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0.1: SQL-level System Versioning

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This commit is contained in:
Daniel Fiala
2016-06-19 07:38:28 +01:00
committed by Aleksey Midenkov
parent 14bdfa8541
commit be6f2d302c
115 changed files with 4055 additions and 1101 deletions
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113
sql/sql_select.cc
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@ -588,7 +588,7 @@ void remove_redundant_subquery_clauses(st_select_lex *subq_select_lex)
subq_select_lex->group_list.empty();
DBUG_PRINT("info", ("GROUP BY removed"));
}
/*
TODO: This would prevent processing quries with ORDER BY ... LIMIT
therefore we disable this optimization for now.
@ -666,6 +666,77 @@ setup_without_group(THD *thd, Ref_ptr_array ref_pointer_array,
DBUG_RETURN(res);
}
static int
setup_for_system_time(THD *thd, TABLE_LIST *tables, COND **conds, SELECT_LEX *select_lex)
{
DBUG_ENTER("setup_for_system_time");
TABLE_LIST *table;
int versioned_tables= 0;
for (table= tables; table; table= table->next_local)
{
if (table->table && table->table->versioned())
versioned_tables++;
else if (table->system_versioning.type != FOR_SYSTEM_TIME_UNSPECIFIED)
{
my_error(ER_TABLE_DOESNT_SUPPORT_SYSTEM_VERSIONING, MYF(0), table->table_name);
DBUG_RETURN(-1);
}
}
if (versioned_tables == 0)
DBUG_RETURN(0);
for (table= tables; table; table= table->next_local)
{
if (table->table && table->table->versioned())
{
Field *fstart= table->table->vers_start_field();
Field *fend= table->table->vers_end_field();
Item *istart= new (thd->mem_root) Item_field(thd, fstart);
Item *iend= new (thd->mem_root) Item_field(thd, fend);
Item *cond1= 0, *cond2= 0, *curr = 0;
switch (table->system_versioning.type)
{
case FOR_SYSTEM_TIME_UNSPECIFIED:
curr= new (thd->mem_root) Item_func_now_local(thd, 6);
cond1= new (thd->mem_root) Item_func_le(thd, istart, curr);
cond2= new (thd->mem_root) Item_func_gt(thd, iend, curr);
break;
case FOR_SYSTEM_TIME_AS_OF:
cond1= new (thd->mem_root) Item_func_le(thd, istart,
table->system_versioning.start);
cond2= new (thd->mem_root) Item_func_gt(thd, iend,
table->system_versioning.start);
break;
case FOR_SYSTEM_TIME_FROM_TO:
cond1= new (thd->mem_root) Item_func_lt(thd, istart,
table->system_versioning.end);
cond2= new (thd->mem_root) Item_func_ge(thd, iend,
table->system_versioning.start);
break;
case FOR_SYSTEM_TIME_BETWEEN:
cond1= new (thd->mem_root) Item_func_le(thd, istart,
table->system_versioning.end);
cond2= new (thd->mem_root) Item_func_ge(thd, iend,
table->system_versioning.start);
break;
default:
DBUG_ASSERT(0);
}
if (cond1 && cond2)
{
COND *system_time_cond= new (thd->mem_root) Item_cond_and(thd, cond1, cond2);
thd->change_item_tree(conds, and_items(thd, *conds, system_time_cond));
table->system_versioning.is_moved_to_where= true;
}
}
}
DBUG_RETURN(0);
}
/*****************************************************************************
Check fields, find best join, do the select and output fields.
mysql_select assumes that all tables are already opened
@ -740,7 +811,11 @@ JOIN::prepare(TABLE_LIST *tables_init,
{
remove_redundant_subquery_clauses(select_lex);
}
/* Handle FOR SYSTEM_TIME clause. */
if (setup_for_system_time(thd, tables_list, &conds, select_lex) < 0)
DBUG_RETURN(-1);
/*
TRUE if the SELECT list mixes elements with and without grouping,
and there is no GROUP BY clause. Mixing non-aggregated fields with
@ -24784,6 +24859,38 @@ bool mysql_explain_union(THD *thd, SELECT_LEX_UNIT *unit, select_result *result)
DBUG_RETURN(res || thd->is_error());
}
void TABLE_LIST::print_system_versioning(THD *thd, table_map eliminated_tables,
String *str, enum_query_type query_type)
{
if (system_versioning.is_moved_to_where)
return;
// system versioning
if (system_versioning.type != FOR_SYSTEM_TIME_UNSPECIFIED)
{
switch (system_versioning.type)
{
case FOR_SYSTEM_TIME_AS_OF:
str->append(STRING_WITH_LEN(" for system_time as of "));
system_versioning.start->print(str, query_type);
break;
case FOR_SYSTEM_TIME_FROM_TO:
str->append(STRING_WITH_LEN(" for system_time from timestamp "));
system_versioning.start->print(str, query_type);
str->append(STRING_WITH_LEN(" to "));
system_versioning.end->print(str, query_type);
break;
case FOR_SYSTEM_TIME_BETWEEN:
str->append(STRING_WITH_LEN(" for system_time between timestamp "));
system_versioning.start->print(str, query_type);
str->append(STRING_WITH_LEN(" and "));
system_versioning.end->print(str, query_type);
break;
default:
DBUG_ASSERT(0);
}
}
}
static void print_table_array(THD *thd,
table_map eliminated_tables,
@ -25119,6 +25226,8 @@ void TABLE_LIST::print(THD *thd, table_map eliminated_tables, String *str,
append_identifier(thd, str, t_alias, strlen(t_alias));
}
print_system_versioning(thd, eliminated_tables, str, query_type);
if (index_hints)
{
List_iterator<Index_hint> it(*index_hints);