database/mariadb-columnstore-engine
1
0
Fork 0
mirror of https://github.com/mariadb-corporation/mariadb-columnstore-engine.git synced 2025-10-22 22:32:34 +03:00
Code Activity
Files
9d83b49fca51b1f5eef8ef8b95c3a43224a0eb2d
mariadb-columnstore-engine/dbcon/mysql/ha_mcs_pushdown.cpp
Gagan Goel 1c460f3ba5 MCOL-2178 Cleanup of MIGR:: singleton from the plugin code. 
Disable SP execution by the smart handlers for now.

    Add session variables to Enable/Disable select/derived/group_by
    handlers. Defaulted to Enable.
2019-08-04 21:50:50 -04:00

621 lines
19 KiB
C++
Raw Blame History

/*
Copyright (c) 2019 MariaDB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
// ha_calpont.cpp includes this file.
void mutate_optimizer_flags(THD *thd_)
{
// MCOL-2178 Disable all optimizer flags as it was in the fork.
// CS restores it later in SH::scan_end() and in case of an error
// in SH::scan_init()
set_original_optimizer_flags(thd_->variables.optimizer_switch, thd_);
thd_->variables.optimizer_switch = OPTIMIZER_SWITCH_IN_TO_EXISTS |
OPTIMIZER_SWITCH_EXISTS_TO_IN |
OPTIMIZER_SWITCH_COND_PUSHDOWN_FOR_DERIVED;
}
void restore_optimizer_flags(THD *thd_)
{
// MCOL-2178 restore original optimizer flags after SH, DH
ulonglong orig_flags = get_original_optimizer_flags(thd_);
if (orig_flags)
{
thd_->variables.optimizer_switch = orig_flags;
set_original_optimizer_flags(0, thd_);
}
}
/*@brief check_walk - It traverses filter conditions*/
/************************************************************
* DESCRIPTION:
* It traverses filter predicates looking for unsupported
* JOIN types: non-equi JOIN, e.g t1.c1 > t2.c2;
* logical OR.
* PARAMETERS:
* thd - THD pointer.
* derived - TABLE_LIST* to work with.
* RETURN:
* derived_handler if possible
* NULL in other case
***********************************************************/
void check_walk(const Item* item, void* arg)
{
bool* unsupported_feature = static_cast<bool*>(arg);
if ( *unsupported_feature )
return;
switch (item->type())
{
case Item::FUNC_ITEM:
{
const Item_func* ifp = static_cast<const Item_func*>(item);
if ( ifp->functype() != Item_func::EQ_FUNC ) // NON-equi JOIN
{
if ( ifp->argument_count() == 2 &&
ifp->arguments()[0]->type() == Item::FIELD_ITEM &&
ifp->arguments()[1]->type() == Item::FIELD_ITEM )
{
Item_field* left= static_cast<Item_field*>(ifp->arguments()[0]);
Item_field* right= static_cast<Item_field*>(ifp->arguments()[1]);
if ( left->field->table != right->field->table )
{
*unsupported_feature = true;
return;
}
}
else // IN + correlated subquery
{
if ( ifp->functype() == Item_func::NOT_FUNC
&& ifp->arguments()[0]->type() == Item::EXPR_CACHE_ITEM )
{
check_walk(ifp->arguments()[0], arg);
}
}
}
break;
}
case Item::EXPR_CACHE_ITEM: // IN + correlated subquery
{
const Item_cache_wrapper* icw = static_cast<const Item_cache_wrapper*>(item);
if ( icw->get_orig_item()->type() == Item::FUNC_ITEM )
{
const Item_func *ifp = static_cast<const Item_func*>(icw->get_orig_item());
if ( ifp->argument_count() == 2 &&
( ifp->arguments()[0]->type() == Item::Item::SUBSELECT_ITEM
|| ifp->arguments()[1]->type() == Item::Item::SUBSELECT_ITEM ))
{
*unsupported_feature = true;
return;
}
}
break;
}
case Item::COND_ITEM: // OR in JOIN conds is unsupported yet
{
Item_cond* icp = (Item_cond*)item;
if ( is_cond_or(icp) )
{
*unsupported_feature = true;
}
break;
}
default:
{
break;
}
}
}
/*@brief create_calpont_group_by_handler- Creates handler*/
/***********************************************************
* DESCRIPTION:
* Creates a group_by pushdown handler if there is no:
* non-equi JOIN, e.g * t1.c1 > t2.c2
* logical OR in the filter predicates
* Impossible WHERE
* Impossible HAVING
* and there is either GROUP BY or aggregation function
* exists at the top level.
