bitmap join indexIn-memory big data OLAP (on-line analytical processing) is time consuming task for data access latency and complex star join processing overhead. GPU is introduced to DBMSs for its remarkable parallel computing power but also restricted by its limited GPU memory size and low ...
DBMS_SPACE.CREATE_INDEX_COST ( ddl IN VARCHAR2, used_bytes OUT NUMBER, alloc_bytes OUT NUMBER, plan_table IN VARCHAR2 DEFAULT NULL); 1. 2. 3. 4. 5. Usage Notes The table on which the index is created must already exist. The computation of the index size depends on statistics gather...
SQL> create bitmap index bm_random on emp_random(empno); 索引已创建。 SQL> analyze table emp_random compute statistics for table for all indexes for all columns; 表已分析。 SQL> select index_name,clustering_factor from user_indexes; INDEX_NAME CLUSTERING_FACTOR --- --- BM_RANDOM 1000000 ...
The key idea consists in constructing a decision tree, within the DBMS , using bitmap indices. Indeed bitmap indices have many useful properties such as the count and bit-wise operations. We will show that these operations are efficient to build decision trees. In addition, by using bitmap ...
Index created. SQL> create index ind_t2 on t2(object_id); Index created. 收集统计信息: BEGIN DBMS_STATS.GATHER_TABLE_STATS(ownname => 'scott', tabname => 't1', estimate_percent =>100, method_opt => 'for all columns size 1', ...
SQL>createindexb_tree_t_xifenfeiont_xifenfei(object_id); Indexcreated. SQL>CREATEBITMAPINDEXbitmap_t_xifenfeiont_xifenfei(object_name); Indexcreated. SQL>BEGIN 2 dbms_stats.gather_table_stats(USER,'T_XIFENFEI',cascade=>true); 3END; ...
Create table test_normal (empno number(10), ename varchar2(30), sal number(10)); Begin For i in 1..1000000 Loop Insert into test_normal values(i, dbms_random.string('U',30), dbms_random.value(1000,7000)); If mod(i, 10000) = 0 then Commit; End if; End loop; End; / Create...
[8]. More recently, various DBMS vendors, including Oracle, Red- Brick, and Sybase, have introduced bitmap indexes into their prod- ucts to meet the performance requirements of DSS applications [5, 6]. In its simplest form, a bitmap index on an indexed attribute ...
By introducing a manual unnest in the original client code I avoided the bitmap conversion to rowid, and the query executed much more efficiently. As you can see the optimizer has predicted the 1M rowids in the inline view, but used only the key values from the 600 index entries. In the...
“Unable to enlist in the transaction” with Oracle linked server from MS SQL Server [<Name of Missing Index, sysname,>] in non clustered index [Execute SQL Task] Error: The value type (__ComObject) can only be converted to variables of type Object. [ODBC Driver Manager] Data source...