在Oracle世界里，索引主要有B树索引，位图索引和全文索引等，其中最常见于OLTP系统的是B树索引，位图索引和全文索引则多用于OLAP系统中；索引就类似于一本书的目录，若只想了解某个章节，则在不需要通读全书，可以通过索引迅速的找到需要的内容；若需要通读全书，恐怕没有人会看一页文章内容，再回头看下目录这样阅读吧，这2次I/O，必然浪费时间和资源；B树索引比较适合值分布比较均匀的场合，因而普遍用于OLTP系统中；位图索引则适用于取值范围相对较小，且更改频率低的场合，相比B树索引，位图索引将占用更少的存储空间；全文索引则类似分词系统，一般用在CLOB字段或者TEXT字段上，全文索引会占用很大的储存空间，有可能索引的大小要远大于基表本身;索引会随着基表的更改而被oracle自动维护！下面就来简要的谈谈B树索引！
一：下列几种情况将不使用索引
1：使用不等于操作符
SQL> create table t1 as select * from dba_source;
Table created.
SQL> create index ind_t1 on t1(name);
Index created.
SQL> set autot trace exp stat
SQL> select * from t1 where name <> 'STANDARD';
634915 rows selected.
Execution Plan
----------------------------------------------------------
Plan hash value: 3617692013
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 565K| 1108M| 2948 (1)| 00:00:36 |
|* 1 | TABLE ACCESS FULL| T1 | 565K| 1108M| 2948 (1)| 00:00:36 |
--------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter("NAME"<>'STANDARD')
Note
-----
- dynamic sampling used for this statement (level=2)
Statistics
----------------------------------------------------------
10 recursive calls
0 db block gets
52377 consistent gets
10977 physical reads
0 redo size
52132322 bytes sent via SQL*Net to client
466016 bytes received via SQL*Net from client
42329 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
634915 rows processed
2: 使用IS NULL或者IS NOT NULL
SQL> exec dbms_stats.gather_table_stats('HR','T1',cascade=>true);
PL/SQL procedure successfully completed.
SQL> select * from t1 where name is null;
no rows selected
Execution Plan
----------------------------------------------------------
Plan hash value: 3617692013
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 100 | 2947 (1)| 00:00:36 |
|* 1 | TABLE ACCESS FULL| T1 | 1 | 100 | 2947 (1)| 00:00:36 |
--------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter("NAME" IS NULL)
Statistics
----------------------------------------------------------
1 recursive calls
0 db block gets
10709 consistent gets
10706 physical reads
0 redo size
517 bytes sent via SQL*Net to client
408 bytes received via SQL*Net from client
1 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
0 rows processed
3：不使用基于函数的索引条件下，使用函数
SQL> select * from t1 where lower(name)='standard';
3966 rows selected.
Execution Plan
----------------------------------------------------------
Plan hash value: 3617692013
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 6389 | 623K| 2950 (1)| 00:00:36 |
|* 1 | TABLE ACCESS FULL| T1 | 6389 | 623K| 2950 (1)| 00:00:36 |
--------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter(LOWER("NAME")='standard')
Statistics
----------------------------------------------------------
1 recursive calls
0 db block gets
10968 consistent gets
10706 physical reads
0 redo size
237461 bytes sent via SQL*Net to client
3323 bytes received via SQL*Net from client
266 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
3966 rows processed
4：比较不匹配的数据类型
SQL> create table t2 (id varchar2(10),name varchar2(10));
Table created.
SQL> begin
2 for i in 1..100000
3 loop
4 insert into t2 values (i,'t2');
5 end loop;
6 commit;
7 end;
8 /
PL/SQL procedure successfully completed.
SQL> create index ind_t2 on t2(id);
Index created.
SQL> exec dbms_stats.gather_table_stats('HR','T2',cascade=>true);
PL/SQL procedure successfully completed.
SQL> select * from t2 where id=100;
Execution Plan
----------------------------------------------------------
Plan hash value: 1513984157
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 9 | 69 (2)| 00:00:01 |
|* 1 | TABLE ACCESS FULL| T2 | 1 | 9 | 69 (2)| 00:00:01 |
--------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter(TO_NUMBER("ID")=100)
Statistics
----------------------------------------------------------
1 recursive calls
1 db block gets
255 consistent gets
0 physical reads
0 redo size
478 bytes sent via SQL*Net to client
419 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
1 rows processed
二：使用B树索引
1:新建2张表，并分别对name字段创建索引，收集表统计信息；t2表的name字段为倾斜型，t1表则相对比较均匀；
SQL> grant select_catalog_role to sale;
Grant succeeded.