* Valid queries with the last two crashes the server if
* processed.
* Details are in server/sql/group_by_handler.h
* PARAMETERS:
* thd - THD pointer
* query - Query structure LFM in group_by_handler.h
* RETURN:
* group_by_handler if success
* NULL in other case
***********************************************************/
static group_by_handler*
create_calpont_group_by_handler(THD* thd, Query* query)
{
ha_calpont_group_by_handler* handler = NULL;
// MCOL-2178 Disable SP support in the group_by_handler for now
// Check the session variable value to enable/disable use of
// group_by_handler
if (!get_group_by_handler(thd) || (thd->lex)->sphead)
{
return handler;
}
// same as thd->lex->current_select
SELECT_LEX *select_lex = query->from->select_lex;
// Create a handler if query is valid. See comments for details.
if ( query->group_by || select_lex->with_sum_func )
{
bool unsupported_feature = false;
// revisit SELECT_LEX for all units
for(TABLE_LIST* tl = query->from; !unsupported_feature && tl; tl = tl->next_global)
{
select_lex = tl->select_lex;
// Correlation subquery. Comming soon so fail on this yet.
unsupported_feature = select_lex->is_correlated;
// Impossible HAVING or WHERE
if ( ( !unsupported_feature && query->having && select_lex->having_value == Item::COND_FALSE )
|| ( select_lex->cond_count > 0
&& select_lex->cond_value == Item::COND_FALSE ) )
{
unsupported_feature = true;
}
// Unsupported JOIN conditions
if ( !unsupported_feature )
{
JOIN *join = select_lex->join;
Item_cond *icp = 0;
if (join != 0)
icp = reinterpret_cast<Item_cond*>(join->conds);
if ( unsupported_feature == false
&& icp )
{
icp->traverse_cond(check_walk, &unsupported_feature, Item::POSTFIX);
}
// Optimizer could move some join conditions into where
if (select_lex->where != 0)
icp = reinterpret_cast<Item_cond*>(select_lex->where);
if ( unsupported_feature == false
&& icp )
{
icp->traverse_cond(check_walk, &unsupported_feature, Item::POSTFIX);
}
}
} // unsupported features check ends here
if ( !unsupported_feature )
{
handler = new ha_calpont_group_by_handler(thd, query);
// Notify the server, that CS handles GROUP BY, ORDER BY and HAVING clauses.
query->group_by = NULL;
query->order_by = NULL;
query->having = NULL;
}
}
return handler;
}
/*@brief create_columnstore_derived_handler- Creates handler*/
/************************************************************
* DESCRIPTION:
* Creates a derived handler if there is no non-equi JOIN, e.g
* t1.c1 > t2.c2 and logical OR in the filter predicates.
* More details in server/sql/derived_handler.h
* PARAMETERS:
* thd - THD pointer.
* derived - TABLE_LIST* to work with.
* RETURN:
* derived_handler if possible
* NULL in other case
***********************************************************/
static derived_handler*
create_columnstore_derived_handler(THD* thd, TABLE_LIST *derived)
{
ha_columnstore_derived_handler* handler = NULL;
// MCOL-2178 Disable SP support in the derived_handler for now
// Check the session variable value to enable/disable use of
// derived_handler
if (!get_derived_handler(thd) || (thd->lex)->sphead)
{
return handler;
}
SELECT_LEX_UNIT *unit= derived->derived;
bool unsupported_feature = false;
{
SELECT_LEX select_lex = *unit->first_select();
JOIN* join = select_lex.join;
Item_cond* icp = 0;
if (join != 0)
icp = reinterpret_cast<Item_cond*>(join->conds);
if (!join)
{
icp = reinterpret_cast<Item_cond*>(select_lex.where);
}
if ( icp )
{
//icp->traverse_cond(check_walk, &unsupported_feature, Item::POSTFIX);
}
}
if ( !unsupported_feature )
handler= new ha_columnstore_derived_handler(thd, derived);
return handler;
}
/***********************************************************
* DESCRIPTION:
* derived_handler constructor
* PARAMETERS:
* thd - THD pointer.
* tbl - tables involved.
