From 41697008fefc03d6dc50c90331f1b4f0de0e0037 Mon Sep 17 00:00:00 2001 From: Nikita Malyavin Date: Tue, 29 Nov 2022 20:40:07 +0100 Subject: [PATCH] MDEV-29069 follow-up: improve DEFAULT rules previously, fields with DEFAULTs were allowed just when expression is deterministic. In case of online alter, we should recursively check that underlying fields of expression also either have explicit values, or have DEFAULT following this validity rule. --- .../main/alter_table_online_debug.result | 42 +++++++++++++ mysql-test/main/alter_table_online_debug.test | 36 +++++++++++ sql/field.h | 2 +- sql/log_event_server.cc | 59 +++++++++++++++---- 4 files changed, 127 insertions(+), 12 deletions(-) diff --git a/mysql-test/main/alter_table_online_debug.result b/mysql-test/main/alter_table_online_debug.result index dad92f43006..b52187bfc4c 100644 --- a/mysql-test/main/alter_table_online_debug.result +++ b/mysql-test/main/alter_table_online_debug.result @@ -1111,6 +1111,48 @@ connection default; Warnings: Note 1105 Key chosen: 0 Note 1105 Key chosen: 0 +# +# Useful UNIQUE, though a virtual column on another extra field +# +create or replace table t (a int primary key, b int default (a+1)); +insert into t values (10, 10),(20, 20),(30, 30); +set debug_sync= 'alter_table_online_downgraded signal downgraded wait_for goforit'; +alter table t drop primary key, add c int default(a), +add d int as (c) stored unique, algorithm=copy, lock=none; +connection con2; +set debug_sync= 'now wait_for downgraded'; +delete from t where a = 20; +update t set a = a + 2 where a = 10; +set debug_sync= 'now signal goforit'; +connection default; +Warnings: +Note 1105 Key chosen: 0 +Note 1105 Key chosen: 0 +select * from t; +a b c d +12 10 12 12 +30 30 30 30 +# +# Now this index is not usable (missing DEFAULT on field c) +# +create or replace table t (a int primary key, b int); +insert into t values (10, 10),(20, 20),(30, 30); +set debug_sync= 'alter_table_online_downgraded signal downgraded wait_for goforit'; +alter table t drop primary key, add c real default(rand(a)), +add d real as (c) stored unique, algorithm=copy, lock=none; +connection con2; +set debug_sync= 'now wait_for downgraded'; +delete from t where a = 20; +update t set a = a + 2 where a = 10; +set debug_sync= 'now signal goforit'; +connection default; +Warnings: +Note 1105 Key chosen: -1 +Note 1105 Key chosen: -1 +select a, b from t; +a b +12 10 +30 30 drop table t; set debug_sync= reset; set debug_dbug= @old_debug; diff --git a/mysql-test/main/alter_table_online_debug.test b/mysql-test/main/alter_table_online_debug.test index 4431c266ed4..f9cadcb59cf 100644 --- a/mysql-test/main/alter_table_online_debug.test +++ b/mysql-test/main/alter_table_online_debug.test @@ -1284,6 +1284,42 @@ set debug_sync= 'now signal goforit'; --reap +--echo # +--echo # Useful UNIQUE, though a virtual column on another extra field +--echo # +create or replace table t (a int primary key, b int default (a+1)); +insert into t values (10, 10),(20, 20),(30, 30); +set debug_sync= 'alter_table_online_downgraded signal downgraded wait_for goforit'; +--send +alter table t drop primary key, add c int default(a), + add d int as (c) stored unique, algorithm=copy, lock=none; +--connection con2 +set debug_sync= 'now wait_for downgraded'; +delete from t where a = 20; +update t set a = a + 2 where a = 10; +set debug_sync= 'now signal goforit'; +--connection default +--reap +select * from t; + +--echo # +--echo # Now this index is not usable (missing DEFAULT on field c) +--echo # +create or replace table t (a int primary key, b int); +insert into t values (10, 10),(20, 20),(30, 30); +set debug_sync= 'alter_table_online_downgraded signal downgraded wait_for goforit'; +--send +alter table t drop primary key, add c real default(rand(a)), + add d real as (c) stored unique, algorithm=copy, lock=none; +--connection con2 +set debug_sync= 'now wait_for downgraded'; +delete from t where a = 20; +update t set a = a + 2 where a = 10; +set debug_sync= 'now signal goforit'; +--connection default +--reap +select a, b from t; + # Cleanup drop table t; set debug_sync= reset; diff --git a/sql/field.h b/sql/field.h index 94f1d977cdd..477dc0fe282 100644 --- a/sql/field.h +++ b/sql/field.h @@ -1192,7 +1192,7 @@ public: { bitmap_set_bit(&table->has_value_set, field_index); } - bool has_explicit_value() + bool has_explicit_value() const { return bitmap_is_set(&table->has_value_set, field_index); } diff --git a/sql/log_event_server.cc b/sql/log_event_server.cc index bf88511c8a2..0e994a456b0 100644 --- a/sql/log_event_server.cc +++ b/sql/log_event_server.cc @@ -7096,6 +7096,51 @@ record_compare_exit: record_compare_differ: return true; } +/** + Traverses default item expr of a field, and underlying field's default values. + If it is an extra field and has no value replicated, then its default expr + should be also checked. + */ +class Rpl_key_part_checker: public Field_enumerator +{ + bool online_alter; + Field *next_number_field; + bool field_usable; +public: + + + void visit_field(Item_field *item) override + { + if (!field_usable) + return; + field_usable= check_field(item->field); + } + + bool check_field(Field *f) + { + if (f->has_explicit_value()) + return true; + + if ((!f->vcol_info && !online_alter) || f == next_number_field) + return false; + + Virtual_column_info *computed= f->vcol_info ? f->vcol_info + : f->default_value; + + if (computed == NULL) + return true; // No DEFAULT, or constant DEFAULT + + // Deterministic DEFAULT or vcol expression + return !(computed->flags & VCOL_NOT_STRICTLY_DETERMINISTIC) + && !computed->expr->walk(&Item::enumerate_field_refs_processor, + false, this) + && field_usable; + } + + Rpl_key_part_checker(bool online_alter, Field *next_number_field): + online_alter(online_alter), next_number_field(next_number_field), + field_usable(true) {} +}; /** @@ -7126,19 +7171,11 @@ uint Rows_log_event::find_key_parts(const KEY *key) const } } + Rpl_key_part_checker key_part_checker(online_alter, + m_table->found_next_number_field); for (p= 0; p < key->user_defined_key_parts; p++) { - Field *f= key->key_part[p].field; - /* - in the online alter case (but not in replication) we don't have - to reject an index if it includes new columns, as long as - their values are deterministic. - */ - bool non_deterministic_default= f->default_value && - f->default_value->flags & VCOL_NOT_STRICTLY_DETERMINISTIC; - bool next_number_field= f == f->table->next_number_field; - if (!bitmap_is_set(&m_table->has_value_set, f->field_index) && - (!online_alter || non_deterministic_default || next_number_field)) + if (!key_part_checker.check_field(key->key_part[p].field)) break; } return p;