# Consequences of excluding fields from \_source
**URL:** https://discuss.elastic.co/t/consequences-of-excluding-fields-from--source/92833
**Category:** Elasticsearch
**Created:** [July 12, 2017, 3:22pm UTC](https://discuss.elastic.co/t/consequences-of-excluding-fields-from--source/92833 "2017-07-12T15:22:45Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@kasscharal](https://discuss.elastic.co/u/kasscharal)
#### Post date: [July 12, 2017, 3:22pm UTC](https://discuss.elastic.co/t/consequences-of-excluding-fields-from--source/92833/1 "2017-07-12T15:22:45Z")
The documentation describes it as an 'expert-only feature' , and it makes it rather clear that it should be avoided. My case is the following: I use the ingest attachment plugin to index and analyze the contents of PDF files. Here is my pipeline definition:
```
{
"description": "Extract attachment information",
"processors":[
{
"attachment":{
"field": "data",
"target_field": "resume",
"indexed_chars":-1
}
}
]
}
```
However the above results in the unwanted storing of the files's bytestream under the field attachment, together with the actual contents. In order to save some storage capacity I decided to not store it at all. Here is my mapping:
```
{
"_source":{
"excludes":[
"attachment"
]
},
"properties":{
"attachment":{
"type":"text",
"fields":{
"keyword":{
"type":"keyword",
"ignore_above":256
}
}
},
"resume":{
"properties":{
"content":{
"type":"text",
"fields":{
"keyword":{
"type":"keyword",
"ignore_above":256
}
},
"analyzer":"some_language"
}
}
}
}
}
```
This solves my problem (the bytes stream is not returned with my searches), however I'm concerned with the following warning from the [ES docs](https://www.elastic.co/guide/en/elasticsearch/reference/current/mapping-source-field.html#include-exclude), on which I'm hoping for some elaboration:
> 'Removing fields from the \_source has similar downsides to disabling \_source, especially the fact that you cannot reindex documents from one Elasticsearch index to another'
How will excluding the attachment from my \_source affect my ability to re-index if needed? And why? Is there another way to do it? Also will the result of the analysis of resume.content field be transferred to the new index?
I hope I'm specific enough, thank you in advance!
---
### Author:  [@dadoonet](https://discuss.elastic.co/u/dadoonet)
#### Post date: [July 12, 2017, 3:36pm UTC](https://discuss.elastic.co/t/consequences-of-excluding-fields-from--source/92833/2 "2017-07-12T15:36:06Z")
It's better IMO to remove the field with an ingest remove processor.
So the binary BASE64 is not part of the source anymore.
---
### Author:  [@kasscharal](https://discuss.elastic.co/u/kasscharal)
#### Post date: [July 12, 2017, 6:18pm UTC](https://discuss.elastic.co/t/consequences-of-excluding-fields-from--source/92833/3 "2017-07-12T18:18:25Z")
Dear David,
Thank you for your reply. I will look into it, but just so I understand the full idea, why do you think that this would be better? Does it eliminate the problem of re-indexing?
---
### Author:  [@dadoonet](https://discuss.elastic.co/u/dadoonet)
#### Post date: [July 12, 2017, 8:37pm UTC](https://discuss.elastic.co/t/consequences-of-excluding-fields-from--source/92833/4 "2017-07-12T20:37:24Z")
Yes. As it does not alter the `_source` field.
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [August 9, 2017, 8:37pm UTC](https://discuss.elastic.co/t/consequences-of-excluding-fields-from--source/92833/5 "2017-08-09T20:37:42Z")
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