***********************************************************/
ha_columnstore_derived_handler::ha_columnstore_derived_handler(THD *thd,
TABLE_LIST *dt)
: derived_handler(thd, calpont_hton)
{
derived = dt;
}
/***********************************************************
* DESCRIPTION:
* derived_handler destructor
***********************************************************/
ha_columnstore_derived_handler::~ha_columnstore_derived_handler()
{}
/*@brief Initiate the query for derived_handler */
/***********************************************************
* DESCRIPTION:
* Execute the query and saves derived table query.
* PARAMETERS:
*
* RETURN:
* rc as int
***********************************************************/
int ha_columnstore_derived_handler::init_scan()
{
char query_buff[4096];
DBUG_ENTER("ha_columnstore_derived_handler::init_scan");
// Save query for logging
String derived_query(query_buff, sizeof(query_buff), thd->charset());
derived_query.length(0);
derived->derived->print(&derived_query, QT_ORDINARY);
mcs_handler_info mhi = mcs_handler_info(static_cast<void*>(this), DERIVED);
// this::table is the place for the result set
int rc = ha_cs_impl_pushdown_init(&mhi, table);
DBUG_RETURN(rc);
}
/*@brief Fetch next row for derived_handler */
/***********************************************************
* DESCRIPTION:
* Fetches next row and saves it in the temp table
* PARAMETERS:
*
* RETURN:
* rc as int
*
***********************************************************/
int ha_columnstore_derived_handler::next_row()
{
DBUG_ENTER("ha_columnstore_derived_handler::next_row");
int rc = ha_calpont_impl_rnd_next(table->record[0], table);
DBUG_RETURN(rc);
}
/*@brief Finishes the scan and clean it up */
/***********************************************************
* DESCRIPTION:
* Finishes the scan for derived handler
* PARAMETERS:
*
* RETURN:
* rc as int
*
***********************************************************/
int ha_columnstore_derived_handler::end_scan()
{
DBUG_ENTER("ha_columnstore_derived_handler::end_scan");
int rc = ha_calpont_impl_rnd_end(table, true);
DBUG_RETURN(rc);
}
void ha_columnstore_derived_handler::print_error(int, unsigned long)
{
}
/***********************************************************
* DESCRIPTION:
* GROUP BY handler constructor
* PARAMETERS:
* thd - THD pointer.
* query - Query describing structure
***********************************************************/
ha_calpont_group_by_handler::ha_calpont_group_by_handler(THD* thd_arg, Query* query)
: group_by_handler(thd_arg, calpont_hton),
select(query->select),
table_list(query->from),
distinct(query->distinct),
where(query->where),
group_by(query->group_by),
order_by(query->order_by),
having(query->having)
{
}
/***********************************************************
* DESCRIPTION:
* GROUP BY destructor
***********************************************************/
ha_calpont_group_by_handler::~ha_calpont_group_by_handler()
{
}
/***********************************************************
* DESCRIPTION:
* Makes the plan and prepares the data
* RETURN:
* int rc
***********************************************************/
int ha_calpont_group_by_handler::init_scan()
{
DBUG_ENTER("ha_calpont_group_by_handler::init_scan");
int rc = ha_calpont_impl_group_by_init(this, table);
DBUG_RETURN(rc);
}
/***********************************************************
* DESCRIPTION:
* Fetches a row and saves it to a temporary table.
* RETURN:
* int rc
***********************************************************/
int ha_calpont_group_by_handler::next_row()
{
DBUG_ENTER("ha_calpont_group_by_handler::next_row");
int rc = ha_calpont_impl_group_by_next(this, table);
DBUG_RETURN(rc);
}
/***********************************************************
* DESCRIPTION:
* Shuts the scan down.
* RETURN:
* int rc
***********************************************************/
int ha_calpont_group_by_handler::end_scan()
{
DBUG_ENTER("ha_calpont_group_by_handler::end_scan");
int rc = ha_calpont_impl_group_by_end(this, table);
DBUG_RETURN(rc);
}
/*@brief create_columnstore_select_handler- Creates handler*/
/************************************************************
* DESCRIPTION:
* Creates a select handler if there is no non-equi JOIN, e.g
* t1.c1 > t2.c2 and logical OR in the filter predicates.
* More details in server/sql/select_handler.h
* PARAMETERS:
* thd - THD pointer.
* sel - SELECT_LEX* that describes the query.
* RETURN:
* select_handler if possible
* NULL in other case
***********************************************************/
static select_handler*
create_columnstore_select_handler(THD* thd, SELECT_LEX* select_lex)
{
ha_columnstore_select_handler* handler = NULL;
// MCOL-2178 Disable SP support in the select_handler for now.
