# Very Long Time to Execute
**URL:** https://community.dremio.com/t/very-long-time-to-execute/4569
**Category:** Uncategorized
**Created:** [November 14, 2019, 3:32pm UTC](https://community.dremio.com/t/very-long-time-to-execute/4569 "2019-11-14T15:32:08Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@elshafey](https://community.dremio.com/u/elshafey)
#### Post date: [November 14, 2019, 3:32pm UTC](https://community.dremio.com/t/very-long-time-to-execute/4569/1 "2019-11-14T15:32:08Z")
I am trying to build raw reflection and it takes very long time to execute.
Why thread 04 takes this very long time?
[5efaaab7-f60c-472c-913b-ee6bd6993220.zip](https://community.dremio.com/uploads/short-url/bLVW9L63AQChkPM0pvZsBVCFQBy.zip) (159.5 KB)
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### Author:  [@balaji.ramaswamy](https://community.dremio.com/u/balaji.ramaswamy)
#### Post date: [November 14, 2019, 4:14pm UTC](https://community.dremio.com/t/very-long-time-to-execute/4569/2 "2019-11-14T16:14:52Z")
@elshafey
Problem seems to be with the HASH\_JOIN as the two inputs to the HASH JOIN are
01-xx-09 about 28K records
01-xx-08 about 700 Million
Output of HASH\_JOIN is 01-xx-06 which is 20 Billion records and PARQUET\_WRITER is taking way to long to write these files in 01-xx-01
This looks like an expanding join that is causing the issue. Phase 4 is just waiting on Phase 1 to complete the task