SQL> conn sale/123456
Connected.
SQL> create table t1 as select * from dba_source;
Table created.
SQL> create table t2 as select * from dba_source;
Table created.
SQL> update t2 set name='SALE';
292436 rows updated.
SQL> commit;
Commit complete.
SQL> update t2 set name='T2' where rownum < 2;
1 row updated.
SQL> commit;
Commit complete.
SQL> create index ind_t1 on t1(name);
Index created.
SQL> create index ind_t2 on t2(name);
Index created.
SQL> exec dbms_stats.gather_table_stats('sale','t1',cascade=>true);
PL/SQL procedure successfully completed.
SQL> exec dbms_stats.gather_table_stats('sale','t2',cascade=>true);
PL/SQL procedure successfully completed.
2：对t1表进行查询，可以看到，查询1使用索引ind_t1,查询2根据hint提示使用全表扫描，对比两次查询的CPU代价和一致性读，可以看出索引的优势！
SQL> set autot trace exp stat
SQL> select * from t1 where name='STANDARD';
3933 rows selected.
Execution Plan
----------------------------------------------------------
Plan hash value: 634656657
--------------------------------------------------------------------------------
------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time
|
--------------------------------------------------------------------------------
------
| 0 | SELECT STATEMENT | | 476 | 55692 | 18 (0)| 00:0
0:01 |
| 1 | TABLE ACCESS BY INDEX ROWID| T1 | 476 | 55692 | 18 (0)| 00:0
0:01 |
|* 2 | INDEX RANGE SCAN | IND_T1 | 476 | | 4 (0)| 00:0
0:01 |
--------------------------------------------------------------------------------
------
Predicate Information (identified by operation id):
---------------------------------------------------
2 - access("NAME"='STANDARD')
Statistics
----------------------------------------------------------
0 recursive calls
0 db block gets
575 consistent gets
0 physical reads
0 redo size
336844 bytes sent via SQL*Net to client
3351 bytes received via SQL*Net from client
264 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
3933 rows processed
SQL> select /*+full(t1)*/ * from t1 where name='STANDARD';
3933 rows selected.
Execution Plan
----------------------------------------------------------
Plan hash value: 3617692013
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 476 | 55692 | 1389 (1)| 00:00:17 |
|* 1 | TABLE ACCESS FULL| T1 | 476 | 55692 | 1389 (1)| 00:00:17 |
--------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter("NAME"='STANDARD')
Statistics
----------------------------------------------------------
802 recursive calls
0 db block gets
6580 consistent gets
6134 physical reads
0 redo size
250150 bytes sent via SQL*Net to client
3351 bytes received via SQL*Net from client
264 SQL*Net roundtrips to/from client
20 sorts (memory)
0 sorts (disk)
3933 rows processed
3：对t2表进行查询，可以看到，查询1使用索引ind_t2,查询2则使用全表扫描，因为name字段基于所以的值均为SALE，所以这个时候使用全表扫描反而更快，查询3使用hint提示使用ind_t2索引，将产生更大的开销，由此可见，B树索引适合于值分布比较均匀的场合,否则2次I/O将导致查询更慢！
SQL> set autot trace exp stat
SQL> select * from t2 where name='T2';
Execution Plan
----------------------------------------------------------
Plan hash value: 591771271
--------------------------------------------------------------------------------
------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time
|
--------------------------------------------------------------------------------
------
| 0 | SELECT STATEMENT | | 1 | 107 | 4 (0)| 00:0
0:01 |
| 1 | TABLE ACCESS BY INDEX ROWID| T2 | 1 | 107 | 4 (0)| 00:0
0:01 |
|* 2 | INDEX RANGE SCAN | IND_T2 | 1 | | 3 (0)| 00:0
0:01 |
--------------------------------------------------------------------------------
------
Predicate Information (identified by operation id):
---------------------------------------------------
2 - access("NAME"='T2')
Statistics
----------------------------------------------------------
183 recursive calls
0 db block gets
28 consistent gets
4 physical reads
0 redo size
875 bytes sent via SQL*Net to client
469 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
5 sorts (memory)
0 sorts (disk)
1 rows processed
SQL> select * from t2 where name='SALE';
292435 rows selected.