// Check the session variable value to enable/disable use of
// select_handler
if (!get_select_handler(thd) || (thd->lex)->sphead)
{
return handler;
}
bool unsupported_feature = false;
// Select_handler use the short-cut that effectively disables
// INSERT..SELECT and LDI
if ( (thd->lex)->sql_command == SQLCOM_INSERT_SELECT
|| (thd->lex)->sql_command == SQLCOM_CREATE_TABLE )
{
unsupported_feature = true;
}
// Impossible HAVING or WHERE
// WIP replace with function call
if ( unsupported_feature
|| ( select_lex->having && select_lex->having_value == Item::COND_FALSE )
|| ( select_lex->cond_count > 0
&& select_lex->cond_value == Item::COND_FALSE ) )
{
unsupported_feature = true;
}
// Unsupported query check.
if ( !unsupported_feature )
{
// JOIN expression from WHERE, ON expressions
JOIN* join = select_lex->join;
Item_cond* where_icp = 0;
Item_cond* on_icp = 0;
if (join != 0)
{
where_icp = reinterpret_cast<Item_cond*>(join->conds);
}
if ( where_icp )
{
//where_icp->traverse_cond(check_walk, &unsupported_feature, Item::POSTFIX);
}
// Looking for JOIN with ON expression through
// TABLE_LIST in FROM until CS meets unsupported feature
TABLE_LIST* table_ptr = select_lex->get_table_list();
for (; !unsupported_feature && table_ptr; table_ptr = table_ptr->next_global)
{
if(table_ptr->on_expr)
{
on_icp = reinterpret_cast<Item_cond*>(table_ptr->on_expr);
//on_icp->traverse_cond(check_walk, &unsupported_feature, Item::POSTFIX);
}
}
// CROSS JOIN w/o conditions isn't supported until MCOL-301
// is ready.
if (join && join->table_count >= 2 && ( !where_icp && !on_icp ))
{
unsupported_feature = true;
}
}
if (!unsupported_feature)
{
handler = new ha_columnstore_select_handler(thd, select_lex);
mutate_optimizer_flags(thd);
}
return handler;
}
/***********************************************************
* DESCRIPTION:
* select_handler constructor
* PARAMETERS:
* thd - THD pointer.
* select_lex - sematic tree for the query.
***********************************************************/
ha_columnstore_select_handler::ha_columnstore_select_handler(THD *thd,
SELECT_LEX* select_lex)
: select_handler(thd, calpont_hton)
{
select = select_lex;
}
/***********************************************************
* DESCRIPTION:
* select_handler constructor
***********************************************************/
ha_columnstore_select_handler::~ha_columnstore_select_handler()
{
}
/*@brief Initiate the query for select_handler */
/***********************************************************
* DESCRIPTION:
* Execute the query and saves select table query.
* PARAMETERS:
*
* RETURN:
* rc as int
***********************************************************/
int ha_columnstore_select_handler::init_scan()
{
char query_buff[4096];
DBUG_ENTER("ha_columnstore_select_handler::init_scan");
// Save query for logging
String select_query(query_buff, sizeof(query_buff), thd->charset());
select_query.length(0);
select->print(thd, &select_query, QT_ORDINARY);
mcs_handler_info mhi = mcs_handler_info(static_cast<void*>(this), SELECT);
// this::table is the place for the result set
int rc = ha_cs_impl_pushdown_init(&mhi, table);
DBUG_RETURN(rc);
}
/*@brief Fetch next row for select_handler */
/***********************************************************
* DESCRIPTION:
* Fetches next row and saves it in the temp table
* PARAMETERS:
*
* RETURN:
* rc as int
*
***********************************************************/
int ha_columnstore_select_handler::next_row()
{
DBUG_ENTER("ha_columnstore_select_handler::next_row");
int rc = ha_calpont_impl_rnd_next(table->record[0], table);
DBUG_RETURN(rc);
}
/*@brief Finishes the scan and clean it up */
/***********************************************************
* DESCRIPTION:
* Finishes the scan for select handler
* PARAMETERS:
*
* RETURN:
* rc as int
*
***********************************************************/
int ha_columnstore_select_handler::end_scan()
{
DBUG_ENTER("ha_columnstore_select_handler::end_scan");
int rc = ha_calpont_impl_rnd_end(table, true);
DBUG_RETURN(rc);
}
void ha_columnstore_select_handler::print_error(int, unsigned long)
{}
View Git Blame Copy Permalink