Chiese dedup memory error

there is memory error when deduplicate Chinese data.
```
23/04/19 19:44:17 WARN MemoryStore: Not enough space to cache rdd_7_0 in memory! (computed 176.2 MiB so far)
23/04/19 19:44:17 WARN BlockManager: Block rdd_7_0 could not be removed as it was not found on disk or in memory
23/04/19 19:44:17 WARN BlockManager: Putting block rdd_7_0 failed
23/04/19 19:44:17 WARN MemoryStore: Not enough space to cache rdd_7_2 in memory! (computed 176.2 MiB so far)
23/04/19 19:44:17 WARN BlockManager: Block rdd_7_2 could not be removed as it was not found on disk or in memory
23/04/19 19:44:17 WARN BlockManager: Putting block rdd_7_2 failed
23/04/19 19:44:17 WARN MemoryStore: Not enough space to cache rdd_7_9 in memory! (computed 176.3 MiB so far)
23/04/19 19:44:17 WARN BlockManager: Block rdd_7_9 could not be removed as it was not found on disk or in memory
23/04/19 19:44:17 WARN BlockManager: Putting block rdd_7_9 failed
23/04/19 19:44:19 WARN MemoryStore: Not enough space to cache rdd_7_7 in memory! (computed 176.6 MiB so far)
23/04/19 19:44:19 WARN BlockManager: Block rdd_7_7 could not be removed as it was not found on disk or in memory
23/04/19 19:44:19 WARN BlockManager: Putting block rdd_7_7 failed
23/04/19 19:44:41 WARN BlockManager: Block rdd_7_6 could not be removed as it was not found on disk or in memory
23/04/19 19:44:42 ERROR Executor: Exception in task 6.0 in stage 1.0 (TID 30545)
java.lang.OutOfMemoryError: Java heap space
```