diff options
Diffstat (limited to 'sql/field.h')
| -rw-r--r-- | sql/field.h | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/sql/field.h b/sql/field.h index 6cd435f2bec..b24561d7dd9 100644 --- a/sql/field.h +++ b/sql/field.h @@ -1,6 +1,6 @@ #ifndef FIELD_INCLUDED #define FIELD_INCLUDED -/* Copyright (c) 2000, 2013, Oracle and/or its affiliates. +/* Copyright (c) 2000, 2015, Oracle and/or its affiliates. Copyright (c) 2008, 2015, MariaDB This program is free software; you can redistribute it and/or modify @@ -1308,6 +1308,16 @@ public: /* Hash value */ virtual void hash(ulong *nr, ulong *nr2); +/** + Checks whether a string field is part of write_set. + + @return + FALSE - If field is not char/varchar/.... + - If field is char/varchar/.. and is not part of write set. + TRUE - If field is char/varchar/.. and is part of write set. +*/ + virtual bool is_updatable() const { return FALSE; } + /* Check whether the field can be used as a join attribute in hash join */ virtual bool hash_join_is_possible() { return TRUE; } virtual bool eq_cmp_as_binary() { return TRUE; } @@ -1582,6 +1592,14 @@ public: int store_decimal(const my_decimal *d); uint32 max_data_length() const; + + bool is_updatable() const + { + DBUG_ASSERT(table && table->write_set); + return bitmap_is_set(table->write_set, field_index); + } + bool match_collation_to_optimize_range() const { return true; } + bool can_optimize_keypart_ref(const Item_bool_func *cond, const Item *item) const; bool can_optimize_hash_join(const Item_bool_func *cond, |