Execution Plan
----------------------------------------------------------
Plan hash value: 1513984157
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 291K| 29M| 1391 (2)| 00:00:17 |
|* 1 | TABLE ACCESS FULL| T2 | 291K| 29M| 1391 (2)| 00:00:17 |
--------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter("NAME"='SALE')
Statistics
----------------------------------------------------------
1 recursive calls
0 db block gets
25293 consistent gets
605 physical reads
0 redo size
30733266 bytes sent via SQL*Net to client
214914 bytes received via SQL*Net from client
19497 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
292435 rows processed
SQL> select /*+index(t2 ind_t2)*/ * from t2 where name='SALE';
292435 rows selected.
Execution Plan
----------------------------------------------------------
Plan hash value: 591771271
--------------------------------------------------------------------------------
------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time
|
--------------------------------------------------------------------------------
------
| 0 | SELECT STATEMENT | | 291K| 29M| 6850 (1)| 00:0
1:23 |
| 1 | TABLE ACCESS BY INDEX ROWID| T2 | 291K| 29M| 6850 (1)| 00:0
1:23 |
|* 2 | INDEX RANGE SCAN | IND_T2 | 292K| | 662 (2)| 00:0
0:08 |
--------------------------------------------------------------------------------
------
Predicate Information (identified by operation id):
---------------------------------------------------
2 - access("NAME"='SALE')
Statistics
----------------------------------------------------------
1 recursive calls
0 db block gets
45391 consistent gets
2454 physical reads
0 redo size
36955099 bytes sent via SQL*Net to client
214914 bytes received via SQL*Net from client
19497 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
292435 rows processed
三：表和索引的压缩,在大数据量条件下，除了使用分区技术来裁剪I/O外，压缩也是个不错的选择，但压缩比较适合于更新不频繁的场景
1：查看T1表和IND_T1索引的DDL创建语句和存储占用情况
SQL> show user;
USER is "SYS"
SQL> set long 5000
SQL> set heading off
SQL> select dbms_metadata.get_ddl('TABLE', 'T1', 'SALE') from dual;
CREATE TABLE "SALE"."T1"
( "OWNER" VARCHAR2(30),
"NAME" VARCHAR2(30),
"TYPE" VARCHAR2(12),
"LINE" NUMBER,
"TEXT" VARCHAR2(4000)
) PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 NOCOMP
RESS LOGGING
STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS
1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_PO
OL DEFAULT)
TABLESPACE "USERS"
SQL> select dbms_metadata.get_ddl('INDEX', 'IND_T1', 'SALE') from dual;
CREATE INDEX "SALE"."IND_T1" ON "SALE"."T1" ("NAME")
PCTFREE 10 INITRANS 2 MAXTRANS 255 COMPUT
E STATISTICS
STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENT
S 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_P
OOL DEFAULT)
TABLESPACE "USERS"
SQL> desc show_space;
PROCEDURE show_space
Argument Name Type In/Out Default?
------------------------------ ----------------------- ------ --------
P_SEGNAME VARCHAR2 IN
P_OWNER VARCHAR2 IN DEFAULT
P_TYPE VARCHAR2 IN DEFAULT
P_PARTITION VARCHAR2 IN DEFAULT
SQL> set serveroutput on
SQL> exec show_space('T1','SALE','table');
Free Blocks.............................
Total Blocks............................6400
Total Bytes.............................52428800
Total MBytes............................50
Unused Blocks...........................118
Unused Bytes............................966656
Last Used Ext FileId....................4
Last Used Ext BlockId...................6665
Last Used Block.........................10
PL/SQL procedure successfully completed.
SQL> exec show_space('IND_T1','SALE','index');
Free Blocks.............................
Total Blocks............................1152
Total Bytes.............................9437184
Total MBytes............................9
Unused Blocks...........................114
Unused Bytes............................933888
Last Used Ext FileId....................4
Last Used Ext BlockId...................14217
Last Used Block.........................14
PL/SQL procedure successfully completed.
2：新建表t3和索引ind_t3，带压缩属性,对比表t1所占的存储，表为50M:37M，索引为9M:4M
SQL> create table t3 compress as select * from t1;
Table created.
SQL> select table_name,compression from user_tables where table_name like 'T%';
TABLE_NAME COMPRESS
------------------------------ --------
T3 ENABLED
T2 DISABLED
T1 DISABLED
SQL> exec show_space('T3','SALE','table');
Free Blocks.............................
