recyclebin$里表太多引发的问题
检查表空间的时候，执行检查表空间的语句发现特别慢，于是做了一个执行计划看看。
执行计划如下：
[sql]
----------------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
----------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 6 | 540 | 386K(100)| 01:17:24 |
| 1 | SORT ORDER BY | | 6 | 540 | 386K(100)| 01:17:24 |
|* 2 | HASH JOIN | | 6 | 540 | 386K(100)| 01:17:24 |
| 3 | VIEW | | 2 | 60 | 5 (20)| 00:00:01 |
| 4 | HASH GROUP BY | | 2 | 294 | 5 (20)| 00:00:01 |
| 5 | VIEW | DBA_DATA_FILES | 2 | 294 | 4 (0)| 00:00:01 |
| 6 | UNION-ALL | | | | | |
| 7 | NESTED LOOPS | | 1 | 222 | 2 (0)| 00:00:01 |
| 8 | NESTED LOOPS | | 1 | 209 | 1 (0)| 00:00:01 |
| 9 | NESTED LOOPS | | 1 | 196 | 1 (0)| 00:00:01 |
|* 10 | FIXED TABLE FULL | X$KCCFN | 1 | 182 | 0 (0)| 00:00:01 |
|* 11 | TABLE ACCESS BY INDEX ROWID | FILE$ | 1 | 14 | 1 (0)| 00:00:01 |
|* 12 | INDEX UNIQUE SCAN | I_FILE1 | 1 | | 0 (0)| 00:00:01 |
|* 13 | FIXED TABLE FIXED INDEX | X$KCCFE (ind:1) | 1 | 13 | 0 (0)| 00:00:01 |
| 14 | TABLE ACCESS CLUSTER | TS$ | 1 | 13 | 1 (0)| 00:00:01 |
|* 15 | INDEX UNIQUE SCAN | I_TS# | 1 | | 0 (0)| 00:00:01 |
| 16 | NESTED LOOPS | | 1 | 245 | 2 (0)| 00:00:01 |
| 17 | NESTED LOOPS | | 1 | 232 | 1 (0)| 00:00:01 |
| 18 | NESTED LOOPS | | 1 | 219 | 1 (0)| 00:00:01 |
| 19 | NESTED LOOPS | | 1 | 208 | 0 (0)| 00:00:01 |
|* 20 | FIXED TABLE FULL | X$KCCFN | 1 | 182 | 0 (0)| 00:00:01 |
|* 21 | FIXED TABLE FIXED INDEX | X$KTFBHC (ind:1) | 1 | 26 | 0 (0)| 00:00:01 |
|* 22 | TABLE ACCESS BY INDEX ROWID | FILE$ | 1 | 11 | 1 (0)| 00:00:01 |
|* 23 | INDEX UNIQUE SCAN | I_FILE1 | 1 | | 0 (0)| 00:00:01 |
|* 24 | FIXED TABLE FIXED INDEX | X$KCCFE (ind:1) | 1 | 13 | 0 (0)| 00:00:01 |
| 25 | TABLE ACCESS CLUSTER | TS$ | 1 | 13 | 1 (0)| 00:00:01 |
|* 26 | INDEX UNIQUE SCAN | I_TS# | 1 | | 0 (0)| 00:00:01 |
|* 27 | HASH JOIN | | 307 | 18420 | 386K(100)| 01:17:24 |
| 28 | VIEW | | 2 | 60 |
