diff options
| -rw-r--r-- | sql/lex.h | 1 | ||||
| -rw-r--r-- | sql/records.cc | 37 | ||||
| -rw-r--r-- | sql/records.h | 1 | ||||
| -rw-r--r-- | sql/sql_yacc.yy | 15 | ||||
| -rw-r--r-- | sql/table.cc | 2 | ||||
| -rw-r--r-- | sql/table.h | 2 |
6 files changed, 53 insertions, 5 deletions
diff --git a/sql/lex.h b/sql/lex.h index 55589d888e6..b2ca572481d 100644 --- a/sql/lex.h +++ b/sql/lex.h @@ -571,6 +571,7 @@ SYMBOL symbols[] = { /** sql_function and condition_property_name for GET DIAGNOSTICS */ { "ROW_NUMBER", SYM(ROW_NUMBER_SYM)}, { "RTREE", SYM(RTREE_SYM)}, + {"SAMPLE_METHOD", SYM(SAMPLE_METHOD)}, { "SAVEPOINT", SYM(SAVEPOINT_SYM)}, { "SCHEDULE", SYM(SCHEDULE_SYM)}, { "SCHEMA", SYM(DATABASE)}, diff --git a/sql/records.cc b/sql/records.cc index 9eadf788585..896ecafe1c0 100644 --- a/sql/records.cc +++ b/sql/records.cc @@ -38,6 +38,7 @@ static int rr_quick(READ_RECORD *info); int rr_sequential(READ_RECORD *info); int rr_sequential_sample(READ_RECORD *info); +int rr_full_scan_sample(READ_RECORD *info); static int rr_from_tempfile(READ_RECORD *info); template<bool> static int rr_unpack_from_tempfile(READ_RECORD *info); template<bool,bool> static int rr_unpack_from_buffer(READ_RECORD *info); @@ -325,10 +326,26 @@ bool init_read_record(READ_RECORD *info,THD *thd, TABLE *table, else if (table->tablesample) { double fract= table->tablesample->val_real() / 100.0; + info->sample_factor = fract; info->sample_counter= (ha_rows)(table->file->records() * fract + 0.5); - info->read_record_func= rr_sequential_sample; - if (table->file->ha_sample_init()) - DBUG_RETURN(1); + if(table->sample_method_flag && table->sample_method_flag->val_real() > 1.0) + { + info->read_record_func= rr_full_scan_sample; + } + else + { + info->read_record_func= rr_sequential_sample; + } + if(table->sample_method_flag && table->sample_method_flag->val_real() > 1.0) + { + if (table->file->ha_rnd_init(TRUE)) + DBUG_RETURN(1); + } + else + { + if (table->file->ha_sample_init()) + DBUG_RETURN(1); + } } else { @@ -548,6 +565,20 @@ int rr_sequential_sample(READ_RECORD *info) return tmp; } +int rr_full_scan_sample(READ_RECORD *info) +{ + int tmp; + do + { + tmp= info->table->file->ha_rnd_next(info->record()); + if(thd_rnd(info->thd) <= info->sample_factor) + break; + } while (!tmp); + if(tmp) + tmp= rr_handle_error(info, tmp); + return tmp; +} + static int rr_from_tempfile(READ_RECORD *info) { diff --git a/sql/records.h b/sql/records.h index 579e0e2bf3a..ed3b9a84b5a 100644 --- a/sql/records.h +++ b/sql/records.h @@ -62,6 +62,7 @@ struct READ_RECORD uint ref_length, reclength, rec_cache_size, error_offset; ha_rows sample_counter; + double sample_factor; /** Counting records when reading result from filesort(). Used when filesort leaves the result in the filesort buffer. diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy index 88df2bc3d7a..0399225ad5f 100644 --- a/sql/sql_yacc.yy +++ b/sql/sql_yacc.yy @@ -679,6 +679,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize); %token <kwd> SYSDATE %token <kwd> TABLE_REF_PRIORITY %token <kwd> TABLESAMPLE /* SQL-2016-R */ +%token <kwd> SAMPLE_METHOD %token <kwd> TABLE_SYM /* SQL-2003-R */ %token <kwd> TERMINATED %token <kwd> THEN_SYM /* SQL-2003-R */ @@ -1499,7 +1500,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize); %type <item_param> param_marker %type <item_num> - NUM_literal opt_table_sample + NUM_literal opt_table_sample opt_sample_method %type <item_basic_constant> text_literal @@ -11710,10 +11711,18 @@ opt_table_sample: } ; +opt_sample_method: + /* empty */ { $$=0; } + | SAMPLE_METHOD '(' NUM_literal ')' + { + $$=$3; + } + ; + table_primary_ident: table_ident opt_use_partition opt_for_system_time_clause opt_table_alias_clause opt_key_definition - opt_table_sample + opt_table_sample opt_sample_method { if (!($$= Select->add_table_to_list(thd, $1, $4, 0, @@ -11726,6 +11735,8 @@ table_primary_ident: $$->vers_conditions= Lex->vers_conditions; if ($6) $$->tablesample= $6; + if ($7) + $$->sample_method_flag= $7; } ; diff --git a/sql/table.cc b/sql/table.cc index 4504e37dd7f..795a9e0b754 100644 --- a/sql/table.cc +++ b/sql/table.cc @@ -5555,6 +5555,7 @@ void TABLE::init(THD *thd, TABLE_LIST *tl) no_cache= false; initialize_opt_range_structures(); tablesample= NULL; + sample_method_flag= NULL; #ifdef HAVE_REPLICATION /* used in RBR Triggers */ master_had_triggers= 0; @@ -8546,6 +8547,7 @@ bool TABLE_LIST::process_table_sample(TABLE *tbl) tbl->keys_in_use_for_order_by.clear_all(); tbl->covering_keys.clear_all(); tbl->tablesample= tablesample; + tbl->sample_method_flag= sample_method_flag; } return false; } diff --git a/sql/table.h b/sql/table.h index 5c0e7f9b51a..266249fd9aa 100644 --- a/sql/table.h +++ b/sql/table.h @@ -1498,6 +1498,7 @@ public: bool master_had_triggers; #endif Item *tablesample; + Item *sample_method_flag; /* rand_sample if>=1.0, full_scan_sample another*/ REGINFO reginfo; /* field connections */ MEM_ROOT mem_root; /** @@ -2223,6 +2224,7 @@ struct TABLE_LIST for_insert_data= insert_data; } Item *tablesample; + Item *sample_method_flag; /* List of tables local to a subquery (used by SQL_I_List). Considers |