Total Blocks............................4736
Total Bytes.............................38797312
Total MBytes............................37
Unused Blocks...........................70
Unused Bytes............................573440
Last Used Ext FileId....................4
Last Used Ext BlockId...................19849
Last Used Block.........................58
PL/SQL procedure successfully completed.
SQL> create index ind_t3 on t3(name) compress;
Index created.
SQL> select table_name,compression from user_indexes where table_name like 'T%';
TABLE_NAME COMPRESS
------------------------------ --------
T3 ENABLED
T2 DISABLED
T1 DISABLED
SQL> exec show_space('IND_T3','SALE','index');
Free Blocks.............................
Total Blocks............................512
Total Bytes.............................4194304
Total MBytes............................4
Unused Blocks...........................32
Unused Bytes............................262144
Last Used Ext FileId....................4
Last Used Ext BlockId...................20361
Last Used Block.........................96
PL/SQL procedure successfully completed.
3：分区表的本地索引压缩，需要先在对象级别上启用压缩
SQL> select table_name from user_part_tables;
TABLE_NAME
------------------------------
SALE_DATA
EMP
SQL> select index_name from user_part_indexes where table_name in (select table_name from user_part_tables);
INDEX_NAME
------------------------------
IND_SALE_DATA_DATE
SQL> select partition_name,tablespace_name,compression from user_ind_partitions where
index_name='IND_SALE_DATA_DATE';
PARTITION_NAME TABLESPACE_NAME COMPRESS
------------------------------ ------------------------------ --------
SALES_01 TBS_SALE01 DISABLED
SALES_02 TBS_SALE02 DISABLED
SALES_03 TBS_SALE03 DISABLED
SALES_04 TBS_SALE04 DISABLED
SALES_05 TBS_SALE05 DISABLED
SALES_06 TBS_SALE06 DISABLED
SALES_07 TBS_SALE07 DISABLED
SALES_08 TBS_SALE08 DISABLED
SALES_09 TBS_SALE09 DISABLED
SALES_10 TBS_SALE10 DISABLED
SALES_11 TBS_SALE11 DISABLED
PARTITION_NAME TABLESPACE_NAME COMPRESS
------------------------------ ------------------------------ --------
SALES_12 TBS_SALE12 DISABLED
SQL> alter index IND_SALE_DATA_DATE modify partition sales_01 compress;
alter index IND_SALE_DATA_DATE modify partition sales_01 compress
*
ERROR at line 1:
ORA-28659: COMPRESS must be specified at object level first
SQL> drop index IND_SALE_DATA_DATE;
Index dropped.
SQL> create index ind_sale_data_date on sale_data(sale_id) local compress;
Index created.
SQL> select partition_name,tablespace_name,compression from user_ind_partitions where
index_name='IND_SALE_DATA_DATE';
PARTITION_NAME TABLESPACE_NAME COMPRESS
------------------------------ ------------------------------ --------
SALES_01 TBS_SALE01 ENABLED
SALES_02 TBS_SALE02 ENABLED
SALES_03 TBS_SALE03 ENABLED
SALES_04 TBS_SALE04 ENABLED
SALES_05 TBS_SALE05 ENABLED
SALES_06 TBS_SALE06 ENABLED
SALES_07 TBS_SALE07 ENABLED
SALES_08 TBS_SALE08 ENABLED
SALES_09 TBS_SALE09 ENABLED
SALES_10 TBS_SALE10 ENABLED
SALES_11 TBS_SALE11 ENABLED
PARTITION_NAME TABLESPACE_NAME COMPRESS
------------------------------ ------------------------------ --------
SALES_12 TBS_SALE12 ENABLED
SQL> alter index ind_sale_data_date modify partition sales_01 nocompress;
Index altered.
SQL> alter index ind_sale_data_date rebuild partition sales_02 nocompress;
Index altered.
SQL> select partition_name,tablespace_name,compression from user_ind_partitions where
index_name='IND_SALE_DATA_DATE';
PARTITION_NAME TABLESPACE_NAME COMPRESS
------------------------------ ------------------------------ --------
SALES_01 TBS_SALE01 DISABLED
SALES_02 TBS_SALE02 DISABLED
SALES_03 TBS_SALE03 ENABLED
SALES_04 TBS_SALE04 ENABLED
SALES_05 TBS_SALE05 ENABLED
SALES_06 TBS_SALE06 ENABLED
SALES_07 TBS_SALE07 ENABLED
SALES_08 TBS_SALE08 ENABLED
SALES_09 TBS_SALE09 ENABLED
SALES_10 TBS_SALE10 ENABLED
SALES_11 TBS_SALE11 ENABLED
PARTITION_NAME TABLESPACE_NAME COMPRESS
------------------------------ ------------------------------ --------
SALES_12 TBS_SALE12 ENABLED
四：对象分析与执行计划,oracle 10g以后关于sql语句的执行，默认都是使用cbo，即基于代价的优化器，而不是基于规则的，这个代价则是有对象分析而来，也就是我们平常说的统计信息，下面来看下当统计信息未及时更新的情况下，sql执行计划的选择！
1：创建基表和索引，可以看到，当没有统计信息的时候，oracle将采取动态采样方式，也可以获得正确的执行计划
SQL> create table t4 as select 100 object_id,object_name from dba_objects;
Table created.
