; + double double_data; + ulong length[7]; + my_bool is_null[7]; + MYSQL_BIND my_bind[7]; + int rc; + int i; + + myheader("test_wl4166"); + + rc= mysql_query(mysql, "DROP TABLE IF EXISTS table_4166"); + myquery(rc); + + rc= mysql_query(mysql, "CREATE TABLE table_4166(col1 tinyint NOT NULL, " + "col2 varchar(15), col3 int, " + "col4 smallint, col5 bigint, " + "col6 float, col7 double, " + "colX varchar(10) default NULL)"); + myquery(rc); + + stmt= mysql_simple_prepare(mysql, + "INSERT INTO table_4166(col1, col2, col3, col4, col5, col6, col7) " + "VALUES(?, ?, ?, ?, ?, ?, ?)"); + check_stmt(stmt); + + verify_param_count(stmt, 7); + + /* tinyint */ + my_bind[0].buffer_type= MYSQL_TYPE_TINY; + my_bind[0].buffer= (void *)&tiny_data; + /* string */ + my_bind[1].buffer_type= MYSQL_TYPE_STRING; + my_bind[1].buffer= (void *)str_data; + my_bind[1].buffer_length= 1000; /* Max string length */ + /* integer */ + my_bind[2].buffer_type= MYSQL_TYPE_LONG; + my_bind[2].buffer= (void *)&int_data; + /* short */ + my_bind[3].buffer_type= MYSQL_TYPE_SHORT; + my_bind[3].buffer= (void *)&small_data; + /* bigint */ + my_bind[4].buffer_type= MYSQL_TYPE_LONGLONG; + my_bind[4].buffer= (void *)&big_data; + /* float */ + my_bind[5].buffer_type= MYSQL_TYPE_FLOAT; + my_bind[5].buffer= (void *)&real_data; + /* double */ + my_bind[6].buffer_type= MYSQL_TYPE_DOUBLE; + my_bind[6].buffer= (void *)&double_data; + + for (i= 0; i < (int) array_elements(my_bind); i++) + { + my_bind[i].length= &length[i]; + my_bind[i].is_null= &is_null[i]; + is_null[i]= 0; + } + + rc= mysql_stmt_bind_param(stmt, my_bind); + check_execute(stmt, rc); + + int_data= 320; + small_data= 1867; + big_data= 1000; + real_data= 2; + double_data= 6578.001; + + /* now, execute the prepared statement to insert 10 records.. */ + for (tiny_data= 0; tiny_data < 10; tiny_data++) + { + length[1]= my_sprintf(str_data, (str_data, "MySQL%d", int_data)); + rc= mysql_stmt_execute(stmt); + check_execute(stmt, rc); + int_data += 25; + small_data += 10; + big_data += 100; + real_data += 1; + double_data += 10.09; + } + + /* force a re-prepare with some DDL */ + + rc= mysql_query(mysql, + "ALTER TABLE table_4166 change colX colX varchar(20) default NULL"); + myquery(rc); + + /* + execute the prepared statement again, + without changing the types of parameters already bound. + */ + + for (tiny_data= 50; tiny_data < 60; tiny_data++) + { + length[1]= my_sprintf(str_data, (str_data, "MySQL%d", int_data)); + rc= mysql_stmt_execute(stmt); + check_execute(stmt, rc); + int_data += 25; + small_data += 10; + big_data += 100; + real_data += 1; + double_data += 10.09; + } + + mysql_stmt_close(stmt); + + rc= mysql_query(mysql, "DROP TABLE table_4166"); + myquery(rc); + +} + /* Read and parse arguments and MySQL options from my.cnf */ @@ -17689,6 +17806,7 @@ static struct my_tests_st my_tests[]= { { "test_bug31418", test_bug31418 }, { "test_bug31669", test_bug31669 }, { "test_bug28386", test_bug28386 }, + { "test_wl4166", test_wl4166 }, { 0, 0 } }; |