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authorunknown <sanja@askmonty.org>2010-07-10 13:37:30 +0300
committerunknown <sanja@askmonty.org>2010-07-10 13:37:30 +0300
commitceb5468fd8bc9675d514949dd60c5bd7276bf3f4 (patch)
tree023ae4949798e834f42fa4fd9d34b3bfddb07385 /sql/sql_expression_cache.h
parente5f238a05152efbd4b05425511eeed59c3026779 (diff)
downloadmariadb-git-ceb5468fd8bc9675d514949dd60c5bd7276bf3f4.tar.gz
Subquery cache (MWL#66) added.
libmysqld/Makefile.am: The new file added. mysql-test/r/index_merge_myisam.result: subquery_cache optimization option added. mysql-test/r/myisam_mrr.result: subquery_cache optimization option added. mysql-test/r/subquery_cache.result: The subquery cache tests added. mysql-test/r/subselect3.result: Subquery cache switched off to avoid changing read statistics. mysql-test/r/subselect3_jcl6.result: Subquery cache switched off to avoid changing read statistics. mysql-test/r/subselect_no_mat.result: subquery_cache optimization option added. mysql-test/r/subselect_no_opts.result: subquery_cache optimization option added. mysql-test/r/subselect_no_semijoin.result: subquery_cache optimization option added. mysql-test/r/subselect_sj.result: subquery_cache optimization option added. mysql-test/r/subselect_sj_jcl6.result: subquery_cache optimization option added. mysql-test/t/subquery_cache.test: The subquery cache tests added. mysql-test/t/subselect3.test: Subquery cache switched off to avoid changing read statistics. sql/CMakeLists.txt: The new file added. sql/Makefile.am: The new files added. sql/item.cc: Expression cache item (Item_cache_wrapper) added. Item_ref and Item_field fixed for correct usage of result field and fast resolwing in SP. sql/item.h: Expression cache item (Item_cache_wrapper) added. Item_ref and Item_field fixed for correct usage of result field and fast resolwing in SP. sql/item_cmpfunc.cc: Subquery cache added. sql/item_cmpfunc.h: Subquery cache added. sql/item_subselect.cc: Subquery cache added. sql/item_subselect.h: Subquery cache added. sql/item_sum.cc: Registration of subquery parameters added. sql/mysql_priv.h: subquery_cache optimization option added. sql/mysqld.cc: subquery_cache optimization option added. sql/opt_range.cc: Fix due to subquery cache. sql/opt_subselect.cc: Parameters of the function cahnged. sql/procedure.h: .h file guard added. sql/sql_base.cc: Registration of subquery parameters added. sql/sql_class.cc: Option to allow add indeces to temporary table. sql/sql_class.h: Item iterators added. Option to allow add indeces to temporary table. sql/sql_expression_cache.cc: Expression cache for caching subqueries added. sql/sql_expression_cache.h: Expression cache for caching subqueries added. sql/sql_lex.cc: Registration of subquery parameters added. sql/sql_lex.h: Registration of subqueries and subquery parameters added. sql/sql_select.cc: Subquery cache added. sql/sql_select.h: Subquery cache added. sql/sql_union.cc: A new parameter to the function added. sql/sql_update.cc: A new parameter to the function added. sql/table.cc: Procedures to manage temporarty tables index added. sql/table.h: Procedures to manage temporarty tables index added. storage/maria/ha_maria.cc: Fix of handler to allow destoy a table in case of error during the table creation. storage/maria/ha_maria.h: .h file guard added. storage/myisam/ha_myisam.cc: Fix of handler to allow destoy a table in case of error during the table creation.
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+#ifndef SQL_EXPRESSION_CACHE_INCLUDED
+#define SQL_EXPRESSION_CACHE_INCLUDED
+
+#include "sql_select.h"
+
+/**
+ Interface for expression cache
+
+ @note
+ Parameters of an expression cache interface are set on the creation of the
+ cache. They are passed when a cache object of the implementation class is
+ constructed. That's why they are not visible in this interface.
+*/
+
+extern ulonglong subquery_cache_miss, subquery_cache_hit;
+
+class Expression_cache :public Sql_alloc
+{
+public:
+ enum result {ERROR, HIT, MISS};
+
+ Expression_cache(){};
+ virtual ~Expression_cache() {};
+ /**
+ Shall check the presence of expression value in the cache for a given
+ set of values of the expression parameters. Return the result of the
+ expression if it's found in the cache.
+ */
+ virtual result check_value(Item **value)= 0;
+ /**
+ Shall put the value of an expression for given set of its parameters
+ into the expression cache
+ */
+ virtual my_bool put_value(Item *value)= 0;
+};
+
+struct st_table_ref;
+struct st_join_table;
+class Item_field;
+
+
+/**
+ Implementation of expression cache over a temporary table
+*/
+
+class Expression_cache_tmptable :public Expression_cache
+{
+public:
+ Expression_cache_tmptable(THD *thd, List<Item*> &dependants, Item *value);
+ virtual ~Expression_cache_tmptable();
+ virtual result check_value(Item **value);
+ virtual my_bool put_value(Item *value);
+
+private:
+ void init();
+ bool make_equalities();
+
+ /* tmp table parameters */
+ TMP_TABLE_PARAM cache_table_param;
+ /* temporary table to store this cache */
+ TABLE *cache_table;
+ /* Thread handle for the temporary table */
+ THD *table_thd;
+ /* TABLE_REF for index lookup */
+ struct st_table_ref ref;
+ /* Cached result */
+ Item_field *cached_result;
+ /* List of references to the parameters of the expression */
+ List<Item*> *list;
+ /* List of items */
+ List<Item> items;
+ /* Value Item example */
+ Item *val;
+ /* Expression to check after index lookup */
+ Item *equalities;
+ /* Set on if the object has been succesfully initialized with init() */
+ bool inited;
+};
+
+#endif /* SQL_EXPRESSION_CACHE_INCLUDED */