SQL> update t4 set object_id=1 where rownum=1;
1 row updated.
SQL> commit;
Commit complete
SQL> create index ind_t4 on t4(object_id);
Index created.
SQL> set autot trace exp stat
SQL> select * from t4 where object_id=100;
50414 rows selected.
Execution Plan
----------------------------------------------------------
Plan hash value: 2560505625
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 54273 | 4187K| 56 (4)| 00:00:01 |
|* 1 | TABLE ACCESS FULL| T4 | 54273 | 4187K| 56 (4)| 00:00:01 |
--------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter("OBJECT_ID"=100)
Note
-----
- dynamic sampling used for this statement
Statistics
----------------------------------------------------------
52 recursive calls
0 db block gets
3658 consistent gets
5 physical reads
0 redo size
1691795 bytes sent via SQL*Net to client
37429 bytes received via SQL*Net from client
3362 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
50414 rows processed
SQL> select * from t4 where object_id=1;
Execution Plan
----------------------------------------------------------
Plan hash value: 4096627024
--------------------------------------------------------------------------------
------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time
|
--------------------------------------------------------------------------------
------
| 0 | SELECT STATEMENT | | 1 | 79 | 2 (0)| 00:0
0:01 |
| 1 | TABLE ACCESS BY INDEX ROWID| T4 | 1 | 79 | 2 (0)| 00:0
0:01 |
|* 2 | INDEX RANGE SCAN | IND_T4 | 1 | | 1 (0)| 00:0
0:01 |
--------------------------------------------------------------------------------
------
Predicate Information (identified by operation id):
---------------------------------------------------
2 - access("OBJECT_ID"=1)
Note
-----
- dynamic sampling used for this statement
Statistics
----------------------------------------------------------
7 recursive calls
0 db block gets
76 consistent gets
0 physical reads
0 redo size
595 bytes sent via SQL*Net to client
469 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
1 rows processed
2：删除表中所有的数据后，收集统计信息，然后再插入原先一样的数据
SQL> delete from t4;
50415 rows deleted.
SQL> exec dbms_stats.gather_table_stats('sale','t4',cascade=>true);
PL/SQL procedure successfully completed.
SQL> insert into t4 select 100 object_id,object_name from dba_objects;
50416 rows created.
SQL> update t4 set object_id=1 where rownum=1;
1 row updated.
SQL> commit
Commit complete.
SQL> select object_id,count(*) from t4 group by object_id;
OBJECT_ID COUNT(*)
---------- ----------
1 1
100 50415
3：这个时候，统计信息未及时更新，认为下面的查询语句选择走索引会更优，则会产生错误的执行计划，导致查询语句缓慢！在生产环境，大数据量情况下尤为明显！
SQL> set autot trace exp stat
SQL> select * from t4 where object_id=100;
50415 rows selected.
Execution Plan
----------------------------------------------------------
Plan hash value: 4096627024
--------------------------------------------------------------------------------
------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time
|
--------------------------------------------------------------------------------
------
| 0 | SELECT STATEMENT | | 1 | 79 | 1 (0)| 00:0
0:01 |
| 1 | TABLE ACCESS BY INDEX ROWID| T4 | 1 | 79 | 1 (0)| 00:0
0:01 |
|* 2 | INDEX RANGE SCAN | IND_T4 | 1 | | 1 (0)| 00:0
0:01 |
--------------------------------------------------------------------------------
------
Predicate Information (identified by operation id):
---------------------------------------------------
2 - access("OBJECT_ID"=100)
Statistics
----------------------------------------------------------
0 recursive calls
0 db block gets
3581 consistent gets
0 physical reads
0 redo size
1692701 bytes sent via SQL*Net to client
37429 bytes received via SQL*Net from client
3362 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
50415 rows processed
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